The first total synthesis of(+)-taberdicatine B and(+)-tabernabovine B has been accomplished in 10steps with 26.9% overall yield and 15 steps with 7.3% overall yield,respectively.The prominent features of this efficie...The first total synthesis of(+)-taberdicatine B and(+)-tabernabovine B has been accomplished in 10steps with 26.9% overall yield and 15 steps with 7.3% overall yield,respectively.The prominent features of this efficient synthetic strategy include the following:(1)(+)-Taberdicatine B and(+)-tabernabovine B were accessed from common advanced intermediates by varying the substituents;(2) A one-pot asymmetric bromocyclization/hydrolysis was explored to assemble HPI skeleton;(3) Dieckmann condensation to form β-keto ester for the assembly of seven-membered ring;(4) An ester reduction/amide semireduction/cyclization sequence was applied to form the cage-like framework.展开更多
A novel organocatalytic asymmetric approach to oxazoline derivatives that proceeds through Mannich/annulation reaction of N-acylimines with 3-chlorooxindoles is presented.This strategy provides an efficient and conven...A novel organocatalytic asymmetric approach to oxazoline derivatives that proceeds through Mannich/annulation reaction of N-acylimines with 3-chlorooxindoles is presented.This strategy provides an efficient and convenient method to access enantioenriched oxazolines such as valuable chiral S,Noxazoline ligand as well as Ferrox ligand in high yields with excellent enantio–and diastereroselectivity.Furthermore,the optically active oxazoline products can be converted to valuable 1,2-amino alcohols.More importantly,the synthetic utility of this transformation is demonstrated in the expeditious assembly of chiral Phox-type ligand,which shows excellent catalytic activities.展开更多
A novel synthetic strategy towards pH-responsive aggregation-induced emission (AIE)-active tetraphenylethene (TPE)- functionalized polyethylene-based block copolymers is presented. Tris(3-(4-(l,2,2-triphenylvinyl)phen...A novel synthetic strategy towards pH-responsive aggregation-induced emission (AIE)-active tetraphenylethene (TPE)- functionalized polyethylene-based block copolymers is presented. Tris(3-(4-(l,2,2-triphenylvinyl)phenoxy)propyl)borane was used to initiate the polyhomologation of dimethylsulfoxonium methylide to afford well-defined a-TPE-ω-OH linear polyethylenes (PE). The terminal hydroxyl groups were transformed to atom transfer radical polymerization (ATRP) initiating sites by esterification with bromoisobutyryl bromide, followed by polymerization of rert-butyl acrylate (tBA) to provide TPE-PE-b-PtBA block copolymers. After hydrolysis of the rBu group to COOH group, the corresponding pH-responsive TPE-PE-b-PAA block copolymers were obtained. All synthesized block copolymers revealed AIE behavior either in solution or bulk. Due to the pH-responsivity of PAA chains, the aggregation state at different pH and consequently the fluorescence intensity changed. Also, the synthesized block copolymers exhibited ion-specificity fluorescence properties.展开更多
AIM: Chemokines and their receptors are crucial for immune responses in HCV and HIV infection. RANTES gene polymorphisms lead to altered gene expression and influence the natural course of HIV infection. Therefore,the...AIM: Chemokines and their receptors are crucial for immune responses in HCV and HIV infection. RANTES gene polymorphisms lead to altered gene expression and influence the natural course of HIV infection. Therefore,these mutations may also affect the course of HIV/HCV coinfection.METHODS: We determined allele frequencies of RANTES-403 (G→A), RANTES-28 (C→G) and RANTESIN1.1 (T→C) polymorphisms using real-time PCR and hybridization probes in patients with HIV (n = 85), HCV (n= 112), HIV/HCV coinfection (n = 121), and 109 healthy controls. Furthermore, HIV and HCV loads as well as CD4+ and CD8+ cell counts were compared between different RANTES genotypes.RESULTS: Frequencies of RANTES-403 A, RANTES-28 G and RANTES-IN1.1 C alleles were higher in HIV infected patients than in healthy controls (-403: 28.2% vs 15.1%,P = 0.002; -28: 5.4% vs 2.8%, not significant; IN1.1:19.0% vs 11.0%, P = 0.038). In HIV/HCV coinfected patients, these RANTES alleles were less frequent than in patients with HIV infection alone (15.4% P = 0.002;1.7%; P = 0.048; 12.0%; not significant). Frequencies of these alleles were not significantly different between HIV/HCV positive patients, HCV positive patients and healthy controls.CONCLUSION: All three RANTES polymorphisms showed increased frequencies of the variant allele exclusively in patients with HIV monoinfection. The finding that the frequencies of these alleles remained unaltered in HIV/HCV coinfected patients suggests that HCV coinfection interferes with selection processes associated with these alleles in HIV infection.展开更多
2-Arylbenzothiazoles formed in good yields（65-90%） by the condensation of aminothiophenols with aromatic aldehydes using P_2O_5 at ambient temperature.
