It is highly challenging to precisely compare the impacts of anthropogenic pollutants on the photooxidation of isomeric volatile organic compounds with respect to molecular compositions and particle number/mass concen...It is highly challenging to precisely compare the impacts of anthropogenic pollutants on the photooxidation of isomeric volatile organic compounds with respect to molecular compositions and particle number/mass concentrations of secondary organic aerosols(SOAs).In this study,we conducted a series of well-defined indoor chamber experiments to compare the effects of NO_(x)(NO and NO_(2))on the photooxidation of isomeric monoterpenes ofβ-pinene and limonene.For the photooxidation ofβ-pinene with NO_(x),the increase of the initial concentrations of NO([NO]_(0))shows a monotonous suppression of the particle mass concentration,whereas the increase of[NO_(2)]_(0) shows a monotonous enhancement of the particle mass concentration.For the photooxidation of limonene with NO_(x),the increase of[NO]_(0) exhibits a monotonous suppression of the particle mass concentration,whereas the increase of[NO_(2)]_(0) shows a parabolic trend of the particle mass concentration.Utilizing a newly developed vacuum ultraviolet free electron laser(VUV-FEL),the online threshold photoionization mass spectrometry reveals a series of novel compounds at molecular weight(MW)=232 and 306 for theβ-pinene+NO_(x) system and MW=187,261,280,and 306 for the limonene+NO_(x) system.The molecular structures and formation pathways of these species were inferred,which led to the prediction of the diversity and difference of SOA products(i.e.,ester and peroxide accretion products)formed from different monoterpene precursors.To improve the predictions of future air quality,it is recommended that climate models should incorporate the NO_(x)-driven diurnal photooxidation of monoterpenes for SOA formation mechanisms.展开更多
Background:Limonene is an important monoterpene used as a chemical commodity and precursor for producing biofuels,flavor and medicinal compounds.Results:In this paper,we engineered Escherichia coli by embedding two ex...Background:Limonene is an important monoterpene used as a chemical commodity and precursor for producing biofuels,flavor and medicinal compounds.Results:In this paper,we engineered Escherichia coli by embedding two exogenous genes encoding a limonene synthase(LS)and a geranyl diphosphate synthase(GPPS)for production of limonene.Out of 12 E.coli strains transformed with various plasmids,the best one with p15T7-ls-gpps produced limonene with a titer of 4.87 mg/L.In order to enhance the limonene production,two rate-limiting enzymes in the endogenous MEP pathway of E.coli,1-deoxy-xylulose-5-phosphate synthase(DXS)and isopentenyl diphosphate isomerase(IDI),were overexpressed consecutively on vector pET21a+,resulting in a production of 17.4 mg_(limonene)/L at 48 h.Conclusions:After the preliminary optimization of the medium in a two-phase culture system composed of n-hexadecane(1/50,V_(org)/V_(aq)),the final production of limonene was raised up to 35.8 mg/L,representing approximately a 7-fold improvement compared to the initial titer.展开更多
The monoterpene d limonene inhibit the plasma membrane associated P21 ras expression and the posttranslational isoprenylation of P21 ras , a mechanism that may contribute to its efficacy in the chemoprevent...The monoterpene d limonene inhibit the plasma membrane associated P21 ras expression and the posttranslational isoprenylation of P21 ras , a mechanism that may contribute to its efficacy in the chemoprevention and therapy of chemically induced rodent cancers and some human solid tumor cells. In the present study,the relative abilities of d limonene to inhibit membrane associated P21 ras expression in pancreas tumor cell(PaCa) was carried out with Western blotting, and the inhibition of farnesyl protein transferase (FTPase) activity during the Ras protein isoprenylation and cell proliferation were determined.Concomitantly,the effects of d limonene on P21 ras localization by immunohistochemistry and H ras oncogene expression in PaCa tumor cell line by Northern blotting were observed. The results showed that d limonene inhibited FPTase activity, thus to reduce P21H ras isoprenylation. d limonene could decrease P21 ras membrane association and increase cytosolic accumulation of P21 ras . This phenomenon was also noted when d limonene treated PaCa cells were stained immunohistochemically with anti P21 ras antibody. It is suggested that the inhibition of FPTase activity was closely related with the inhibiton of P21 ras membrane association and the alteration of P21 ras localization. Inhibition of farnesylation of P21 ras altered their intracellular localization and, hence, disrupted their biological activity,but no relationship with H ras oncogene expression was found.展开更多
Syringa species are important ornamentals with strong floral scent,of which monoterpenes are the main component.In this study,a new monoterpene synthase gene,named SoLIM,was collected from the flowers of Syringa oblat...Syringa species are important ornamentals with strong floral scent,of which monoterpenes are the main component.In this study,a new monoterpene synthase gene,named SoLIM,was collected from the flowers of Syringa oblata and S.oblata var.alba using a homologous cloning method.The full-length cDNA of SoLIM was1746 bp and encoded 581 amino acids.Sequence analysis showed that SoLIM contained the DDxxD and RRx8 W motifs,which are two typical conserved monoterpene synthase motifs,and was thus classified as belonging to the Tpsb subfamily.Using quantitative reverse-transcription PCR,SoLIM was significantly expressed in the petals and pistils of S.oblata and S.oblata var.alba,respectively.SoLIM expression peaked earlier than the D-limonene emissions in the diurnal experiments,but occurred later when D-limonene had peaked during the flowering phase,indicating that differences in SoLIM gene expression and D-limonene emissions existed.The synthesis of floral scent is thus associated with diverse regulatory mechanisms that require further investigation.展开更多
