Comparative antioxidant activities of the water and ethanol extracts obtained from dried citrus fruit (Citrus unshiu) peel were determined using chemical and biochemical in vitro assays. Chemical assays were used for ...Comparative antioxidant activities of the water and ethanol extracts obtained from dried citrus fruit (Citrus unshiu) peel were determined using chemical and biochemical in vitro assays. Chemical assays were used for evaluation of 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, hydrogen peroxide scavenging, and reducing power of both extracts and their total phenolic, flavonoid and tannin contents and antioxidant activities were investigated. Biochemical assays were performed to evaluate the inhibition activities of AAPH-induced rat RBC hemolysis and Fe2+-induced lipid peroxidation using rat brain tissue cells. Linear correlation between the antioxidant activities of both extracts were determined by chemical assays, and total phenolic, flavonoid and tannin contents was observed in concentration-dependent mode. Both extracts showed >95% DPPH radical scavenging and >85% hydrogen peroxide scavenging, and higher reducing capacity at the same level of 3200 ppm. In the inhibition activity of AAPH-induced hemolysis, water extracts showed a strong activity in concentration-dependent mode up to 1600 ppm with no statistical difference found between 1600 and 3200 ppm (P > 0.05). In the inhibition activity of Fe2+-induced lipid peroxidation, ethanol extracts showed the higher inhibition percentage of lipid peroxidation than those of water extracts at the same concentration with no significant difference (P > 0.05) found in the range of 800 to 3200 ppm. The extracts of dried Citrus unshiu peel may be considered as potential antioxidant ingredients of functional food depending on the conditions at which reactive oxygen species are implicated.展开更多
The chemical composition, antioxidant and antibacterial activities of essential oil from peel of Citrus unshiuwhich cultivated in South Korea were investigated. Eight compounds were identified as l-limonene (88.11%), ...The chemical composition, antioxidant and antibacterial activities of essential oil from peel of Citrus unshiuwhich cultivated in South Korea were investigated. Eight compounds were identified as l-limonene (88.11%), γ-terpinene (4.66%), cyclohexane, 2,4-diisopropenyl-1-methyl-1-vinyl (1.82%), diethyl phthalate (1.02%), β-linalool (0.97%), β-myrcene (0.91%), α-farnesene (0.91%) and o-cymene (0.85%) by GC-MS. The SC50values of this essential oil on DPPH and superoxide anion were 0.21 and 0.22% (v/v), respectively. The results of zone of inhibition, MIC, MBC and cell viability demonstrated the essential oil of-Citrus unshiupeel displayed antibacterial effect against B. cereus KCTC 14042, B. subtilis ATCC 6633 and S. aureusATCC 6538. The release of cell material and potassium ion from the B. subtilis ATCC 6633 cells treated with essential oil was further investigated. SEM observation also revealed the damaging effect of the essential oil on the morphology of B. subtilisATCC 6633 cells at minimum inhibitory concentration.展开更多
In order to provide theoretical references for early-maturing Citrus unshiu Marc. in terms of fruit thinning, timely fertilization and harvesting, as wel as for for-mulation of of Early-maturing Citrus unshiu Marc. Cu...In order to provide theoretical references for early-maturing Citrus unshiu Marc. in terms of fruit thinning, timely fertilization and harvesting, as wel as for for-mulation of of Early-maturing Citrus unshiu Marc. Cultivation Technique Standards in Guizhou Province, the dynamic changes of fruit longitudinal diameter and trans-verse diameter of 11-year-old and 12-year-old early maturing Citrus unshiu Marc. were tested in two consecutive years and the effects of single-fruit bearing branch on fruit growth and development were compared. The results showed annual varia-tion of longitudinal and transverse diameter of the fruit in Guizhou grew faster at the beginning and then slowed down gradual y, maintaining a slow-growth period after October; the growth curve final y was flat in mature stage. General y, the growth and development stage of fruit showed four growth peaks, showing an in-creasing S-shape curve and fruit net increase also had four growth peaks with a double S-shape curve. Specifical y, longitudinal diameters growth alternated with transverse diameter growth and the former proved much stronger. In terms of ef-fects of single-fruit bearing branch on longitudinal and transverse diameter growth, the number of reserved fruits had direct effects on the growth, net increase of weight, time of growth peak, fluctuation