In this paper, we present the effect of varied illumination levels on the electrical properties of the organic blend bulk heterojuction （BHJ） photodiode. To prepare the BHJ blend, poly（2-methoxy-5（2P-ethylhexyloxy...In this paper, we present the effect of varied illumination levels on the electrical properties of the organic blend bulk heterojuction （BHJ） photodiode. To prepare the BHJ blend, poly（2-methoxy-5（2P-ethylhexyloxy） phenyleneviny- lene （MEH-PPV） and aluminum-tris-（8-hydroxyquinoline） （Alq3） are used as donor and acceptor materials, respectively. In order to fabricate the photodiode, a 40-nm thick film of poly（3, 4-ethylendioxytbiophene）：poly（styrensulfonate） （PE- DOT：PSS） is primarily deposited on a cleaned ITO coated glass substrate by spin coating technique. The organic photo- sensitive blend is later spun coated on the PEDOT：PSS layer, followed by the lithium fluoride （LiF） and aluminium （A1） thin films deposition by thermal evaporation. The optical properties of the MEH-PPV：Alq3 blend thin films are investigated using photoluminescence （PL） and UV-Vis spectroscopy. The photodiode shows good photo-current response as a function of variable illumination levels. The responsivity value - 8 mA/W at 3 V is found and the ratio of photo-current to dark current （lph/IDark） is found to be 1.24.展开更多
Objective:To investigate the butanol fraction of the water/acetone extract and isolate of the new flavonoids from Launeae arboescens.Methods:The compounds were isolated by liquid chromatographic methods and their stru...Objective:To investigate the butanol fraction of the water/acetone extract and isolate of the new flavonoids from Launeae arboescens.Methods:The compounds were isolated by liquid chromatographic methods and their structures were identified by using spectroscopic analysis.Results:The isolated compounds were identified as:7-0-[α-rhamnopyranosyl 4',5,6-Trihydroxy flavone 1,4',5'-Di-Methoxy 7-(5"-Me Hexan)1-oyl flavanone 2,3"-isopropyl pyrano[1":7,4":6]3',4',5',5-Tetrahydroxy flavanone 3,5,4',5'-Tri-Hydroxy 7-(3"-Me butan)-yl flavanone 4.5,7-Dihydroxy-2',4',5'-trimethoxy-isoflavanone 5,5,6,7,4'-tetrahydroxy flavonol 6,7-O-[α-rhamnopyranosyl-(1->6)-β-glucopyranosyl]-4',5,7-tri-hydroxy-flavanone 7,7-O-[α-rhamnopyranosyl-(1->6)-β-glucopyranosyl]3',5-Dihydroxy 4'-Methoxy flavanone 8.Conclusions:The presence of different types of bioactive flavonoids in Launeae arhoescens extract can explain the large ethnopharmacological uses and the potential activity of this medicinal plant.展开更多
AIM:To study the pharmacological profile and inhibition of smooth muscle contraction by YFa and its analogs in conjunction with their receptor selectivity. METHODS:The effects of YFa and its analogs (D-Ala2) YFa, Y (D...AIM:To study the pharmacological profile and inhibition of smooth muscle contraction by YFa and its analogs in conjunction with their receptor selectivity. METHODS:The effects of YFa and its analogs (D-Ala2) YFa, Y (D-Ala2) GFMKKKFMRF amide and Des-Phe-YGGFMKKKFMR amide in guinea pig ileum (GPI) and mouse vas deferens (MVD) motility were studied using an isolated tissue organ bath system, and morphine and DynA (1-13) served as controls. Acetylcholine was used for muscle stimulation. The observations were validated by specific antagonist pretreatment experiments using naloxonazine, naltrindole and norbinaltor-phimine norBNI. RESULTS:YFa did not demonstrate significant inhibition of GPI muscle contraction as compared with mor-phine (15% vs 62%, P = 0.0002), but moderate inhibition of MVD muscle contraction, indicating the role of κ opioid receptors in the contraction. A moderate inhibition of GPI muscles by (Des-Phe) YFa revealed the role of anti-opiate receptors in the smooth muscle contraction. (D-Ala-2) YFa showed significant inhibition of smooth muscle contraction, indicating the involvement of mainly δ receptors in MVD contraction. These results were supported by specific antagonist pretreatment assays. CONCLUSION:YFa revealed its side-effect-free analgesic properties with regard to arrest of gastroin-testinal transit. The study provides evidences for the involvement of κ and anti-opioid receptors in smooth muscle contraction.展开更多
The construction of high color purity and high resolution organic light-emitting diodes(OLEDs)is facilitated by the development of highly-efficient organic luminescent materials with narrow-band emission.Herein,in ord...The construction of high color purity and high resolution organic light-emitting diodes(OLEDs)is facilitated by the development of highly-efficient organic luminescent materials with narrow-band emission.Herein,in order to address the problem of broad emission spectra of organic luminescent materials,an effective molecular design strategy is presented to reduce the full width at half maximum(FWHM)of emission by integrating the steric hindrance effect in the pyrene system.As the bulky group was introduced into the 2-position,compounds 5 not only show a relative high quantum yield(>0.31)in the solid state,but also can suppress the molecular rotation of triphenylamine(TPA)at the 3-position to narrow the FWHM in the solid state compared to that in solution.Compound 5c containing biphenyl units exhibits a maximum emission peak at 484 nm with a quantum yield of 0.38 and FWHM value of 49 nm in the solid state.展开更多
