Cangumycins A-F(1–6), six new angucyclinone analogues, together with two known ones(7 and 8), were isolated from the fermentation broth of a soil-derived Streptomyces sp. KIB-M10. Structures of these compounds were e...Cangumycins A-F(1–6), six new angucyclinone analogues, together with two known ones(7 and 8), were isolated from the fermentation broth of a soil-derived Streptomyces sp. KIB-M10. Structures of these compounds were elucidated via a joint use of spectroscopic analyses and single-crystal X-ray diffractions. Among them, cangumycins E(5) and F(6) share a C-ring cleaved backbone, and cangumycins B(2) and E(5) exhibit potent immunosuppressive activity(IC50 8.1 and 2.7 μmol·L^-1, respectively) against human T cell proliferation at a non-cytotoxic concentration.展开更多
Angucyclinones are aromatic polyketides produced by type Ⅱ polyketide synthases（PKS） and are mainly found in terrestrial actinomycetes. To discover more angucyclinones from marine actinomycetes, a genomic DNA-based...Angucyclinones are aromatic polyketides produced by type Ⅱ polyketide synthases（PKS） and are mainly found in terrestrial actinomycetes. To discover more angucyclinones from marine actinomycetes, a genomic DNA-based PCR assay targeting type Ⅱ polyketide synthases was performed. Among the 167 marine actinomycetes strains screened, twelve strains were identified as the ＂positive＂ strains possessing type Ⅱ PKS-encoding genes based on the sequencing of PCR products. One of the 12 ＂positive＂ strains, Streptomyces sp. PKU-MA00218 was selected for the large-scale fermentation based on the HPLC and TLC analysis. Four angucyclinones, 6-deoxy-8-O-methylrabelomycin（1）, 8-O-methylrabelomycin（2）, 8-O-methyltetrangulol（3）, C-ring cleavage product of angucyclinone C（4）, were isolated and their structures were elucidated based on spectroscopic analyses. The isolation of angucyclinones 1–4 highlights the power of genome mining technologies based on biosynthetic knowledge in natural products discovery.展开更多
Nine bioactive ochromycinone analogues were synthesized through two different types of routes. Some unexpected products were obtained in the photo-induced oxidation. The syntheses disclosed herein complement those in ...Nine bioactive ochromycinone analogues were synthesized through two different types of routes. Some unexpected products were obtained in the photo-induced oxidation. The syntheses disclosed herein complement those in the literature and offer inexpensive access to many of the known intermediates involved, most of which were studied years ago in completely different contexts.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U1702285 and 81522044)Natural Science Foundation of Yunnan Province(No.2016FA003)+1 种基金the State key laboratory of phytochemistry and plant resource in west China(No.P2018-KF03)Key Research Program of Frontier Sciences and the Strategic Priority Research Program,CAS(Nos.QYZDB-SSW-SMC051 and XDB27020205)
文摘Cangumycins A-F(1–6), six new angucyclinone analogues, together with two known ones(7 and 8), were isolated from the fermentation broth of a soil-derived Streptomyces sp. KIB-M10. Structures of these compounds were elucidated via a joint use of spectroscopic analyses and single-crystal X-ray diffractions. Among them, cangumycins E(5) and F(6) share a C-ring cleaved backbone, and cangumycins B(2) and E(5) exhibit potent immunosuppressive activity(IC50 8.1 and 2.7 μmol·L^-1, respectively) against human T cell proliferation at a non-cytotoxic concentration.
基金National Natural Science Foundation of China(Grant No.81573326)
文摘Angucyclinones are aromatic polyketides produced by type Ⅱ polyketide synthases（PKS） and are mainly found in terrestrial actinomycetes. To discover more angucyclinones from marine actinomycetes, a genomic DNA-based PCR assay targeting type Ⅱ polyketide synthases was performed. Among the 167 marine actinomycetes strains screened, twelve strains were identified as the ＂positive＂ strains possessing type Ⅱ PKS-encoding genes based on the sequencing of PCR products. One of the 12 ＂positive＂ strains, Streptomyces sp. PKU-MA00218 was selected for the large-scale fermentation based on the HPLC and TLC analysis. Four angucyclinones, 6-deoxy-8-O-methylrabelomycin（1）, 8-O-methylrabelomycin（2）, 8-O-methyltetrangulol（3）, C-ring cleavage product of angucyclinone C（4）, were isolated and their structures were elucidated based on spectroscopic analyses. The isolation of angucyclinones 1–4 highlights the power of genome mining technologies based on biosynthetic knowledge in natural products discovery.
基金Project supported by the National Natural Science Foundation of China （Nos of Sciences （No. KGCX2-SW-209）. Dedicated to Professor Xikui Jiang on the occasion of his 80th birthday 20025207, 20272071, 20372075, 20321202） and the Chinese Academy
文摘Nine bioactive ochromycinone analogues were synthesized through two different types of routes. Some unexpected products were obtained in the photo-induced oxidation. The syntheses disclosed herein complement those in the literature and offer inexpensive access to many of the known intermediates involved, most of which were studied years ago in completely different contexts.
