Two cyclopeptides,heterophyllin A and B,have been isolated from the roots of Pseudostellaria heterophylla.Their structures were elucidated by chemical, spectroscopic,and enzymatic methods.
A new cyclic nonapeptide, amanexitide (1), along with the known cyclopeptides, a- and b-amanitins, was isolated from the fruiting bodies of Amanita exitialis, a newly described poisonous mushroom endemic to Guangzhou,...A new cyclic nonapeptide, amanexitide (1), along with the known cyclopeptides, a- and b-amanitins, was isolated from the fruiting bodies of Amanita exitialis, a newly described poisonous mushroom endemic to Guangzhou, Guangdong Province, China. Its amino acid composition and absolute configuration were determined by chemical degradation and derivatization followed by chiral GC analysis. Its amino acid sequence was elucidated by extensive analysis of ESIMS/MS and FTICRMS data. The occurrence of 1 in this mushroom is interesting because it has a structure closely related to antamanide, a cyclic decapeptide with antidote activity against amatoxins and phallotoxins, occurring in A. phalloides.展开更多
Two new cyclic peptides, polycarponin B and C (1, 2), were isolated from the whole plants of Polycarpon prostratum (Forssk.) Aschers. et Schwein. ex Aschers. By detailed spectroscopic analysis, their structures were d...Two new cyclic peptides, polycarponin B and C (1, 2), were isolated from the whole plants of Polycarpon prostratum (Forssk.) Aschers. et Schwein. ex Aschers. By detailed spectroscopic analysis, their structures were determined as cyclo(-Gly(1)-Ile-Val(1)-Leu(1)-Val(2)-Gly(2)-Leu(2)-Pro) and cyclo(-Pro(1)-Thr-Leu(1)-Pro(2)-Pro(3)-Val-Leu(2)-Phe), respectively.展开更多
New minor cyclic peptides, named arenariphilin C 1 and arenariphilin D 2, were isolated from the whole plants of Arenaria oreophila （Caryophyllaceae）. Their structures were determined as cyclo（Pro^1-Pro2-Leu^1-Leu2...New minor cyclic peptides, named arenariphilin C 1 and arenariphilin D 2, were isolated from the whole plants of Arenaria oreophila （Caryophyllaceae）. Their structures were determined as cyclo（Pro^1-Pro2-Leu^1-Leu2-Phe-Ser-Gly-Thr） and cyclo （Ser-Cys） on the basis of spectroscopic data, especially by two-dimension NMR （2D NMR） technologies.展开更多
Two new cyclopeptides, leiocyclocin A (1); B (2), were isolated from the seeds of Goniothalanus leiocarpus. Their structures were elucidated by means of spectral and chemical methods.
Based on the pseudo-dilution effect (PDE) on solid support, three cyclopeptides with an aliphatic-aryl ether bond as the bridge were synthesized via SN2 reaction between bromoacetylated at N-terminal and the phenol –...Based on the pseudo-dilution effect (PDE) on solid support, three cyclopeptides with an aliphatic-aryl ether bond as the bridge were synthesized via SN2 reaction between bromoacetylated at N-terminal and the phenol –OH group in C-terminal Tyr residue. All the products were obtained in good overall yields and characterized by related analytic data.展开更多
Cyclopeptides have been investigated phytochemically less often because until now there has not been a special chemical method to detect them. Since we found cyclopeptides in Pseudostellaria heterophylla (Caryophyllac...Cyclopeptides have been investigated phytochemically less often because until now there has not been a special chemical method to detect them. Since we found cyclopeptides in Pseudostellaria heterophylla (Caryophyllaceae) in 1991, we have gradually established a special chemical detection method for detecting cyclopeptides in plants, which induces a new thin layer chromatography (TLC) protosite reaction with ninhydrin reagent. With this method, our group isolated and determined 73 cyclopeptides from 17 plants which belong to 5 families and 14 genuses, they are from dicyclopeptides to undecacyclopeptides, including 68 new ones, and were determined based on spectral, chemical and enzymic methods, especially 2D NMR and FAB-MS. Meantime, with this method cyclopeptides can be distinguished from peptidic amides based on their behaviour in TLC.展开更多