and the number of growth peak. The growth and development, and quality of fruits in the treatments with two or three fruits re-served on single fruit-bearing branch proved better compared with the control with four left fruits. It suggested that early June and early July are the best time for fer-tilization of early-maturing Citrus unshiu Marc. in Guizhou Pprovince and would have better effect if combined with foliage spraying. The suitable harvest time is in the end of October. The preferred number of reserved fruit on single fruit-bearing branch is 2-3. In actual production, the implementation of flower and fruit thinning should also takes tree age, balance of tree vigor, strength of fruit bearing branch, alternate bearing phenomenon and other factors into consideration.展开更多
In order to change the universal phenomenon of alternate bearing of early- grown Satsuma orange （Citrus unshiu Marc.） in north Guizhou province, and provide references for setting scientific cultivation techniques a...In order to change the universal phenomenon of alternate bearing of early- grown Satsuma orange （Citrus unshiu Marc.） in north Guizhou province, and provide references for setting scientific cultivation techniques and rational management mea- sures for Satsuma orange gardens, cultivation techniques for controlling alternate bearing of the early-grown Satsuma orange were tested and optimized for 7 years （2005 to 2011）. The results showed that production of local early-grown Satsuma or- ange orchards could be significantly improved through the application of cultivation techniques such as rational trimming, strengthening soil, fertilizer and water manage- ment, conducting flower and fruit management pertinently, effective and comprehen- sive control of disease and insects. The yield difference between ＂on＂ and ＂off＂ years was 10%-15%, and the orchards with serious alternate bearing phenomenon were changed into the one with high and stable yield. Meanwhile, the commercial rate of early-grown Satsuma orange fruit enhanced, leading to good economic benefits.展开更多
The application of plant extracts in the green synthesis of silver nanoparticles(AgNPs)has attracted significant attention owing to their eco-friendliness and cost-effective features.However,nanoparticles synthesized ...The application of plant extracts in the green synthesis of silver nanoparticles(AgNPs)has attracted significant attention owing to their eco-friendliness and cost-effective features.However,nanoparticles synthesized from plant materials may also display unique physicochemical properties.This study described an improved synthesis process for silver nanoparticles(AgNPs)from the peel of the Citrus unshiu fruit,an agricultural waste product.In addition to evaluating the produced AgNPs'physico-chemical characteristics,the research also examines their antibacterial and cytotoxic/anticancer capa-bilities.The color change from yellow to dark brown was observed immediately when 20 ml of Citrus unshiu fruit peel extract was added to 0.5 g of silver nitrate.A surface plasmon resonance band at 424 nm revealed by ultra-violet spectroscopy was used as additional confirmation that AgNP had formed.The scanning electron microscope(SEM),and the transmission electron microscope(TEM),revealed spherical-shaped NPs with a mean size of 23 nm.Furthermore,X-ray diffraction(XRD)confirmed the high crystallinity of the obtained NPs while Fourier transform infrared spectroscopy(FTIR)confirmed the bioreducing capacity of the Citrus unshiu fruit peel extract.The minimum inhibitory concentration(MIC)(31.25 mg/mL)of AgNPs significantly revealed a strong dose-dependent antibacterial effect on Staphy-lococcus aureus and Bacillus cereus.In contrast,their impact on gram-negative bacteria,such as Escher-ichia coli and Salmonella typhimurium,displayed an MIC of 250 mg/mL.The assessment of cytotoxicity on human embryonic kidney cells(HEK293)and lung cancer cells(A549)through a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay revealed no detectable cytotoxic effects.The IC 50 values were determined as 37.73±0.34 mg/mL for HEK293 and 56.37±0.73 mg/mL for A549,indicating the absence of significant adverse impacts on these cell lines.The anticancer drug doxorubicin was used as a reference standard,and had an IC 50 value of 1.22±0.09 and 0.76±0.12 mg/mL against HEK293 and A549 cells,respectively.The results show that AgNPs synthesized from Citrus unshiu fruit peel could serve as antibacterial agents that may in the future be optimized for us in for example nanofiltration systems.展开更多