Background: Limonene, a major component in citrus oil, has demonstrated anti-cancer effects in preclinical mammary cancer models. However, the effective oral dose translates to a human dose that may not be feasible fo...Background: Limonene, a major component in citrus oil, has demonstrated anti-cancer effects in preclinical mammary cancer models. However, the effective oral dose translates to a human dose that may not be feasible for chronic dosing. We proposed to evaluate topical application of limonene to the breast as an alternative dosing strategy. Materials and Methods: We conducted a mouse disposition study to determine whether limonene would be bioavailable in the mammary tissue after topical application. SKH-1 mice received topical or oral administration of limonene in the form of orange oil every day for 4 weeks. Plasma and mammary pads were collected 4 hrs after the final dosing. We also conducted an exploratory clinical study to evaluate the safety and feasibility of topically applied limonene in the form of orange oil to the breast. Healthy women were recruited to apply orange oil containing massage oil to their breasts daily for four weeks. Safety and feasibility were assessed by reported adverse events, clinical labs, and usage compliance. Pre and post-intervention nipple aspirate fluid (NAF) and plasma were collected for limonene concentration determination. Results: The mouse disposition study showed that topical and oral orange oil administration resulted in similar mammary tissue disposition of limonene with no clinical signs of toxicity. In the clinical study, the topical application of limonene containing massage oil to the breast was found to be safe with high levels of usage compliance for daily application, although NAF and plasma limonene concentrations were not significantly changed after the massage oil application. Conclusions: Our studies showed that limonene is bioavailable in mammary tissue after topical orange oil application in mice and this novel route of administration to the breast is safe and feasible in healthy women.展开更多
Objective: To study gap junction intercellular communication (GJIC), H ras oncogene expression and ras oncogene product (P 21 ras protein) expression in four human solid tumor cell lines, W1-38,CACO 2,A549 and...Objective: To study gap junction intercellular communication (GJIC), H ras oncogene expression and ras oncogene product (P 21 ras protein) expression in four human solid tumor cell lines, W1-38,CACO 2,A549 and PaCa, and the effects of four compounds, Salvia miltiorrhiza derivative (SMD), d Limonene, Turmeric derivative I (TD I) and Turmeric derivative II (TD II), on them. Methods: The abilities of the four solid tumor cell lines to transfer dye to adjacent cells were examined by the scrape loading/dye transfer technique, and the H ras oncogene expression by Northern blotting and P 21 ras protein expression by Western blotting. Results: The results showed the loss of intercellular coupling in PaCa cells, slight GJIC in A549 and CACO 2 cells, and a good GJIC in W1-38 cells. The four compounds could improve the GJIC of PaCa to different extents. The amount of total and membrane associated P 21 ras in PaCa cells were decreased after treatment with SMD, d Limonene and TD I (2.5 μg/ml) for 48 h. Concomitantly, the growth of PaCa cells decreased in soft agar and had enhanced GJIC. The relative potency was found to be:d Limonene>SMD >TD I=TD II. There was no significant effect of the four compounds on H ras oncogene expression. Conclusion: It was suggested that there was an excellent correlation between loss of Lucifer Yellow dye transfer and ras gene mutation rate in the four solid tumor cell lines (ras gene mutation rate inversely correlated with average cell number coupled, r=0.98) i.e., the high ras gene mutation was closely correlated with loss of GJIC in these malignant human tumor cells; The antitumor effect of the monoterpene d Limonene and the phenol compound, SMD, might be related to inhibition of P 21 ras membrane association and enhancement of GJIC, whilst that of the others may be by a different mechanism; The inhibition of P 21 ras membrane association was directly related to the enhancement of gap junction intercellular com munication.展开更多
Ponkan(Citrus reticulate Blanco)is one of the most popular citrus fruits for daily consumption and processing in China.In this study,limonene was removed from ponkan essential oil(PEO)by using an effective methodology...Ponkan(Citrus reticulate Blanco)is one of the most popular citrus fruits for daily consumption and processing in China.In this study,limonene was removed from ponkan essential oil(PEO)by using an effective methodology to estimate the optimum levels of three independent variables of molecular distillation(MD)in order to minimize the limonene content and(b)maximize the removal rate.A three-factor Box-Behnken design(BBD)was employed to evaluate the effect of distilling temperature(45.00~55.00℃),wiper rolling speed(150.00~250.00 r/min)and distilling pressure(25.00~35.00 Pa).The optimum parameters within the experimental range of the variables were extrapolated to be:distilling temperature 47.00℃,wiper rolling speed 203.00 r/min and distilling pressure 30.00 Pa.Optimal values extrapolated by response surface methodology(RSM)for the limonene content and removal rate of the desirable PEO were 47.82%and 84.67%,respectively.展开更多
Ralstonia solanacearum, the causative agent of bacterial wilt, is a soil-borne pathogen that poses a widespread threat to plants in the Solanaceae family. To elucidate the mechanism by which limonene exerts its effect...Ralstonia solanacearum, the causative agent of bacterial wilt, is a soil-borne pathogen that poses a widespread threat to plants in the Solanaceae family. To elucidate the mechanism by which limonene exerts its effects on R. solanacearum, we first assessed the impact of limonene on the physiological indicators of the pathogen and subsequently analyzed its transcriptome and metabolome. Our findings indicate that limonene has a potent inhibitory effect on R. solanacearum, and it also suppresses the formation of the bacterial community biofilm. Limonene primarily regulates the terpene biosynthesis pathway in R. solanacearum, thereby potentially affecting signal transduction in the pathogen and disrupting its normal growth and development. These results significantly enhance our understanding of limonene’s response to the induction of bacterial wilt and provide a reference for further prevention and control of R. solanacearum.展开更多
Astronauts are under high stress for a long time because of the microgravity condition,which leads to anxiety,affects their learning and memory abilities,and seriously impairs the health of astronauts.Aromatherapy can...Astronauts are under high stress for a long time because of the microgravity condition,which leads to anxiety,affects their learning and memory abilities,and seriously impairs the health of astronauts.Aromatherapy can improve the physical and mental health of astronauts in a way that moisturizes them softly and silently.However,the strong volatility of fragrances and inconvenience of aroma treatment greatly limit their application in the field of spaceflight.In this study,reactive mesoporous silica nanoparticles were prepared to encapsulate and slowly release limonene.The limonene loaded nanoparticles were named limonene@mesoporous silica nanoparticles-cyanuric chloride(LE@MSNs-CYC).LE@MSNs-CYC were then applied to wallpaper to improve the convenience of aromatherapy.LE@MSNs-CYC could chemically react with the wallpaper,thus firmly adsorbed on the wallpaper.In the following,the mice were treated with hindlimb unloading(HU)to simulate a microgravity environment.The results showed that 28-day HU led to an increase in the level of anxiety and declines in learning,memory,and physical health in mice.LE@MSNs-CYC showed significant relief effects on anxiety,learning,memory,and physical health of HU treated mice.Subsequently,the molecular mechanisms were explored by hypothalamic-pituitary-adrenal axis related hormones,immune-related cytokines,learning,and memory-related neurotransmitters and proteins.展开更多