In the previous papers, we reported the isolation and structural elucidation of three new cyclopeptides, namely stellarin A, B and C, from the fresh roots of stellaria yunnanensis Franch. In a continued study on this ...In the previous papers, we reported the isolation and structural elucidation of three new cyclopeptides, namely stellarin A, B and C, from the fresh roots of stellaria yunnanensis Franch. In a continued study on this plant, other two new cyclopeptides named stellarin D(1) and E(2) were obtained and their structures were established to be cyclo (Gly-Tyr-Leu-Phe-Pro-Ile-Pro)(1), cyclo(Gly-Ile-Pro-Tyr-Ile-Ala-Ala)(2), respectively.展开更多
In the previous papers, we reported the structural elucidation of stellarins A-E, five new cyclopeptides from the fresh roots of Stellaria yunnanensis Franch. Further chemical study on this plant led to the isolation ...In the previous papers, we reported the structural elucidation of stellarins A-E, five new cyclopeptides from the fresh roots of Stellaria yunnanensis Franch. Further chemical study on this plant led to the isolation of two other new cyclopeptide named stellarins F(1) and G(2). By a combination of 2D-NMR, enzymatic degradation and FABMS, their structures were established to by cyclo(Gly-Ala-Gly-Ser-Pro-Trp-Phe-Pro) and cyclo(Gly-Ala-Tyr-Leu-Ala), respectively.展开更多
Two new cyclopeptides, nagitides A and B, were isolated from the stem bark ofPodoearpus nagi. Their struc- tures were elucidated on the basis of NMR experiments including IH-IH COSY, HSQC, HMBC, ROESY, etc. This is th...Two new cyclopeptides, nagitides A and B, were isolated from the stem bark ofPodoearpus nagi. Their struc- tures were elucidated on the basis of NMR experiments including IH-IH COSY, HSQC, HMBC, ROESY, etc. This is the first report of cyclopeptides separated from this plant.展开更多
TAG-assisted peptide synthesis technology enables optimal conservation of Fmoc amino acid raw materials and chemical solvents while eliminating the need for intricate chromatographic purification processes.This work p...TAG-assisted peptide synthesis technology enables optimal conservation of Fmoc amino acid raw materials and chemical solvents while eliminating the need for intricate chromatographic purification processes.This work presents a 4,4'-diphenylphosphonoxy diphenylcarbinol tag-mediated liquid-phase synthesis approach for preparing side-to-tail cyclopeptides macolacin which has strong activity against gram-negative bacteria,and its 15 analogues containing four N-methylation modified cyclopeptides,as well as an investigation of their structure-activity relationship(SAR).The synthesis of macolacin analogues primarily focuses on the modifications of the N-methylation group of Ile-7 and the tail fatty acyl chain of macolacin.The incorporation of N-methylation for Ile-7,along with the dihalogenated or monohalogenated benzoic acids for tail modification,exhibited remarkable antibacterial efficacy and minimal hepatocellular toxicity in vitro.The present study identified an N-methylation-modified antimicrobial cyclopeptide Ma14 that exhibits rapid bactericidal efficacy against A.baumanii,etc.,while showing reduced hepatocellular toxicity.Molecular docking simulations were conducted to investigate the binding of cyclopeptides to the outer membrane protein BamA of A.baumannii.The findings demonstrated the stable binding interactions of the cyclopeptides with the BamA protein and then presented a novel approach to explain the bacteriostatic mechanism of macolacin-based cyclopeptide antibiotics.展开更多