Two bis-naphthalimide-based supramolecular gelators(NN-3 and NN-4)with a little difference of position of amino groups were designed and synthesized for the detection of oxaloyl chloride and phosgene.Energy transfer c...Two bis-naphthalimide-based supramolecular gelators(NN-3 and NN-4)with a little difference of position of amino groups were designed and synthesized for the detection of oxaloyl chloride and phosgene.Energy transfer could be occurred between two naphthalimide groups in molecules NN-3 and NN-4.Yellow gels NN-3 and NN-4 were formed in some mixed solvents,and nanofibers with different size were obtained in these gels.The self-assembly processes of NN-3 and NN-4 in different solvents were investigated by UV-vis absorption,fluorescent spectra,SEM,FTIR,XRD and NMR.Gelators NN-3 and NN-4 could selectively detect oxaloyl chloride in solution and film states,but detect phosgene only in solution.NN-3exhibited the ratiometric detection ability towards oxaloyl chloride and phosgene with the low limit of detection(LOD)of 210 nmol/L and 90 nmol/L,respectively.NN-4 as the corresponding control sample,it owned the higher LOD towards oxaloyl chloride and phosgene of 12.4μmol/L and 64μmol/L,respectively.Interestingly,films NN-3 and NN-4 could sensitively detect oxaloyl chloride gases with the low LOD of2.0 ppm and 8.34 ppm,respectively.The detection mechanisms of NN-3 and NN-4 were well studied by1H NMR titration,HRMS and theoretical calculation.展开更多
Protein to protein interactions leading to homo/heteromerization of receptor is well documented in literature. These interactions leading to dimeric/oligomers formation of receptors are known to modulate their functio...Protein to protein interactions leading to homo/heteromerization of receptor is well documented in literature. These interactions leading to dimeric/oligomers formation of receptors are known to modulate their function, particularly in case of G-protein coupled receptors. The opioid receptor heteromers having changed pharmacological properties than the constituent protomers provides preferences for novel drug targets that could lead to potential analgesicactivity devoid of tolerance and physical dependence. Heterodimerization of opioid receptors appears to generate novel binding properties with improved specificity and lack of side effects. Further the molecules which can interact simultaneously to both the protomers of the heteromer, or to both the binding sites(orthosteric and allosteric) of a receptor protein could be potential therapeutic molecules. This review highlights the recent advancements in exploring the plausible role of heteromerization of opioid receptors in induction of tolerance free antinociception.展开更多
Multiple contiguous quaternary carbon stereocenters(CQS) are highly challenging, yet important structural motifs in organic synthesis. Here, we describe a visible light induced catalytic [2 + 2] cycloaddition approach...Multiple contiguous quaternary carbon stereocenters(CQS) are highly challenging, yet important structural motifs in organic synthesis. Here, we describe a visible light induced catalytic [2 + 2] cycloaddition approach that constructed up to four CQS in a pentacyclic fused ring system diastereoselectively, from the readily accessible dienamides with pendent heteroaryls. Variously substituted dienamides have been cyclized with heteroaryls to provide a range of novel CQS-containing scaffolds(26 examples, up to 96%yield and >20:1 dr ratio). Mechanistic studies revealed that it may proceed through an uncommon β-C radical initiated 7-endo cyclization from the biradical intermediate.展开更多
Essential oil from the leaves of Pistacia lentiscus L. growing in the Oran region in the west of Algeria was obtained by hydrodistillation with a 1.26 % yield on a dry weight basis. Spectrophotometric analyses were em...Essential oil from the leaves of Pistacia lentiscus L. growing in the Oran region in the west of Algeria was obtained by hydrodistillation with a 1.26 % yield on a dry weight basis. Spectrophotometric analyses were employed to highlight the scavenger capacity of this oil using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. Twenty compounds were identified by GC and CG/MS analyses, and the main part of the compounds of the oil was terpinene-4-ol (41.24%) and α-terpineol (7.31%), α-pinene (9.48%), limonene (09.11%), β-myrcene (10.5%), p-cymene (8.67%) and α-phellandrene (2.20%), β-caryophyllene (12.62%) as major compounds. The DPPH test shows that Pistacia lentiscus essential oil possesses antiradical activity. A linear correlation (correlation coefficient R<sup>2</sup> = 0.995, P Pistacia lentiscus essential oil.展开更多