Our previous studies had confirmed that the essential oil from Zanthoxylum bungeanum Maxim. （Z. bungeanum oil） could effectively enhance the percutaneous permeation of drug molecules as a natural transdermal penetra...Our previous studies had confirmed that the essential oil from Zanthoxylum bungeanum Maxim. （Z. bungeanum oil） could effectively enhance the percutaneous permeation of drug molecules as a natural transdermal penetration enhancer. The aim of the present study is to investigate and compare the skin penetration enhancement effect of Z. bungeanum oil and its main components on traditional Chinese medicine （TCM） active components. Toxicities of Z. bungeanum oil and three selected terpene compounds （terpinen-4-ol, 1,8-cineole, and limonene） in epidermal keratinocytes （HaCaT） and dermal flbroblast （CCC-ESF-1） cell lines were measured using an MTT （3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide） assay. Five model drugs in TCM external preparations, namely osthole （OT）, tetramethylpyrazine （TMP）, ferulic acid （FA）, puerarin （PR）, and geniposide （GP）, which were selected based on their lipophilicity denoted by IogKo^w, were tested using in vitro permeation studies in which vertical Franz diffusion ceils and rat abdominal skin were employed. The secondary structure changes of skin stratum corneum （SC） and drug thermodynamic activities were investigated to understand their mechanisms of action using Fourier transform infrared （FTIR） spectroscopy and saturation solubility studies, respectively. It was found that Z. bungeanum oil showed lower toxicities in both HaCaT cells and CCC-ESF-1 cells compared with three terpene compounds used alone. The enhancement permeation capacities by all tested agents were in the following increasing order： terpinen-4-ol=1,8-cineole〈limonene〈Z, bungeanum oil. The mechanisms of permeation enhancement suggested that these enhancers promoted the skin permeation of drugs mainly by affecting SC lipids. These results indicated that Z. bungeanum oil exhibited better performance in enhancing the skin permeation of active components in TCM preparations.展开更多
Carum carvi or caraway is traditionally used for treatment of indigestion,pneumonia,and as appetizer,galactagogue,and carminative.Essential oil,fixed oil and many other valuable extractive compounds with industrial ap...Carum carvi or caraway is traditionally used for treatment of indigestion,pneumonia,and as appetizer,galactagogue,and carminative.Essential oil,fixed oil and many other valuable extractive compounds with industrial applications are prepared from caraway.This review article has new deep research on caraway as medicinal plant.For preparing the manuscript,the information was extracted from accessible international databases(Google scholar,PubMed,Science direct,Springer,and Wiley),electronic resources and traditional books by key word of caraway or Carum carvi.The results of traditional studies exhibited that the galactagogue and carminative effects of caraway fruits are superior to other effects.Although,the traditional scholars used it as appetizer,while caraway was the main ingredient of anti-obesity drugs in traditional medicine,which has been confirmed in two modern clinical trials of human studies.Caraway oil in combination with peppermint oil or menthol is used for treatment of functional dyspepsia in clinical studies.Caraway oil topically on abdomen relieves the IBS symptoms in patient.Although,the use of caraway oil is not recommended in adults under 18 years due to insufficient data,but it can topically use as anti-colic and carminative agent in children or infants.The antiaflatoxigenic,antioxidant and antimicrobial effects of caraway oil along with its reputation as spice help the industries to use it as natural preservatives and antioxidant agents.展开更多
Peel essential oil of bergamot （Citrus bergamia Risso） growing in Tunisia was separated by hydrodistillation and obtained in a yield of 9.7%. The oil composition was investigated using GC and GC-MS with two columns ...Peel essential oil of bergamot （Citrus bergamia Risso） growing in Tunisia was separated by hydrodistillation and obtained in a yield of 9.7%. The oil composition was investigated using GC and GC-MS with two columns HP-I and HP-Innowax. Fifteen compounds accounting for 98.52% of the oil were identified. The oil was characterized by bigb content oflimonene （59.21%）, linalool （9.51%） and linalyl acetate （16.83%）.展开更多
Myrtle, Myrtus communis L. （Myrtaceae）, an evergreen shrub also known as wild myrtle, has a history of use as a culinary and medicinal plant. To determine the diversity within the species, plant leaves of myrtle wer...Myrtle, Myrtus communis L. （Myrtaceae）, an evergreen shrub also known as wild myrtle, has a history of use as a culinary and medicinal plant. To determine the diversity within the species, plant leaves of myrtle were collected in 12 natural habitats in Iran for investigation of chemical constituents in the essential oil. Extraction of the essential oils produced yields ranging from 0.7 to 1.5 mL per 100 g dry tissue. An analysis of the oils by GC and GC/MS revealed 40 compounds, constituting 90.1-99.9 % of the essential oils. Chemical constituents varied with the site of sample origin, although the principal essential oil compo- nents from all populations, were pinene （17.5-37.1%）, 1,8-cineole （9.9-29.8 %）, linalool （7.0-23.1%）, and a-ter- pineol （5.3-8.3 %）. Limonene （tr, 22.7 %） was a major constituent in three populations. Characterized chemotypes included Chemotype pinene/1,8-cineole/linalool, Chemotype II： a-pinene/linalool, Chemotype III： a-pinene/1,8- cineole, and Chemotype IV： pinene/1,8-cineole/limonene.The main source of variabifity in chemical composition and oil yield appeared to be differences in environmental conditions and chemotypes as plant populations collected from close geographical areas could be classified in a cluster.展开更多