Two cyclopeptides, celogentin L(1) and its epimer lyciumin A(2) were firstly isolated from Celosia argentea L.. The planar structures of the two compounds were fully determined by spectroscopic data, including 1 D-, 2...Two cyclopeptides, celogentin L(1) and its epimer lyciumin A(2) were firstly isolated from Celosia argentea L.. The planar structures of the two compounds were fully determined by spectroscopic data, including 1 D-, 2 D-NMR, and HR-ESI/MS. The absolute configurations of amino acid components were assigned via chiral-phase HPLC analyses after acid hydrolysis. Furthermore, the configuration of C-N linkage at the glycine Cα was elucidated by extensive analyses of 2 D-NMR and comparison of the experimental and calculated electronic circular dichroism(ECD) spectra. Cytotoxicity of the two compounds against human alveolar epithelial A549, hepatocellular carcinoma Hep G2, and cervical cancer Hela cell lines was assayed. Although both of them were inactive in these cells, the present findings add new facets for the chemistry of Celosia argentea.展开更多
The conformation of cyclodecapeptide loloatin C with obvious antibiotic activity has been investigated in 2,2,2-trifluoroethanol/sodium acetate buffer solution and then characterized by FT-IR, CD and NMR spectrum. T...The conformation of cyclodecapeptide loloatin C with obvious antibiotic activity has been investigated in 2,2,2-trifluoroethanol/sodium acetate buffer solution and then characterized by FT-IR, CD and NMR spectrum. The results of FT-IR show that there exists β-strand or β-turn secondary structure in the molecule. According to the CD spectrum, the helical turn is dominant but the β-turn structure also exists. Conformation of the whole molecule is probably a helical β-turn. The chemical shifts and coupling constants prove the existence of a β-structure in the regions of Val1, Orn2 and Leu3. NOESY data and temperature gradients of amide protons suggest that the molecular conformation is a dumbbell-like structure with the waist located between ornithyl (position 2) and D-phenylalanyl (position 7) and β-turn on both ends.展开更多
Two new cyclic nonapeptides,named clausenlanins A(1)and B(2),were isolated from the roots and rhizomes of Clausena lansium.Their structures were elucidated as cyclo-(Gly^(1)-L-Leu^(2)-L-Ile^(3)-L-Leu^(4)-L-Leu^(5)-L-L...Two new cyclic nonapeptides,named clausenlanins A(1)and B(2),were isolated from the roots and rhizomes of Clausena lansium.Their structures were elucidated as cyclo-(Gly^(1)-L-Leu^(2)-L-Ile^(3)-L-Leu^(4)-L-Leu^(5)-L-Leu^(6)-L-Leu^(7)-L-Leu^(8)-L-Leu^(9))(1)and cyclo-(Gly^(1)-L-Leu^(2)-L-Val^(3)-L-Leu^(4)-L-Leu^(5)-L-Leu^(6)-L-Leu^(7)-L-Leu^(8)-L-Leu^(9))(2)respectively on the basis of extensive spectroscopic analysis,particularly 2D NMR spectra taken at the temperature of 338 or 303 K and MS.展开更多
A new cyclic octapeptide (schnabepeptide B) was isolated from the aerial part of Schnabelia tetradonta (Sun) C. Y. Wu et C. Chen (Lamiaceae). Its structure was elucidated as cyclo-(NH-Trp-Gly1-Leu1-Gly2-Pro1-Pro2-Leu2...A new cyclic octapeptide (schnabepeptide B) was isolated from the aerial part of Schnabelia tetradonta (Sun) C. Y. Wu et C. Chen (Lamiaceae). Its structure was elucidated as cyclo-(NH-Trp-Gly1-Leu1-Gly2-Pro1-Pro2-Leu2-Pro3-CO) on the basis of extensive 2D NMR and MS spectra.展开更多
A chemical investigation on the cultures of Xylaria carpophila led to the isolation of one known cyclopeptide cyclo(N-methyl-L-Phe-L-Pro-L-Leu-D-Ile-L-Val)(1),five new sesquiterpenes,named as xylcarpins A-E(2-6),and a...A chemical investigation on the cultures of Xylaria carpophila led to the isolation of one known cyclopeptide cyclo(N-methyl-L-Phe-L-Pro-L-Leu-D-Ile-L-Val)(1),five new sesquiterpenes,named as xylcarpins A-E(2-6),and another known compound(7).The structures were determined by extensive NMR and MS spectroscopic analysis.The absolute configuration of 1 was established by use of Marfey’s method and ROESY spectroscopic data.All compounds were tested for their cytotoxicities against five human cancer cell lines.Compound 7 showed week inhibitory activity.展开更多
A new cyclic peptide named polycarponin A, was isolated from the whole plants of Polycarpon prostratum. Its structure was determined by detailed spectroscopic analysis.