文摘Comparative antioxidant activities of the water and ethanol extracts obtained from dried citrus fruit (Citrus unshiu) peel were determined using chemical and biochemical in vitro assays. Chemical assays were used for evaluation of 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, hydrogen peroxide scavenging, and reducing power of both extracts and their total phenolic, flavonoid and tannin contents and antioxidant activities were investigated. Biochemical assays were performed to evaluate the inhibition activities of AAPH-induced rat RBC hemolysis and Fe2+-induced lipid peroxidation using rat brain tissue cells. Linear correlation between the antioxidant activities of both extracts were determined by chemical assays, and total phenolic, flavonoid and tannin contents was observed in concentration-dependent mode. Both extracts showed >95% DPPH radical scavenging and >85% hydrogen peroxide scavenging, and higher reducing capacity at the same level of 3200 ppm. In the inhibition activity of AAPH-induced hemolysis, water extracts showed a strong activity in concentration-dependent mode up to 1600 ppm with no statistical difference found between 1600 and 3200 ppm (P > 0.05). In the inhibition activity of Fe2+-induced lipid peroxidation, ethanol extracts showed the higher inhibition percentage of lipid peroxidation than those of water extracts at the same concentration with no significant difference (P > 0.05) found in the range of 800 to 3200 ppm. The extracts of dried Citrus unshiu peel may be considered as potential antioxidant ingredients of functional food depending on the conditions at which reactive oxygen species are implicated.
文摘The chemical composition, antioxidant and antibacterial activities of essential oil from peel of Citrus unshiuwhich cultivated in South Korea were investigated. Eight compounds were identified as l-limonene (88.11%), γ-terpinene (4.66%), cyclohexane, 2,4-diisopropenyl-1-methyl-1-vinyl (1.82%), diethyl phthalate (1.02%), β-linalool (0.97%), β-myrcene (0.91%), α-farnesene (0.91%) and o-cymene (0.85%) by GC-MS. The SC50values of this essential oil on DPPH and superoxide anion were 0.21 and 0.22% (v/v), respectively. The results of zone of inhibition, MIC, MBC and cell viability demonstrated the essential oil of-Citrus unshiupeel displayed antibacterial effect against B. cereus KCTC 14042, B. subtilis ATCC 6633 and S. aureusATCC 6538. The release of cell material and potassium ion from the B. subtilis ATCC 6633 cells treated with essential oil was further investigated. SEM observation also revealed the damaging effect of the essential oil on the morphology of B. subtilisATCC 6633 cells at minimum inhibitory concentration.
文摘In order to provide theoretical references for early-maturing Citrus unshiu Marc. in terms of fruit thinning, timely fertilization and harvesting, as wel as for for-mulation of of Early-maturing Citrus unshiu Marc. Cultivation Technique Standards in Guizhou Province, the dynamic changes of fruit longitudinal diameter and trans-verse diameter of 11-year-old and 12-year-old early maturing Citrus unshiu Marc. were tested in two consecutive years and the effects of single-fruit bearing branch on fruit growth and development were compared. The results showed annual varia-tion of longitudinal and transverse diameter of the fruit in Guizhou grew faster at the beginning and then slowed down gradual y, maintaining a slow-growth period after October; the growth curve final y was flat in mature stage. General y, the growth and development stage of fruit showed four growth peaks, showing an in-creasing S-shape curve and fruit net increase also had four growth peaks with a double S-shape curve. Specifical y, longitudinal diameters growth alternated with transverse diameter growth and the former proved much stronger. In terms of ef-fects of single-fruit bearing branch on longitudinal and transverse diameter growth, the number of reserved fruits had direct effects on the growth, net increase of weight, time of growth peak, fluctuation and the number of growth peak. The growth and development, and quality of fruits in the treatments with two or three fruits re-served on single fruit-bearing branch proved better compared with the control with four left fruits. It suggested that early June and early July are the best time for fer-tilization of early-maturing Citrus unshiu Marc. in Guizhou Pprovince and would have better effect if combined with foliage spraying. The suitable harvest time is in the end of October. The preferred number of reserved fruit on single fruit-bearing branch is 2-3. In actual production, the implementation of flower and fruit thinning should also takes tree age, balance of tree vigor, strength of fruit bearing branch, alternate bearing phenomenon and other factors into consideration.