Cinnamon and lemon are the oldest plants which possess a rising popularity due to their therapeutic potential from centuries. Cinnamomum zeylanicum and lemon (Citrus lemon L.) have been subjected to extensive research...Cinnamon and lemon are the oldest plants which possess a rising popularity due to their therapeutic potential from centuries. Cinnamomum zeylanicum and lemon (Citrus lemon L.) have been subjected to extensive research. Their essential oils were extracted by steam distillation from selected plants and their chemical compositions were determined by the GC-MS system. Cinnamon and lemon essential oils were examined for antioxidant activity by ABTS method which showed the ability to inhibit lipid per-oxidation. On the other hand, in antimicrobial investigations, cinnamon and lemon essential oils have inhibitory effect against Gram positive bacteria (Staphylococcus aureus) and Gram negative bacteria (Escherichia coli) using Muller Hinton agar medium. The essential oils of cinnamon and lemon showed antifungal effects which were tested against (Candida albicans). The volatile oil of cinnamon bark has been found to be highly effective against all the tested bacteria and fungi. However, lemon peel essential oil has shown medium inhibition for Gram positive bacteria (Staphylococcus aureus). On the other hand, the cytotoxic activities of the essential oils were tested on hepatocellular carcinoma and colorectal carcinoma. Essential oils have shown good activities on the cell lines. Essential oil of cinnamon showed more inhibition rate than essential oil of lemon. This study reported the importance of both cinnamon and lemon volatile oils and recommends that cinnamon and lemon can be used as an active therapy for humans.展开更多
Novel preparation method of microencapsules was developed on the basis of the liquid coalescence method followed by phase separation. Oil droplets of limonene dissolving expanded polystyrene as a shell material were f...Novel preparation method of microencapsules was developed on the basis of the liquid coalescence method followed by phase separation. Oil droplets of limonene dissolving expanded polystyrene as a shell material were forced to collide and coalesce with the Isopar oil droplets of core material in the continuous wates phase. When two kinds of oil droplets are collided and coalesced with each other, expanded polystyrene dissolved in the limonene oil may be phase-separated in the oil droplets newly formed to form the microcapsule shell, because the Isopar oil was a poor solvent for expanded polystyrene but a good solvent for the limonene oil. In the experiment, the diameter (or number) of limonene oil droplets dissolving expanded polystyrene was mainly changed, because the coalescence frequency between the droplets is strongly dependent on the number of droplets. Favorable core shell types of microcapsules with the shell thickness from 1.0 to 5.0 μm were able to be prepared under all the experimental conditions adopted here.展开更多
The bioconversion of the hydrophobic and volatile limonene to perillic acid, a potential anticancer agent, by the yeast Yarrowia lipolytica was studied in two steps. Firstly, experimental design was used for process o...The bioconversion of the hydrophobic and volatile limonene to perillic acid, a potential anticancer agent, by the yeast Yarrowia lipolytica was studied in two steps. Firstly, experimental design was used for process optimization using high-purity limonene as substrate and secondly orange essential oil containing 89.1% limonene was used as substrate under the previously optimized conditions. Limonene concentration and pH were identified by fractional factorial design as significant factors and were optimized by central composite design. Under optimized process conditions (0.16% (v/v) limonene;pH 6.9), the 24 h biotransformation process resulted in the accumulation of 0.368 g·L-1 of perillic acid corresponding to a molar yield of 23.1%. A subsequent substrate addition under the same reaction conditions doubled perillic acid concentration to 0.793 g·L-1 and a molar yield of 24.2%. The use of orange essential oil under the optimized reaction conditions increased both perillic acid accumulation and yield to 0.872 g·L-1 and 29.7%, respectively. The robustness of Y. lipolytica allowed the efficient biotransformation of a crude by-product of the citrus industry into a valuable fine chemical.展开更多
Here we report a novel twin polarization angle （TPA） approach in the quantitative chirality detection with the surface sum-frequency generation vibrational spectroscopy （SFG-VS）. Generally, the achiral contributio...Here we report a novel twin polarization angle （TPA） approach in the quantitative chirality detection with the surface sum-frequency generation vibrational spectroscopy （SFG-VS）. Generally, the achiral contribution dominates the surface SFG-VS signal, and the pure chiral signal is usually two or three orders of magnitude smaller. Therefore, it has been difficult to make quantitative detection and analysis of the chiral contributions to the surface SFG- VS signal. In the TPA method, by varying together the polarization angles of the incoming visible light and the sum frequency signal at fixed s or p polarization of the incoming infrared beam, the polarization dependent SFG signal can give not only direct signature of the chiral contribution in the total SFG-VS signal, but also the accurate measurement of the chiral and achiral components in the surface SFG signal. The general description of the TPA method is presented and the experiment test of the TPA approach is also presented for the SFG-VS from the S- and R-limonene chiral liquid surfaces. The most accurate degree of chiral excess values thus obtained for the 2878 cm^-1 spectral peak of the S- and R-limonene liquid surfaces are （23.7±0.4）% and （-25.4±1.3）%, respectively.展开更多
Perillic acid can be obtained from microbial oxidation of the exocyclic methyl group of limonene. Due to the pharmacological potential of such a metabolite, the biotransformation processes leading to its synthesis hav...Perillic acid can be obtained from microbial oxidation of the exocyclic methyl group of limonene. Due to the pharmacological potential of such a metabolite, the biotransformation processes leading to its synthesis have been approached in recent studies. A robust analytical method is needed to assess the performance of such studies. An analytical method was developed and validated to determine perillic acid in the supernatants of a yeast-induced bioconversion of limonene, involving gas chromatography (GC) and an acid-induced precipitation during the sample preparation. GC analysis was performed using a column with polyethylene glycol as stationary phase (HP-Innowax) which resulted in higher loads and better peak shape. The sample preparation involved the supernatant initial filtration and precipitation with 0.6 M HCl followed by centrifugation and dissolution in ethyl acetate. GC analysis conditions were oven from 50°C to 250°C at 20°C·min-1, and then held 5 min (total runtime 15 min). Injector was set at 280°C, and detector at 300°C. Helium was the carrier gas at 1 ml·min-1. Injections of 1.0 μl were at the split ratio 25:1. The method was validated: Linearity with R2 of 0.9992, Accuracy of 98.3% in the range 190 - 950 μg·ml-1;Limit of detection of 10.4 μg·ml-1;Repeatability of 2.1% RSD. Thus, a complete methodology to determine perillic acid in a bioconversion supernatant was developed and validated. This overall approach may be useful for bioconversions of monoterpenes by other microorganisms that metabolize limonene.展开更多