A new cyclopeptide as well as a known cyclopeptide were isolated from the whole plants of Dianthus caryophyllus. Their structures were elucidated as cyclo （-Thr-Gly-Pro-Tyr-Phe-） （1） and cyclo （-Ala-Gly-Ser-IIe-P...A new cyclopeptide as well as a known cyclopeptide were isolated from the whole plants of Dianthus caryophyllus. Their structures were elucidated as cyclo （-Thr-Gly-Pro-Tyr-Phe-） （1） and cyclo （-Ala-Gly-Ser-IIe-Phe-Phe-） （2） by means of chemical and spectroscopic methods including MS, 1D and 2D NMR techniques.展开更多
Phakellistatin 13 is a good antitumor lead compound isolated from halobios. It was synthesized first time by solution method in combination of stepwise coupling and segment condensation. Final deprotection and cycliza...Phakellistatin 13 is a good antitumor lead compound isolated from halobios. It was synthesized first time by solution method in combination of stepwise coupling and segment condensation. Final deprotection and cyclization were achieved according to our designed method, which was different from the reported process. The spectral data of synthetic product is consisted with literatureal data of natural product. Total synthesis of phakellistatin 13 is a significant achievement to further study of its derivatives and developing novel antitumor drugs.展开更多
文摘Two cyclopeptides,heterophyllin A and B,have been isolated from the roots of Pseudostellaria heterophylla.Their structures were elucidated by chemical, spectroscopic,and enzymatic methods.
基金This work was supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(No.KSCX2-YW-N-036).
文摘A new cyclic nonapeptide, amanexitide (1), along with the known cyclopeptides, a- and b-amanitins, was isolated from the fruiting bodies of Amanita exitialis, a newly described poisonous mushroom endemic to Guangzhou, Guangdong Province, China. Its amino acid composition and absolute configuration were determined by chemical degradation and derivatization followed by chiral GC analysis. Its amino acid sequence was elucidated by extensive analysis of ESIMS/MS and FTICRMS data. The occurrence of 1 in this mushroom is interesting because it has a structure closely related to antamanide, a cyclic decapeptide with antidote activity against amatoxins and phallotoxins, occurring in A. phalloides.
文摘Two new cyclic peptides, polycarponin B and C (1, 2), were isolated from the whole plants of Polycarpon prostratum (Forssk.) Aschers. et Schwein. ex Aschers. By detailed spectroscopic analysis, their structures were determined as cyclo(-Gly(1)-Ile-Val(1)-Leu(1)-Val(2)-Gly(2)-Leu(2)-Pro) and cyclo(-Pro(1)-Thr-Leu(1)-Pro(2)-Pro(3)-Val-Leu(2)-Phe), respectively.
文摘New minor cyclic peptides, named arenariphilin C 1 and arenariphilin D 2, were isolated from the whole plants of Arenaria oreophila （Caryophyllaceae）. Their structures were determined as cyclo（Pro^1-Pro2-Leu^1-Leu2-Phe-Ser-Gly-Thr） and cyclo （Ser-Cys） on the basis of spectroscopic data, especially by two-dimension NMR （2D NMR） technologies.
基金This work was supported by the National Natural Science Foundation of China(Grant No.39770089)the Applied and Basic Rcscarch Foundation of Yunnan province(Grant No.97B038q).
文摘Two new cyclopeptides, leiocyclocin A (1); B (2), were isolated from the seeds of Goniothalanus leiocarpus. Their structures were elucidated by means of spectral and chemical methods.
文摘Based on the pseudo-dilution effect (PDE) on solid support, three cyclopeptides with an aliphatic-aryl ether bond as the bridge were synthesized via SN2 reaction between bromoacetylated at N-terminal and the phenol –OH group in C-terminal Tyr residue. All the products were obtained in good overall yields and characterized by related analytic data.
文摘Cyclopeptides have been investigated phytochemically less often because until now there has not been a special chemical method to detect them. Since we found cyclopeptides in Pseudostellaria heterophylla (Caryophyllaceae) in 1991, we have gradually established a special chemical detection method for detecting cyclopeptides in plants, which induces a new thin layer chromatography (TLC) protosite reaction with ninhydrin reagent. With this method, our group isolated and determined 73 cyclopeptides from 17 plants which belong to 5 families and 14 genuses, they are from dicyclopeptides to undecacyclopeptides, including 68 new ones, and were determined based on spectral, chemical and enzymic methods, especially 2D NMR and FAB-MS. Meantime, with this method cyclopeptides can be distinguished from peptidic amides based on their behaviour in TLC.