A novel method for the asymmetric synthesis of 1,7-annulated indazoles has been developed via bifunctional Brønsted base catalyzed cascade reaction.This process enabled the formation of multiple chiral centers in...A novel method for the asymmetric synthesis of 1,7-annulated indazoles has been developed via bifunctional Brønsted base catalyzed cascade reaction.This process enabled the formation of multiple chiral centers including a quaternary carbon center in high yields with excellent diastereoselectivities and enantioselectivities.The reaction exhibited broad functional group tolerance and mild reaction conditions.展开更多
The metal coordination complex K4[Fe（CN）6] is an efficient and environmentally benign catalyst for the syn- thesis of imidazolines and benzimidazoles from various aldehydes and 1,2-diamines in aqueous medium at room...The metal coordination complex K4[Fe（CN）6] is an efficient and environmentally benign catalyst for the syn- thesis of imidazolines and benzimidazoles from various aldehydes and 1,2-diamines in aqueous medium at room temperature. This protocol gives excellent yield of product with desired purity.展开更多
A catalyst-free and atom-economical[4+3]cycloaddition of azadienes with C,N-cyclic azomethine imines has been developed,providing an efficient and environmentally benign access to 1,2,4-triazepines with high diastereo...A catalyst-free and atom-economical[4+3]cycloaddition of azadienes with C,N-cyclic azomethine imines has been developed,providing an efficient and environmentally benign access to 1,2,4-triazepines with high diastereoselectivities and yields.This reaction can be performed in 2-methyltetrahydrofuran under mild conditions smoothly.展开更多
A highly efficient base-mediated diastereoselective[4+1]cycloaddition of ortho-tosylaminophenyl-substituted p-QMs with 3-chlorooxindoles has been developed to afford 3,2’-pyrrolidinyl spirooxindoles in high yields wi...A highly efficient base-mediated diastereoselective[4+1]cycloaddition of ortho-tosylaminophenyl-substituted p-QMs with 3-chlorooxindoles has been developed to afford 3,2’-pyrrolidinyl spirooxindoles in high yields with high diastereoselectivity through a domino 1,6-addition/cyclization sequence.This reaction exhibits broad substrate scope and excellent functional group tolerance.展开更多
A highly efficient and environmentally benign 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with 5-alkenyl thiazolones and 2-arylidenindane-1,3-diones is developed for the construction of congested quatern...A highly efficient and environmentally benign 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with 5-alkenyl thiazolones and 2-arylidenindane-1,3-diones is developed for the construction of congested quaternary spiro-carbon centers.All these transformations can be smoothly performed in ethanol at room temperature,providing a catalyst-free and atom-economical access to diversely substituted novel isoquinoline-fused spirocycles in almost quantitative yields with high diastereoselectivities.The promising anti-tumor activity of these structurally novel spirocyclic compounds is reported as well.展开更多
This study focuses on the synthesis and characterization of a novel magnetic nanocomposite 2,4,6-trihydrazino-1,3,5-triazine(THDT)-fimctionalized with silica-coated iron oxide magnetic nanoparticles(MNPs).This nanocom...This study focuses on the synthesis and characterization of a novel magnetic nanocomposite 2,4,6-trihydrazino-1,3,5-triazine(THDT)-fimctionalized with silica-coated iron oxide magnetic nanoparticles(MNPs).This nanocomposite has porous morphology decorated with the spherical MNPs.Through co-precipitation of iron salts,MNPs were obtained.The prepared THDT was placed on the chlorine surface-modified MNPs.The present environment-friendly nanocatalyst intensely accelerated the synthesis of highly functionalized tetra-hydrobenzo[b]pyran derivatives as well as reduced the reaction times and increased yields of the products.展开更多
基金the Qingdao Marine Science and Technology Center(No.2022QNLM030003-2)the Fundamental Research Funds for the Central Universities,Taishan Scholar Program of Shandong Province(No.tsqn202103152)National Natural Science Foundation of China(No.22171251) for financial support。
文摘The first total synthesis of(+)-taberdicatine B and(+)-tabernabovine B has been accomplished in 10steps with 26.9% overall yield and 15 steps with 7.3% overall yield,respectively.The prominent features of this efficient synthetic strategy include the following:(1)(+)-Taberdicatine B and(+)-tabernabovine B were accessed from common advanced intermediates by varying the substituents;(2) A one-pot asymmetric bromocyclization/hydrolysis was explored to assemble HPI skeleton;(3) Dieckmann condensation to form β-keto ester for the assembly of seven-membered ring;(4) An ester reduction/amide semireduction/cyclization sequence was applied to form the cage-like framework.