Teucrium polium is a dwarf sub-shrub usually 30-60 cm high with many branches, which is fairly distributed throughout Iran, with its flowering being season mainly from April to July. The plant was collected during its...Teucrium polium is a dwarf sub-shrub usually 30-60 cm high with many branches, which is fairly distributed throughout Iran, with its flowering being season mainly from April to July. The plant was collected during its flowering season in Baghmalek region in the North-East of Khuzestan province, Iran. After the identification of the genus, species and variety of the plant, the dried whole plant （flowers, fruits and the leaves） was steam distilled with different methods. The isolated essential oil was dried over anhydrous sodium sulphate and stored at 4-6 ℃. Analysis of the essential oil was carried out by GC-MS technique. At least 10 major components were identified （3-carene/α-pinene, β-phellandrene, limonene, germacrene, β-bourbonene, β-caryophylene, γ-muurolene, γ-elemene, spathulenol, β-eudesmol） （totally 97.02%）. Also, successive TLC and column chromatography of the essential oil resulted in the separation of four fractions. Based upon 1^H NMR, IR and mass spectra, the fractions with Rf=0.12 and 0.93 were determined as gualol and a mixture of α-pinene, β-phellandrene and limonene, respectively.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22125303,92361302,92061203,22103082,22273101,22288201,and 21327901)the National Key Research and Development Program of China(No.2021YFA1400501)+3 种基金the Innovation Program for Quantum Science and Technology(No.2021ZD0303304)Dalian Institute of Chemical Physics(No.DICPI202437)Chinese Academy of Sciences(No.GJJSTD20220001)the International Partnership Program of CAS(No.121421KYSB20170012)。
文摘It is highly challenging to precisely compare the impacts of anthropogenic pollutants on the photooxidation of isomeric volatile organic compounds with respect to molecular compositions and particle number/mass concentrations of secondary organic aerosols(SOAs).In this study,we conducted a series of well-defined indoor chamber experiments to compare the effects of NO_(x)(NO and NO_(2))on the photooxidation of isomeric monoterpenes ofβ-pinene and limonene.For the photooxidation ofβ-pinene with NO_(x),the increase of the initial concentrations of NO([NO]_(0))shows a monotonous suppression of the particle mass concentration,whereas the increase of[NO_(2)]_(0) shows a monotonous enhancement of the particle mass concentration.For the photooxidation of limonene with NO_(x),the increase of[NO]_(0) exhibits a monotonous suppression of the particle mass concentration,whereas the increase of[NO_(2)]_(0) shows a parabolic trend of the particle mass concentration.Utilizing a newly developed vacuum ultraviolet free electron laser(VUV-FEL),the online threshold photoionization mass spectrometry reveals a series of novel compounds at molecular weight(MW)=232 and 306 for theβ-pinene+NO_(x) system and MW=187,261,280,and 306 for the limonene+NO_(x) system.The molecular structures and formation pathways of these species were inferred,which led to the prediction of the diversity and difference of SOA products(i.e.,ester and peroxide accretion products)formed from different monoterpene precursors.To improve the predictions of future air quality,it is recommended that climate models should incorporate the NO_(x)-driven diurnal photooxidation of monoterpenes for SOA formation mechanisms.
基金financially supported by the National Natural Science Foundation of China(No.21276082)Ministry of Science and Technology,P.R.China(Nos.2011CB710800)Shanghai Commission of Science and Technology(No.11431921600).
文摘Background:Limonene is an important monoterpene used as a chemical commodity and precursor for producing biofuels,flavor and medicinal compounds.Results:In this paper,we engineered Escherichia coli by embedding two exogenous genes encoding a limonene synthase(LS)and a geranyl diphosphate synthase(GPPS)for production of limonene.Out of 12 E.coli strains transformed with various plasmids,the best one with p15T7-ls-gpps produced limonene with a titer of 4.87 mg/L.In order to enhance the limonene production,two rate-limiting enzymes in the endogenous MEP pathway of E.coli,1-deoxy-xylulose-5-phosphate synthase(DXS)and isopentenyl diphosphate isomerase(IDI),were overexpressed consecutively on vector pET21a+,resulting in a production of 17.4 mg_(limonene)/L at 48 h.Conclusions:After the preliminary optimization of the medium in a two-phase culture system composed of n-hexadecane(1/50,V_(org)/V_(aq)),the final production of limonene was raised up to 35.8 mg/L,representing approximately a 7-fold improvement compared to the initial titer.
文摘The monoterpene d limonene inhibit the plasma membrane associated P21 ras expression and the posttranslational isoprenylation of P21 ras , a mechanism that may contribute to its efficacy in the chemoprevention and therapy of chemically induced rodent cancers and some human solid tumor cells. In the present study,the relative abilities of d limonene to inhibit membrane associated P21 ras expression in pancreas tumor cell(PaCa) was carried out with Western blotting, and the inhibition of farnesyl protein transferase (FTPase) activity during the Ras protein isoprenylation and cell proliferation were determined.Concomitantly,the effects of d limonene on P21 ras localization by immunohistochemistry and H ras oncogene expression in PaCa tumor cell line by Northern blotting were observed. The results showed that d limonene inhibited FPTase activity, thus to reduce P21H ras isoprenylation. d limonene could decrease P21 ras membrane association and increase cytosolic accumulation of P21 ras . This phenomenon was also noted when d limonene treated PaCa cells were stained immunohistochemically with anti P21 ras antibody. It is suggested that the inhibition of FPTase activity was closely related with the inhibiton of P21 ras membrane association and the alteration of P21 ras localization. Inhibition of farnesylation of P21 ras altered their intracellular localization and, hence, disrupted their biological activity,but no relationship with H ras oncogene expression was found.