基金Project supported by grants from Laboratory of Phytochemistry Kunming Institute of Botany, Chinese Academy of Sciences and State Key Laboratory of Bio-organic & Natural Products Chemistry,Shanghai Institute of Organic Chemistry,Chinese Academy of Science
文摘In the previous papers, we reported the isolation and structural elucidation of three new cyclopeptides, namely stellarin A, B and C, from the fresh roots of stellaria yunnanensis Franch. In a continued study on this plant, other two new cyclopeptides named stellarin D(1) and E(2) were obtained and their structures were established to be cyclo (Gly-Tyr-Leu-Phe-Pro-Ile-Pro)(1), cyclo(Gly-Ile-Pro-Tyr-Ile-Ala-Ala)(2), respectively.
基金Project supproted by grants from Laboratory of Phytochemistry,Kunming Institute of Botany,Chinese Academy of Sciences and State Key Laboratory of Bio-Organic Chemistry & Natural Products,Chinese Academy of Sciences.
文摘In the previous papers, we reported the structural elucidation of stellarins A-E, five new cyclopeptides from the fresh roots of Stellaria yunnanensis Franch. Further chemical study on this plant led to the isolation of two other new cyclopeptide named stellarins F(1) and G(2). By a combination of 2D-NMR, enzymatic degradation and FABMS, their structures were established to by cyclo(Gly-Ala-Gly-Ser-Pro-Trp-Phe-Pro) and cyclo(Gly-Ala-Tyr-Leu-Ala), respectively.
文摘Two new cyclopeptides, nagitides A and B, were isolated from the stem bark ofPodoearpus nagi. Their struc- tures were elucidated on the basis of NMR experiments including IH-IH COSY, HSQC, HMBC, ROESY, etc. This is the first report of cyclopeptides separated from this plant.
基金supported by the Shanxi Provincial Key Research and Development Project(202102130501004).
文摘TAG-assisted peptide synthesis technology enables optimal conservation of Fmoc amino acid raw materials and chemical solvents while eliminating the need for intricate chromatographic purification processes.This work presents a 4,4'-diphenylphosphonoxy diphenylcarbinol tag-mediated liquid-phase synthesis approach for preparing side-to-tail cyclopeptides macolacin which has strong activity against gram-negative bacteria,and its 15 analogues containing four N-methylation modified cyclopeptides,as well as an investigation of their structure-activity relationship(SAR).The synthesis of macolacin analogues primarily focuses on the modifications of the N-methylation group of Ile-7 and the tail fatty acyl chain of macolacin.The incorporation of N-methylation for Ile-7,along with the dihalogenated or monohalogenated benzoic acids for tail modification,exhibited remarkable antibacterial efficacy and minimal hepatocellular toxicity in vitro.The present study identified an N-methylation-modified antimicrobial cyclopeptide Ma14 that exhibits rapid bactericidal efficacy against A.baumanii,etc.,while showing reduced hepatocellular toxicity.Molecular docking simulations were conducted to investigate the binding of cyclopeptides to the outer membrane protein BamA of A.baumannii.The findings demonstrated the stable binding interactions of the cyclopeptides with the BamA protein and then presented a novel approach to explain the bacteriostatic mechanism of macolacin-based cyclopeptide antibiotics.
基金financially supported by the National Natural Science Foundation of China(Nos.81322051 and 31400300)the Natural Science Foundation of Jiangsu Province(No.BK20151442)the Project Funded by the Priority Academic Program Development(PAPD) of Jiangsu Higher Education Institutions
文摘Two cyclopeptides, celogentin L(1) and its epimer lyciumin A(2) were firstly isolated from Celosia argentea L.. The planar structures of the two compounds were fully determined by spectroscopic data, including 1 D-, 2 D-NMR, and HR-ESI/MS. The absolute configurations of amino acid components were assigned via chiral-phase HPLC analyses after acid hydrolysis. Furthermore, the configuration of C-N linkage at the glycine Cα was elucidated by extensive analyses of 2 D-NMR and comparison of the experimental and calculated electronic circular dichroism(ECD) spectra. Cytotoxicity of the two compounds against human alveolar epithelial A549, hepatocellular carcinoma Hep G2, and cervical cancer Hela cell lines was assayed. Although both of them were inactive in these cells, the present findings add new facets for the chemistry of Celosia argentea.