基金Qingdao Marine Science and Technology Center(No.2022QNLM030003–2)the Fundamental Research Funds for the Central Universities,Taishan Scholar Program of Shandong Province(No.tsqn202103152)+2 种基金National Natural Science Foundation of China(No.22201270)Natural Science Foundation of Shandong Province(No.ZR2021QB033)the National Key Research and Development Program of China(No.2022YFC2804400)for financial support。
文摘A novel organocatalytic asymmetric approach to oxazoline derivatives that proceeds through Mannich/annulation reaction of N-acylimines with 3-chlorooxindoles is presented.This strategy provides an efficient and convenient method to access enantioenriched oxazolines such as valuable chiral S,Noxazoline ligand as well as Ferrox ligand in high yields with excellent enantio–and diastereroselectivity.Furthermore,the optically active oxazoline products can be converted to valuable 1,2-amino alcohols.More importantly,the synthetic utility of this transformation is demonstrated in the expeditious assembly of chiral Phox-type ligand,which shows excellent catalytic activities.
基金supported by King Abdullah University of Science and Technology (KAUST)
文摘A novel synthetic strategy towards pH-responsive aggregation-induced emission (AIE)-active tetraphenylethene (TPE)- functionalized polyethylene-based block copolymers is presented. Tris(3-(4-(l,2,2-triphenylvinyl)phenoxy)propyl)borane was used to initiate the polyhomologation of dimethylsulfoxonium methylide to afford well-defined a-TPE-ω-OH linear polyethylenes (PE). The terminal hydroxyl groups were transformed to atom transfer radical polymerization (ATRP) initiating sites by esterification with bromoisobutyryl bromide, followed by polymerization of rert-butyl acrylate (tBA) to provide TPE-PE-b-PtBA block copolymers. After hydrolysis of the rBu group to COOH group, the corresponding pH-responsive TPE-PE-b-PAA block copolymers were obtained. All synthesized block copolymers revealed AIE behavior either in solution or bulk. Due to the pH-responsivity of PAA chains, the aggregation state at different pH and consequently the fluorescence intensity changed. Also, the synthesized block copolymers exhibited ion-specificity fluorescence properties.
文摘AIM: Chemokines and their receptors are crucial for immune responses in HCV and HIV infection. RANTES gene polymorphisms lead to altered gene expression and influence the natural course of HIV infection. Therefore,these mutations may also affect the course of HIV/HCV coinfection.METHODS: We determined allele frequencies of RANTES-403 (G→A), RANTES-28 (C→G) and RANTESIN1.1 (T→C) polymorphisms using real-time PCR and hybridization probes in patients with HIV (n = 85), HCV (n= 112), HIV/HCV coinfection (n = 121), and 109 healthy controls. Furthermore, HIV and HCV loads as well as CD4+ and CD8+ cell counts were compared between different RANTES genotypes.RESULTS: Frequencies of RANTES-403 A, RANTES-28 G and RANTES-IN1.1 C alleles were higher in HIV infected patients than in healthy controls (-403: 28.2% vs 15.1%,P = 0.002; -28: 5.4% vs 2.8%, not significant; IN1.1:19.0% vs 11.0%, P = 0.038). In HIV/HCV coinfected patients, these RANTES alleles were less frequent than in patients with HIV infection alone (15.4% P = 0.002;1.7%; P = 0.048; 12.0%; not significant). Frequencies of these alleles were not significantly different between HIV/HCV positive patients, HCV positive patients and healthy controls.CONCLUSION: All three RANTES polymorphisms showed increased frequencies of the variant allele exclusively in patients with HIV monoinfection. The finding that the frequencies of these alleles remained unaltered in HIV/HCV coinfected patients suggests that HCV coinfection interferes with selection processes associated with these alleles in HIV infection.