基金supported by the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality(IDHT20180509)the National Natural Science foundation of China(31201645)+1 种基金the Beijing Municipal Natural Science Foundation(6172006)key project of Beijing Municipal Education Commission(KZ201510020021)
文摘Syringa species are important ornamentals with strong floral scent,of which monoterpenes are the main component.In this study,a new monoterpene synthase gene,named SoLIM,was collected from the flowers of Syringa oblata and S.oblata var.alba using a homologous cloning method.The full-length cDNA of SoLIM was1746 bp and encoded 581 amino acids.Sequence analysis showed that SoLIM contained the DDxxD and RRx8 W motifs,which are two typical conserved monoterpene synthase motifs,and was thus classified as belonging to the Tpsb subfamily.Using quantitative reverse-transcription PCR,SoLIM was significantly expressed in the petals and pistils of S.oblata and S.oblata var.alba,respectively.SoLIM expression peaked earlier than the D-limonene emissions in the diurnal experiments,but occurred later when D-limonene had peaked during the flowering phase,indicating that differences in SoLIM gene expression and D-limonene emissions existed.The synthesis of floral scent is thus associated with diverse regulatory mechanisms that require further investigation.
文摘Background: Limonene, a major component in citrus oil, has demonstrated anti-cancer effects in preclinical mammary cancer models. However, the effective oral dose translates to a human dose that may not be feasible for chronic dosing. We proposed to evaluate topical application of limonene to the breast as an alternative dosing strategy. Materials and Methods: We conducted a mouse disposition study to determine whether limonene would be bioavailable in the mammary tissue after topical application. SKH-1 mice received topical or oral administration of limonene in the form of orange oil every day for 4 weeks. Plasma and mammary pads were collected 4 hrs after the final dosing. We also conducted an exploratory clinical study to evaluate the safety and feasibility of topically applied limonene in the form of orange oil to the breast. Healthy women were recruited to apply orange oil containing massage oil to their breasts daily for four weeks. Safety and feasibility were assessed by reported adverse events, clinical labs, and usage compliance. Pre and post-intervention nipple aspirate fluid (NAF) and plasma were collected for limonene concentration determination. Results: The mouse disposition study showed that topical and oral orange oil administration resulted in similar mammary tissue disposition of limonene with no clinical signs of toxicity. In the clinical study, the topical application of limonene containing massage oil to the breast was found to be safe with high levels of usage compliance for daily application, although NAF and plasma limonene concentrations were not significantly changed after the massage oil application. Conclusions: Our studies showed that limonene is bioavailable in mammary tissue after topical orange oil application in mice and this novel route of administration to the breast is safe and feasible in healthy women.
文摘Objective: To study gap junction intercellular communication (GJIC), H ras oncogene expression and ras oncogene product (P 21 ras protein) expression in four human solid tumor cell lines, W1-38,CACO 2,A549 and PaCa, and the effects of four compounds, Salvia miltiorrhiza derivative (SMD), d Limonene, Turmeric derivative I (TD I) and Turmeric derivative II (TD II), on them. Methods: The abilities of the four solid tumor cell lines to transfer dye to adjacent cells were examined by the scrape loading/dye transfer technique, and the H ras oncogene expression by Northern blotting and P 21 ras protein expression by Western blotting. Results: The results showed the loss of intercellular coupling in PaCa cells, slight GJIC in A549 and CACO 2 cells, and a good GJIC in W1-38 cells. The four compounds could improve the GJIC of PaCa to different extents. The amount of total and membrane associated P 21 ras in PaCa cells were decreased after treatment with SMD, d Limonene and TD I (2.5 μg/ml) for 48 h. Concomitantly, the growth of PaCa cells decreased in soft agar and had enhanced GJIC. The relative potency was found to be:d Limonene>SMD >TD I=TD II. There was no significant effect of the four compounds on H ras oncogene expression. Conclusion: It was suggested that there was an excellent correlation between loss of Lucifer Yellow dye transfer and ras gene mutation rate in the four solid tumor cell lines (ras gene mutation rate inversely correlated with average cell number coupled, r=0.98) i.e., the high ras gene mutation was closely correlated with loss of GJIC in these malignant human tumor cells; The antitumor effect of the monoterpene d Limonene and the phenol compound, SMD, might be related to inhibition of P 21 ras membrane association and enhancement of GJIC, whilst that of the others may be by a different mechanism; The inhibition of P 21 ras membrane association was directly related to the enhancement of gap junction intercellular com munication.
文摘Ponkan(Citrus reticulate Blanco)is one of the most popular citrus fruits for daily consumption and processing in China.In this study,limonene was removed from ponkan essential oil(PEO)by using an effective methodology to estimate the optimum levels of three independent variables of molecular distillation(MD)in order to minimize the limonene content and(b)maximize the removal rate.A three-factor Box-Behnken design(BBD)was employed to evaluate the effect of distilling temperature(45.00~55.00℃),wiper rolling speed(150.00~250.00 r/min)and distilling pressure(25.00~35.00 Pa).The optimum parameters within the experimental range of the variables were extrapolated to be:distilling temperature 47.00℃,wiper rolling speed 203.00 r/min and distilling pressure 30.00 Pa.Optimal values extrapolated by response surface methodology(RSM)for the limonene content and removal rate of the desirable PEO were 47.82%and 84.67%,respectively.
文摘Ralstonia solanacearum, the causative agent of bacterial wilt, is a soil-borne pathogen that poses a widespread threat to plants in the Solanaceae family. To elucidate the mechanism by which limonene exerts its effects on R. solanacearum, we first assessed the impact of limonene on the physiological indicators of the pathogen and subsequently analyzed its transcriptome and metabolome. Our findings indicate that limonene has a potent inhibitory effect on R. solanacearum, and it also suppresses the formation of the bacterial community biofilm. Limonene primarily regulates the terpene biosynthesis pathway in R. solanacearum, thereby potentially affecting signal transduction in the pathogen and disrupting its normal growth and development. These results significantly enhance our understanding of limonene’s response to the induction of bacterial wilt and provide a reference for further prevention and control of R. solanacearum.
基金financially supported by the National High Technology Research and Development Program(2016YFA0200303)the Beijing Natural Science Foundation(L172046,2192057)the National Natural Science Foundation of China(31771095,21875254 , 21905283).