文摘The conformation of cyclodecapeptide loloatin C with obvious antibiotic activity has been investigated in 2,2,2-trifluoroethanol/sodium acetate buffer solution and then characterized by FT-IR, CD and NMR spectrum. The results of FT-IR show that there exists β-strand or β-turn secondary structure in the molecule. According to the CD spectrum, the helical turn is dominant but the β-turn structure also exists. Conformation of the whole molecule is probably a helical β-turn. The chemical shifts and coupling constants prove the existence of a β-structure in the regions of Val1, Orn2 and Leu3. NOESY data and temperature gradients of amide protons suggest that the molecular conformation is a dumbbell-like structure with the waist located between ornithyl (position 2) and D-phenylalanyl (position 7) and β-turn on both ends.
基金the Program for Jiangsu Province Innovative Research Team,the National Basic Research Program of China(2013CB127505)the National Natural Science Foundation of China(31470428)+1 种基金the Project of State Key Laboratory of Natural Medicines(SKLNMZZCX201614)the Foundation of High-level Talent Introduction of China Pharmaceutical University.We are grateful to Prof.Yu-Min Shui(Kunming Institute of Botany,CAS)for identification of the material.
文摘Two new cyclic nonapeptides,named clausenlanins A(1)and B(2),were isolated from the roots and rhizomes of Clausena lansium.Their structures were elucidated as cyclo-(Gly^(1)-L-Leu^(2)-L-Ile^(3)-L-Leu^(4)-L-Leu^(5)-L-Leu^(6)-L-Leu^(7)-L-Leu^(8)-L-Leu^(9))(1)and cyclo-(Gly^(1)-L-Leu^(2)-L-Val^(3)-L-Leu^(4)-L-Leu^(5)-L-Leu^(6)-L-Leu^(7)-L-Leu^(8)-L-Leu^(9))(2)respectively on the basis of extensive spectroscopic analysis,particularly 2D NMR spectra taken at the temperature of 338 or 303 K and MS.
基金This research was supported by the grant from the Special Project of Biological Science and Technology of the Chinese Academy of Sciences(STZ 97-3-08).
文摘A new cyclic octapeptide (schnabepeptide B) was isolated from the aerial part of Schnabelia tetradonta (Sun) C. Y. Wu et C. Chen (Lamiaceae). Its structure was elucidated as cyclo-(NH-Trp-Gly1-Leu1-Gly2-Pro1-Pro2-Leu2-Pro3-CO) on the basis of extensive 2D NMR and MS spectra.
基金This project was supported by the National Basic Research Program of China(973 Program,2009CB522300)the National Natural Sciences Foundation of China(30830113)MOST(2009ZX09501-029).
文摘A chemical investigation on the cultures of Xylaria carpophila led to the isolation of one known cyclopeptide cyclo(N-methyl-L-Phe-L-Pro-L-Leu-D-Ile-L-Val)(1),five new sesquiterpenes,named as xylcarpins A-E(2-6),and another known compound(7).The structures were determined by extensive NMR and MS spectroscopic analysis.The absolute configuration of 1 was established by use of Marfey’s method and ROESY spectroscopic data.All compounds were tested for their cytotoxicities against five human cancer cell lines.Compound 7 showed week inhibitory activity.
文摘A new cyclic peptide named polycarponin A, was isolated from the whole plants of Polycarpon prostratum. Its structure was determined by detailed spectroscopic analysis.
基金supported by the Natural Science Foundation of Ynunan Province(No.2007B021M)Yurman University(No.2003Q008A).
文摘A new cyclopeptide as well as a known cyclopeptide were isolated from the whole plants of Dianthus caryophyllus. Their structures were elucidated as cyclo （-Thr-Gly-Pro-Tyr-Phe-） （1） and cyclo （-Ala-Gly-Ser-IIe-Phe-Phe-） （2） by means of chemical and spectroscopic methods including MS, 1D and 2D NMR techniques.
文摘Phakellistatin 13 is a good antitumor lead compound isolated from halobios. It was synthesized first time by solution method in combination of stepwise coupling and segment condensation. Final deprotection and cyclization were achieved according to our designed method, which was different from the reported process. The spectral data of synthetic product is consisted with literatureal data of natural product. Total synthesis of phakellistatin 13 is a significant achievement to further study of its derivatives and developing novel antitumor drugs.