基金the financial support from Department of Science and Technology,New Delhi under Fast Track Young Scientist programme(No.SR/FTP/CS-82/2007).
文摘2-Arylbenzothiazoles formed in good yields（65-90%） by the condensation of aminothiophenols with aromatic aldehydes using P_2O_5 at ambient temperature.
基金Project supported by the Long Term Research Grant Scheme(LRGS),Ministry of Higher Education,Malaysia(Grant No.LR003/2011A)
文摘In this paper, we present the effect of varied illumination levels on the electrical properties of the organic blend bulk heterojuction （BHJ） photodiode. To prepare the BHJ blend, poly（2-methoxy-5（2P-ethylhexyloxy） phenyleneviny- lene （MEH-PPV） and aluminum-tris-（8-hydroxyquinoline） （Alq3） are used as donor and acceptor materials, respectively. In order to fabricate the photodiode, a 40-nm thick film of poly（3, 4-ethylendioxytbiophene）：poly（styrensulfonate） （PE- DOT：PSS） is primarily deposited on a cleaned ITO coated glass substrate by spin coating technique. The organic photo- sensitive blend is later spun coated on the PEDOT：PSS layer, followed by the lithium fluoride （LiF） and aluminium （A1） thin films deposition by thermal evaporation. The optical properties of the MEH-PPV：Alq3 blend thin films are investigated using photoluminescence （PL） and UV-Vis spectroscopy. The photodiode shows good photo-current response as a function of variable illumination levels. The responsivity value - 8 mA/W at 3 V is found and the ratio of photo-current to dark current （lph/IDark） is found to be 1.24.
基金Supported by MESRS-Algeria(Grant No.E03820100011)
文摘Objective:To investigate the butanol fraction of the water/acetone extract and isolate of the new flavonoids from Launeae arboescens.Methods:The compounds were isolated by liquid chromatographic methods and their structures were identified by using spectroscopic analysis.Results:The isolated compounds were identified as:7-0-[α-rhamnopyranosyl 4',5,6-Trihydroxy flavone 1,4',5'-Di-Methoxy 7-(5"-Me Hexan)1-oyl flavanone 2,3"-isopropyl pyrano[1":7,4":6]3',4',5',5-Tetrahydroxy flavanone 3,5,4',5'-Tri-Hydroxy 7-(3"-Me butan)-yl flavanone 4.5,7-Dihydroxy-2',4',5'-trimethoxy-isoflavanone 5,5,6,7,4'-tetrahydroxy flavonol 6,7-O-[α-rhamnopyranosyl-(1->6)-β-glucopyranosyl]-4',5,7-tri-hydroxy-flavanone 7,7-O-[α-rhamnopyranosyl-(1->6)-β-glucopyranosyl]3',5-Dihydroxy 4'-Methoxy flavanone 8.Conclusions:The presence of different types of bioactive flavonoids in Launeae arhoescens extract can explain the large ethnopharmacological uses and the potential activity of this medicinal plant.
基金Supported by Council of Scientific and Industrial Research,Delhi
文摘AIM:To study the pharmacological profile and inhibition of smooth muscle contraction by YFa and its analogs in conjunction with their receptor selectivity. METHODS:The effects of YFa and its analogs (D-Ala2) YFa, Y (D-Ala2) GFMKKKFMRF amide and Des-Phe-YGGFMKKKFMR amide in guinea pig ileum (GPI) and mouse vas deferens (MVD) motility were studied using an isolated tissue organ bath system, and morphine and DynA (1-13) served as controls. Acetylcholine was used for muscle stimulation. The observations were validated by specific antagonist pretreatment experiments using naloxonazine, naltrindole and norbinaltor-phimine norBNI. RESULTS:YFa did not demonstrate significant inhibition of GPI muscle contraction as compared with mor-phine (15% vs 62%, P = 0.0002), but moderate inhibition of MVD muscle contraction, indicating the role of κ opioid receptors in the contraction. A moderate inhibition of GPI muscles by (Des-Phe) YFa revealed the role of anti-opiate receptors in the smooth muscle contraction. (D-Ala-2) YFa showed significant inhibition of smooth muscle contraction, indicating the involvement of mainly δ receptors in MVD contraction. These results were supported by specific antagonist pretreatment assays. CONCLUSION:YFa revealed its side-effect-free analgesic properties with regard to arrest of gastroin-testinal transit. The study provides evidences for the involvement of κ and anti-opioid receptors in smooth muscle contraction.