文摘Astronauts are under high stress for a long time because of the microgravity condition,which leads to anxiety,affects their learning and memory abilities,and seriously impairs the health of astronauts.Aromatherapy can improve the physical and mental health of astronauts in a way that moisturizes them softly and silently.However,the strong volatility of fragrances and inconvenience of aroma treatment greatly limit their application in the field of spaceflight.In this study,reactive mesoporous silica nanoparticles were prepared to encapsulate and slowly release limonene.The limonene loaded nanoparticles were named limonene@mesoporous silica nanoparticles-cyanuric chloride(LE@MSNs-CYC).LE@MSNs-CYC were then applied to wallpaper to improve the convenience of aromatherapy.LE@MSNs-CYC could chemically react with the wallpaper,thus firmly adsorbed on the wallpaper.In the following,the mice were treated with hindlimb unloading(HU)to simulate a microgravity environment.The results showed that 28-day HU led to an increase in the level of anxiety and declines in learning,memory,and physical health in mice.LE@MSNs-CYC showed significant relief effects on anxiety,learning,memory,and physical health of HU treated mice.Subsequently,the molecular mechanisms were explored by hypothalamic-pituitary-adrenal axis related hormones,immune-related cytokines,learning,and memory-related neurotransmitters and proteins.
基金supported by the Beijing Natural Science Foundation(No.7132127)the Innovative Research Team in Beijing University of Chinese Medicine(No.2011-CXTD-13),China
文摘Our previous studies had confirmed that the essential oil from Zanthoxylum bungeanum Maxim. （Z. bungeanum oil） could effectively enhance the percutaneous permeation of drug molecules as a natural transdermal penetration enhancer. The aim of the present study is to investigate and compare the skin penetration enhancement effect of Z. bungeanum oil and its main components on traditional Chinese medicine （TCM） active components. Toxicities of Z. bungeanum oil and three selected terpene compounds （terpinen-4-ol, 1,8-cineole, and limonene） in epidermal keratinocytes （HaCaT） and dermal flbroblast （CCC-ESF-1） cell lines were measured using an MTT （3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide） assay. Five model drugs in TCM external preparations, namely osthole （OT）, tetramethylpyrazine （TMP）, ferulic acid （FA）, puerarin （PR）, and geniposide （GP）, which were selected based on their lipophilicity denoted by IogKo^w, were tested using in vitro permeation studies in which vertical Franz diffusion ceils and rat abdominal skin were employed. The secondary structure changes of skin stratum corneum （SC） and drug thermodynamic activities were investigated to understand their mechanisms of action using Fourier transform infrared （FTIR） spectroscopy and saturation solubility studies, respectively. It was found that Z. bungeanum oil showed lower toxicities in both HaCaT cells and CCC-ESF-1 cells compared with three terpene compounds used alone. The enhancement permeation capacities by all tested agents were in the following increasing order： terpinen-4-ol=1,8-cineole〈limonene〈Z, bungeanum oil. The mechanisms of permeation enhancement suggested that these enhancers promoted the skin permeation of drugs mainly by affecting SC lipids. These results indicated that Z. bungeanum oil exhibited better performance in enhancing the skin permeation of active components in TCM preparations.
文摘Carum carvi or caraway is traditionally used for treatment of indigestion,pneumonia,and as appetizer,galactagogue,and carminative.Essential oil,fixed oil and many other valuable extractive compounds with industrial applications are prepared from caraway.This review article has new deep research on caraway as medicinal plant.For preparing the manuscript,the information was extracted from accessible international databases(Google scholar,PubMed,Science direct,Springer,and Wiley),electronic resources and traditional books by key word of caraway or Carum carvi.The results of traditional studies exhibited that the galactagogue and carminative effects of caraway fruits are superior to other effects.Although,the traditional scholars used it as appetizer,while caraway was the main ingredient of anti-obesity drugs in traditional medicine,which has been confirmed in two modern clinical trials of human studies.Caraway oil in combination with peppermint oil or menthol is used for treatment of functional dyspepsia in clinical studies.Caraway oil topically on abdomen relieves the IBS symptoms in patient.Although,the use of caraway oil is not recommended in adults under 18 years due to insufficient data,but it can topically use as anti-colic and carminative agent in children or infants.The antiaflatoxigenic,antioxidant and antimicrobial effects of caraway oil along with its reputation as spice help the industries to use it as natural preservatives and antioxidant agents.
文摘Peel essential oil of bergamot （Citrus bergamia Risso） growing in Tunisia was separated by hydrodistillation and obtained in a yield of 9.7%. The oil composition was investigated using GC and GC-MS with two columns HP-I and HP-Innowax. Fifteen compounds accounting for 98.52% of the oil were identified. The oil was characterized by bigb content oflimonene （59.21%）, linalool （9.51%） and linalyl acetate （16.83%）.
基金supported by Deputy of Researches and Technology,Islamic Azad University of Shahrekord Branch,Iran(No Grant.,IAUSHK-6121)
文摘Myrtle, Myrtus communis L. （Myrtaceae）, an evergreen shrub also known as wild myrtle, has a history of use as a culinary and medicinal plant. To determine the diversity within the species, plant leaves of myrtle were collected in 12 natural habitats in Iran for investigation of chemical constituents in the essential oil. Extraction of the essential oils produced yields ranging from 0.7 to 1.5 mL per 100 g dry tissue. An analysis of the oils by GC and GC/MS revealed 40 compounds, constituting 90.1-99.9 % of the essential oils. Chemical constituents varied with the site of sample origin, although the principal essential oil compo- nents from all populations, were pinene （17.5-37.1%）, 1,8-cineole （9.9-29.8 %）, linalool （7.0-23.1%）, and a-ter- pineol （5.3-8.3 %）. Limonene （tr, 22.7 %） was a major constituent in three populations. Characterized chemotypes included Chemotype pinene/1,8-cineole/linalool, Chemotype II： a-pinene/linalool, Chemotype III： a-pinene/1,8- cineole, and Chemotype IV： pinene/1,8-cineole/limonene.The main source of variabifity in chemical composition and oil yield appeared to be differences in environmental conditions and chemotypes as plant populations collected from close geographical areas could be classified in a cluster.
