The synthesis of a marine cytotoxic cyclic depsipeptide obyanamide has been accomplished. The key steps include assembling liner pentapeptide via Yamaguchi esterification and HATU-promoted ring closing. The structure ...The synthesis of a marine cytotoxic cyclic depsipeptide obyanamide has been accomplished. The key steps include assembling liner pentapeptide via Yamaguchi esterification and HATU-promoted ring closing. The structure of the synthetic sample was identified by ^1H and ^13C NMR, H-H COSY, HMQC, HMBC, and HRESIMS, but appears to be different from that of the marine natural product.展开更多
A bicyclic depsipeptide, chromopeptide A(1), was isolated from a deep-sea-derived bacterium Chromobacterium sp. HS-13-94. Its structure was determined by extensive spectroscopic analysis and by comparison with a relat...A bicyclic depsipeptide, chromopeptide A(1), was isolated from a deep-sea-derived bacterium Chromobacterium sp. HS-13-94. Its structure was determined by extensive spectroscopic analysis and by comparison with a related known compound. The absolute configuration of chromopeptide A was established by X-ray diffraction analysis employing graphite monochromated Mo K_α radiation(λ ? 0.71073 ?) with small Flack parameter 0.03. Chromopeptide A suppressed the proliferation of HL-60, K-562, and Ramos cells with average IC_(50) values of 7.7, 7.0, and 16.5 nmol/L, respectively.展开更多
By using the corresponding L-amino acid sodium as initiator,ε-caprolactone-depsipeptides CL-Ala and CL-Leu were prepared by the reactions ofε-caprolactone(CL)with L-alanine and L-leucine,respec-tively,and p-dioxanon...By using the corresponding L-amino acid sodium as initiator,ε-caprolactone-depsipeptides CL-Ala and CL-Leu were prepared by the reactions ofε-caprolactone(CL)with L-alanine and L-leucine,respec-tively,and p-dioxanone-depsipeptide(PDO-Leu)was prepared by the reaction of p-dioxanone(PDO)with L-leucine.Two poly(ε-caprolactone)oligomers(PCL-Ala and PCL-Leu)of different molecular weights with depsipeptide unit were synthesized by controlling the feed ratio of L-amino acid sodium and CL.The presence of the depsipeptide structure in these obtained products was confirmed by 1H NMR spectra and the molecular weight of the poly(ε-caprolactone)oligomers was measured by gel permeation chromatography(GPC).These products con-tain a hydroxyl group and a carboxyl group in one molecule,which means they could act as bifunctional monomers for further polymerization to prepare high molecular weight polymers.By this way,the depsipeptide unit could be introduced into the polymers and the biodegradation rates of the novel polymers could be well controlled in vivo by the tailored molecular structures.展开更多
Total synthesis of N-methylsansalvamide A was accomplished in solution phase by a convergent approach. An N-Boc-td-depsipepide 6 and a dipeptide ester 10 were prepared in the yield of 89% and 91%, respectively. Cycliz...Total synthesis of N-methylsansalvamide A was accomplished in solution phase by a convergent approach. An N-Boc-td-depsipepide 6 and a dipeptide ester 10 were prepared in the yield of 89% and 91%, respectively. Cyclization of the linear penta-depsipetide was achieved with PyBOP and DIPEA in DMF-CH2C12.展开更多
Asymmetric total synthesis of emericellamide B（9.4%, 17 longest linear steps） is detailed in this report. In this synthetic route, the highly methylated（2R,3R,4S,6S）-3-hydroxy-2,4,6-trimethyldodecanoic acid（HTMD...Asymmetric total synthesis of emericellamide B（9.4%, 17 longest linear steps） is detailed in this report. In this synthetic route, the highly methylated（2R,3R,4S,6S）-3-hydroxy-2,4,6-trimethyldodecanoic acid（HTMD） unit was effectively prepared through the asymmetric methylation, Wittig and Horner–Wadsworth–Emmons reaction. Moreover, pentafluorophenyl diphenylphophinate（FDPP） proved to be an effective condensation reagent for the macrolactamization between C14 and C18.展开更多
基金the National Natural Science Foundation of China （30572245）.
文摘The synthesis of a marine cytotoxic cyclic depsipeptide obyanamide has been accomplished. The key steps include assembling liner pentapeptide via Yamaguchi esterification and HATU-promoted ring closing. The structure of the synthetic sample was identified by ^1H and ^13C NMR, H-H COSY, HMQC, HMBC, and HRESIMS, but appears to be different from that of the marine natural product.
基金financially supported by the National Marine ‘863’ Project (Nos. 2012AA092105 and 2013AA092902)the National Natural Science Foundation of China (No. 81273430)
文摘A bicyclic depsipeptide, chromopeptide A(1), was isolated from a deep-sea-derived bacterium Chromobacterium sp. HS-13-94. Its structure was determined by extensive spectroscopic analysis and by comparison with a related known compound. The absolute configuration of chromopeptide A was established by X-ray diffraction analysis employing graphite monochromated Mo K_α radiation(λ ? 0.71073 ?) with small Flack parameter 0.03. Chromopeptide A suppressed the proliferation of HL-60, K-562, and Ramos cells with average IC_(50) values of 7.7, 7.0, and 16.5 nmol/L, respectively.
基金financially supported by Program for the New Century Excellent Talents in University“NCET”,Ministry of Education of China,and by the International Cooperation from Ministry of Science and Technology of China(Grant No.2008DFA51170)sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China.
文摘By using the corresponding L-amino acid sodium as initiator,ε-caprolactone-depsipeptides CL-Ala and CL-Leu were prepared by the reactions ofε-caprolactone(CL)with L-alanine and L-leucine,respec-tively,and p-dioxanone-depsipeptide(PDO-Leu)was prepared by the reaction of p-dioxanone(PDO)with L-leucine.Two poly(ε-caprolactone)oligomers(PCL-Ala and PCL-Leu)of different molecular weights with depsipeptide unit were synthesized by controlling the feed ratio of L-amino acid sodium and CL.The presence of the depsipeptide structure in these obtained products was confirmed by 1H NMR spectra and the molecular weight of the poly(ε-caprolactone)oligomers was measured by gel permeation chromatography(GPC).These products con-tain a hydroxyl group and a carboxyl group in one molecule,which means they could act as bifunctional monomers for further polymerization to prepare high molecular weight polymers.By this way,the depsipeptide unit could be introduced into the polymers and the biodegradation rates of the novel polymers could be well controlled in vivo by the tailored molecular structures.
基金The authors are grateful to The National Natural Science Foundation of China （No.30472074） to The Hebei province Natural Science Foundation （No.B2006000302） for financial support of this work.
文摘Total synthesis of N-methylsansalvamide A was accomplished in solution phase by a convergent approach. An N-Boc-td-depsipepide 6 and a dipeptide ester 10 were prepared in the yield of 89% and 91%, respectively. Cyclization of the linear penta-depsipetide was achieved with PyBOP and DIPEA in DMF-CH2C12.
基金the National Natural Science Foundation of China (Nos. 21472022, 21272041, 21072034)Key Laboratory for Chemical Biology of Fujian Province for financial support
文摘Asymmetric total synthesis of emericellamide B（9.4%, 17 longest linear steps） is detailed in this report. In this synthetic route, the highly methylated（2R,3R,4S,6S）-3-hydroxy-2,4,6-trimethyldodecanoic acid（HTMD） unit was effectively prepared through the asymmetric methylation, Wittig and Horner–Wadsworth–Emmons reaction. Moreover, pentafluorophenyl diphenylphophinate（FDPP） proved to be an effective condensation reagent for the macrolactamization between C14 and C18.