文摘The construction of high color purity and high resolution organic light-emitting diodes(OLEDs)is facilitated by the development of highly-efficient organic luminescent materials with narrow-band emission.Herein,in order to address the problem of broad emission spectra of organic luminescent materials,an effective molecular design strategy is presented to reduce the full width at half maximum(FWHM)of emission by integrating the steric hindrance effect in the pyrene system.As the bulky group was introduced into the 2-position,compounds 5 not only show a relative high quantum yield(>0.31)in the solid state,but also can suppress the molecular rotation of triphenylamine(TPA)at the 3-position to narrow the FWHM in the solid state compared to that in solution.Compound 5c containing biphenyl units exhibits a maximum emission peak at 484 nm with a quantum yield of 0.38 and FWHM value of 49 nm in the solid state.
基金financially supported by the National Natural Science Foundation of China(No.U1704164)the Basic Research Project of Henan Provincial Key Scientific Research Project(No.22ZX002)。
文摘Two bis-naphthalimide-based supramolecular gelators(NN-3 and NN-4)with a little difference of position of amino groups were designed and synthesized for the detection of oxaloyl chloride and phosgene.Energy transfer could be occurred between two naphthalimide groups in molecules NN-3 and NN-4.Yellow gels NN-3 and NN-4 were formed in some mixed solvents,and nanofibers with different size were obtained in these gels.The self-assembly processes of NN-3 and NN-4 in different solvents were investigated by UV-vis absorption,fluorescent spectra,SEM,FTIR,XRD and NMR.Gelators NN-3 and NN-4 could selectively detect oxaloyl chloride in solution and film states,but detect phosgene only in solution.NN-3exhibited the ratiometric detection ability towards oxaloyl chloride and phosgene with the low limit of detection(LOD)of 210 nmol/L and 90 nmol/L,respectively.NN-4 as the corresponding control sample,it owned the higher LOD towards oxaloyl chloride and phosgene of 12.4μmol/L and 64μmol/L,respectively.Interestingly,films NN-3 and NN-4 could sensitively detect oxaloyl chloride gases with the low LOD of2.0 ppm and 8.34 ppm,respectively.The detection mechanisms of NN-3 and NN-4 were well studied by1H NMR titration,HRMS and theoretical calculation.
基金Supported by Council of Scientific and Industrial Research
文摘Protein to protein interactions leading to homo/heteromerization of receptor is well documented in literature. These interactions leading to dimeric/oligomers formation of receptors are known to modulate their function, particularly in case of G-protein coupled receptors. The opioid receptor heteromers having changed pharmacological properties than the constituent protomers provides preferences for novel drug targets that could lead to potential analgesicactivity devoid of tolerance and physical dependence. Heterodimerization of opioid receptors appears to generate novel binding properties with improved specificity and lack of side effects. Further the molecules which can interact simultaneously to both the protomers of the heteromer, or to both the binding sites(orthosteric and allosteric) of a receptor protein could be potential therapeutic molecules. This review highlights the recent advancements in exploring the plausible role of heteromerization of opioid receptors in induction of tolerance free antinociception.
基金supported by the National Natural Science Foundation of China(Nos.82122063,81991522 and 81973232)Shandong Science Fund for Distinguished Young Scholars(No.ZR2020JQ32)the Fundamental Research Funds for the Central Universities(No.202041003)。
文摘Multiple contiguous quaternary carbon stereocenters(CQS) are highly challenging, yet important structural motifs in organic synthesis. Here, we describe a visible light induced catalytic [2 + 2] cycloaddition approach that constructed up to four CQS in a pentacyclic fused ring system diastereoselectively, from the readily accessible dienamides with pendent heteroaryls. Variously substituted dienamides have been cyclized with heteroaryls to provide a range of novel CQS-containing scaffolds(26 examples, up to 96%yield and >20:1 dr ratio). Mechanistic studies revealed that it may proceed through an uncommon β-C radical initiated 7-endo cyclization from the biradical intermediate.