文摘Cinnamon and lemon are the oldest plants which possess a rising popularity due to their therapeutic potential from centuries. Cinnamomum zeylanicum and lemon (Citrus lemon L.) have been subjected to extensive research. Their essential oils were extracted by steam distillation from selected plants and their chemical compositions were determined by the GC-MS system. Cinnamon and lemon essential oils were examined for antioxidant activity by ABTS method which showed the ability to inhibit lipid per-oxidation. On the other hand, in antimicrobial investigations, cinnamon and lemon essential oils have inhibitory effect against Gram positive bacteria (Staphylococcus aureus) and Gram negative bacteria (Escherichia coli) using Muller Hinton agar medium. The essential oils of cinnamon and lemon showed antifungal effects which were tested against (Candida albicans). The volatile oil of cinnamon bark has been found to be highly effective against all the tested bacteria and fungi. However, lemon peel essential oil has shown medium inhibition for Gram positive bacteria (Staphylococcus aureus). On the other hand, the cytotoxic activities of the essential oils were tested on hepatocellular carcinoma and colorectal carcinoma. Essential oils have shown good activities on the cell lines. Essential oil of cinnamon showed more inhibition rate than essential oil of lemon. This study reported the importance of both cinnamon and lemon volatile oils and recommends that cinnamon and lemon can be used as an active therapy for humans.
文摘Novel preparation method of microencapsules was developed on the basis of the liquid coalescence method followed by phase separation. Oil droplets of limonene dissolving expanded polystyrene as a shell material were forced to collide and coalesce with the Isopar oil droplets of core material in the continuous wates phase. When two kinds of oil droplets are collided and coalesced with each other, expanded polystyrene dissolved in the limonene oil may be phase-separated in the oil droplets newly formed to form the microcapsule shell, because the Isopar oil was a poor solvent for expanded polystyrene but a good solvent for the limonene oil. In the experiment, the diameter (or number) of limonene oil droplets dissolving expanded polystyrene was mainly changed, because the coalescence frequency between the droplets is strongly dependent on the number of droplets. Favorable core shell types of microcapsules with the shell thickness from 1.0 to 5.0 μm were able to be prepared under all the experimental conditions adopted here.
文摘The bioconversion of the hydrophobic and volatile limonene to perillic acid, a potential anticancer agent, by the yeast Yarrowia lipolytica was studied in two steps. Firstly, experimental design was used for process optimization using high-purity limonene as substrate and secondly orange essential oil containing 89.1% limonene was used as substrate under the previously optimized conditions. Limonene concentration and pH were identified by fractional factorial design as significant factors and were optimized by central composite design. Under optimized process conditions (0.16% (v/v) limonene;pH 6.9), the 24 h biotransformation process resulted in the accumulation of 0.368 g·L-1 of perillic acid corresponding to a molar yield of 23.1%. A subsequent substrate addition under the same reaction conditions doubled perillic acid concentration to 0.793 g·L-1 and a molar yield of 24.2%. The use of orange essential oil under the optimized reaction conditions increased both perillic acid accumulation and yield to 0.872 g·L-1 and 29.7%, respectively. The robustness of Y. lipolytica allowed the efficient biotransformation of a crude by-product of the citrus industry into a valuable fine chemical.
文摘Here we report a novel twin polarization angle （TPA） approach in the quantitative chirality detection with the surface sum-frequency generation vibrational spectroscopy （SFG-VS）. Generally, the achiral contribution dominates the surface SFG-VS signal, and the pure chiral signal is usually two or three orders of magnitude smaller. Therefore, it has been difficult to make quantitative detection and analysis of the chiral contributions to the surface SFG- VS signal. In the TPA method, by varying together the polarization angles of the incoming visible light and the sum frequency signal at fixed s or p polarization of the incoming infrared beam, the polarization dependent SFG signal can give not only direct signature of the chiral contribution in the total SFG-VS signal, but also the accurate measurement of the chiral and achiral components in the surface SFG signal. The general description of the TPA method is presented and the experiment test of the TPA approach is also presented for the SFG-VS from the S- and R-limonene chiral liquid surfaces. The most accurate degree of chiral excess values thus obtained for the 2878 cm^-1 spectral peak of the S- and R-limonene liquid surfaces are （23.7±0.4）% and （-25.4±1.3）%, respectively.
文摘Perillic acid can be obtained from microbial oxidation of the exocyclic methyl group of limonene. Due to the pharmacological potential of such a metabolite, the biotransformation processes leading to its synthesis have been approached in recent studies. A robust analytical method is needed to assess the performance of such studies. An analytical method was developed and validated to determine perillic acid in the supernatants of a yeast-induced bioconversion of limonene, involving gas chromatography (GC) and an acid-induced precipitation during the sample preparation. GC analysis was performed using a column with polyethylene glycol as stationary phase (HP-Innowax) which resulted in higher loads and better peak shape. The sample preparation involved the supernatant initial filtration and precipitation with 0.6 M HCl followed by centrifugation and dissolution in ethyl acetate. GC analysis conditions were oven from 50°C to 250°C at 20°C·min-1, and then held 5 min (total runtime 15 min). Injector was set at 280°C, and detector at 300°C. Helium was the carrier gas at 1 ml·min-1. Injections of 1.0 μl were at the split ratio 25:1. The method was validated: Linearity with R2 of 0.9992, Accuracy of 98.3% in the range 190 - 950 μg·ml-1;Limit of detection of 10.4 μg·ml-1;Repeatability of 2.1% RSD. Thus, a complete methodology to determine perillic acid in a bioconversion supernatant was developed and validated. This overall approach may be useful for bioconversions of monoterpenes by other microorganisms that metabolize limonene.
文摘Teucrium polium is a dwarf sub-shrub usually 30-60 cm high with many branches, which is fairly distributed throughout Iran, with its flowering being season mainly from April to July. The plant was collected during its flowering season in Baghmalek region in the North-East of Khuzestan province, Iran. After the identification of the genus, species and variety of the plant, the dried whole plant （flowers, fruits and the leaves） was steam distilled with different methods. The isolated essential oil was dried over anhydrous sodium sulphate and stored at 4-6 ℃. Analysis of the essential oil was carried out by GC-MS technique. At least 10 major components were identified （3-carene/α-pinene, β-phellandrene, limonene, germacrene, β-bourbonene, β-caryophylene, γ-muurolene, γ-elemene, spathulenol, β-eudesmol） （totally 97.02%）. Also, successive TLC and column chromatography of the essential oil resulted in the separation of four fractions. Based upon 1^H NMR, IR and mass spectra, the fractions with Rf=0.12 and 0.93 were determined as gualol and a mixture of α-pinene, β-phellandrene and limonene, respectively.