文摘In order to change the universal phenomenon of alternate bearing of early- grown Satsuma orange （Citrus unshiu Marc.） in north Guizhou province, and provide references for setting scientific cultivation techniques and rational management mea- sures for Satsuma orange gardens, cultivation techniques for controlling alternate bearing of the early-grown Satsuma orange were tested and optimized for 7 years （2005 to 2011）. The results showed that production of local early-grown Satsuma or- ange orchards could be significantly improved through the application of cultivation techniques such as rational trimming, strengthening soil, fertilizer and water manage- ment, conducting flower and fruit management pertinently, effective and comprehen- sive control of disease and insects. The yield difference between ＂on＂ and ＂off＂ years was 10%-15%, and the orchards with serious alternate bearing phenomenon were changed into the one with high and stable yield. Meanwhile, the commercial rate of early-grown Satsuma orange fruit enhanced, leading to good economic benefits.
基金funding from South African Coal,Oil,and Gas Corporation-National Research Foundation(SASOL-NRF)Uni-versity Collaborative Research Grants(Grant No.138626).
文摘The application of plant extracts in the green synthesis of silver nanoparticles(AgNPs)has attracted significant attention owing to their eco-friendliness and cost-effective features.However,nanoparticles synthesized from plant materials may also display unique physicochemical properties.This study described an improved synthesis process for silver nanoparticles(AgNPs)from the peel of the Citrus unshiu fruit,an agricultural waste product.In addition to evaluating the produced AgNPs'physico-chemical characteristics,the research also examines their antibacterial and cytotoxic/anticancer capa-bilities.The color change from yellow to dark brown was observed immediately when 20 ml of Citrus unshiu fruit peel extract was added to 0.5 g of silver nitrate.A surface plasmon resonance band at 424 nm revealed by ultra-violet spectroscopy was used as additional confirmation that AgNP had formed.The scanning electron microscope(SEM),and the transmission electron microscope(TEM),revealed spherical-shaped NPs with a mean size of 23 nm.Furthermore,X-ray diffraction(XRD)confirmed the high crystallinity of the obtained NPs while Fourier transform infrared spectroscopy(FTIR)confirmed the bioreducing capacity of the Citrus unshiu fruit peel extract.The minimum inhibitory concentration(MIC)(31.25 mg/mL)of AgNPs significantly revealed a strong dose-dependent antibacterial effect on Staphy-lococcus aureus and Bacillus cereus.In contrast,their impact on gram-negative bacteria,such as Escher-ichia coli and Salmonella typhimurium,displayed an MIC of 250 mg/mL.The assessment of cytotoxicity on human embryonic kidney cells(HEK293)and lung cancer cells(A549)through a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay revealed no detectable cytotoxic effects.The IC 50 values were determined as 37.73±0.34 mg/mL for HEK293 and 56.37±0.73 mg/mL for A549,indicating the absence of significant adverse impacts on these cell lines.The anticancer drug doxorubicin was used as a reference standard,and had an IC 50 value of 1.22±0.09 and 0.76±0.12 mg/mL against HEK293 and A549 cells,respectively.The results show that AgNPs synthesized from Citrus unshiu fruit peel could serve as antibacterial agents that may in the future be optimized for us in for example nanofiltration systems.