文摘Essential oil from the leaves of Pistacia lentiscus L. growing in the Oran region in the west of Algeria was obtained by hydrodistillation with a 1.26 % yield on a dry weight basis. Spectrophotometric analyses were employed to highlight the scavenger capacity of this oil using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. Twenty compounds were identified by GC and CG/MS analyses, and the main part of the compounds of the oil was terpinene-4-ol (41.24%) and α-terpineol (7.31%), α-pinene (9.48%), limonene (09.11%), β-myrcene (10.5%), p-cymene (8.67%) and α-phellandrene (2.20%), β-caryophyllene (12.62%) as major compounds. The DPPH test shows that Pistacia lentiscus essential oil possesses antiradical activity. A linear correlation (correlation coefficient R<sup>2</sup> = 0.995, P Pistacia lentiscus essential oil.
基金the Qingdao Marine Science and Technology Center(No.2022QNLM030003-2)the Fundamental Research Funds for the Central Universities,Taishan Scholar Program of Shandong Province(No.tsqn201909056)+1 种基金Natural Science Foundation of Shandong Province(No.ZR2024MB122)National Natural Science Foundation of China(No.22171251)for financial support.
文摘A novel method for the asymmetric synthesis of 1,7-annulated indazoles has been developed via bifunctional Brønsted base catalyzed cascade reaction.This process enabled the formation of multiple chiral centers including a quaternary carbon center in high yields with excellent diastereoselectivities and enantioselectivities.The reaction exhibited broad functional group tolerance and mild reaction conditions.
文摘The metal coordination complex K4[Fe（CN）6] is an efficient and environmentally benign catalyst for the syn- thesis of imidazolines and benzimidazoles from various aldehydes and 1,2-diamines in aqueous medium at room temperature. This protocol gives excellent yield of product with desired purity.
基金We thank the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(QNLM)(No.2022QNLM030003-2)the Fundamental Research Funds for the Central Universities,Ocean University of China,Qingdao National Laboratory for Marine Science and Technology(Nos.LMDBCXRC201902 and LMDBCXRC201903)+2 种基金Taishan Scholar Program of Shandong Province(Nos.tsqn201909056 and tsqn202103152)National Natural Science Foundation of China(No.22171251)Natural Science Foundation of Shandong Province(No.ZR2021QB033)for financial support.
文摘A catalyst-free and atom-economical[4+3]cycloaddition of azadienes with C,N-cyclic azomethine imines has been developed,providing an efficient and environmentally benign access to 1,2,4-triazepines with high diastereoselectivities and yields.This reaction can be performed in 2-methyltetrahydrofuran under mild conditions smoothly.
基金We are thankful for financial support from OUC,QNLM(LMDBCXRC201902,LMDBCXRC201903),tsqn201909056,tsqn202103152.The project is supported by the Fundamental Research Funds for the Central Universities.
文摘A highly efficient base-mediated diastereoselective[4+1]cycloaddition of ortho-tosylaminophenyl-substituted p-QMs with 3-chlorooxindoles has been developed to afford 3,2’-pyrrolidinyl spirooxindoles in high yields with high diastereoselectivity through a domino 1,6-addition/cyclization sequence.This reaction exhibits broad substrate scope and excellent functional group tolerance.
基金We are thankful for the financial support from Ocean University of China(OUC),National Laboratory for Marine Science and Technology(QNLM)(Nos.LMDBCXRC201902,LMDBCXRC201903,tsqn201909056,tsqn202103152).The project is supported by the Fundamental Research Funds for the Central Universities.
文摘A highly efficient and environmentally benign 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with 5-alkenyl thiazolones and 2-arylidenindane-1,3-diones is developed for the construction of congested quaternary spiro-carbon centers.All these transformations can be smoothly performed in ethanol at room temperature,providing a catalyst-free and atom-economical access to diversely substituted novel isoquinoline-fused spirocycles in almost quantitative yields with high diastereoselectivities.The promising anti-tumor activity of these structurally novel spirocyclic compounds is reported as well.
基金This work was partially supported by the research council of the Iran University of Science and Technology.
文摘This study focuses on the synthesis and characterization of a novel magnetic nanocomposite 2,4,6-trihydrazino-1,3,5-triazine(THDT)-fimctionalized with silica-coated iron oxide magnetic nanoparticles(MNPs).This nanocomposite has porous morphology decorated with the spherical MNPs.Through co-precipitation of iron salts,MNPs were obtained.The prepared THDT was placed on the chlorine surface-modified MNPs.The present environment-friendly nanocatalyst intensely accelerated the synthesis of highly functionalized tetra-hydrobenzo[b]pyran derivatives as well as reduced the reaction times and increased yields of the products.
