Amiaspochalasins A-H, undescribed aspochalasins with a C-21 ester carbonyl from Aspergillus micronesiensis.

Amiaspochalasins A-H, undescribed aspochalasins with a C-21 ester carbonyl from Aspergillus micronesiensis.

J Org Chem. 2019 Apr 18;:

Authors: Wu Z, Zhang X, Al Anbari WH, Zhang M, Chen X, Luo Z, Li XN, Chen C, Liu J, Wang J, Zhu H, Zhang Y

Abstract
Amiaspochalasins A-H (1-8), eight undescribed aspochalasins, and trichalasin D (9), a known analogue, were isolated from the solid culture of Aspergillus micronesiensis. Compounds 1-9 are aspochalasins with a C-21 ester carbonyl, their structures were determined by spectroscopic data, X-ray crystallographic analyses, electronic circular dichroism (ECD) calculations, and chemical methods. The CH3-25 in compound 1 is located at C-16 rather than C-14 in the previously reported aspochalasins, endowing 1 with an unexpected carbon skeleton. Compounds 2 and 3 are the first examples of aspochalasins with an unprecedented 5/6/6/8 tetracyclic ring system. Compounds 4 and 5 are diastereomers of aspochalasins I and J, respectively. Compounds 6 and 7 are the first aspochalasins featuring a long open-chain system, and their absolute configurations were discussed by comparing the NMR data of the hydrolysis and methyl esterification products of 4 and 5. Compound 8 is an isomeride of 9. The cytotoxic and antimicrobial effects of 1-9 were tested.

PMID: 30997804 [PubMed – as supplied by publisher]

Source: Industry