New compounds from a hydrothermal vent crab-associated fungus Aspergillus versicolor XZ-4. Issue 5 (11th January 2017)

• Record Type: Journal Article
• Authors: Pan, Chengqian; Shi, Yutong; Chen, Xuegang; Chen, Chen-Tung Arthur; Tao, Xinyi; Wu, Bin
• Is Part Of: Organic & biomolecular chemistry. Volume 15:Issue 5(2017)
• Page Start: 1155
• Page End: 1163
• Publication Date: 2017-01-11
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c6ob02374f
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : Three new quinazoline derivatives (1–3 ), one new oxepin-containing natural product (4 ) and four new cyclopenin derivatives (5–7 and9 ) have been isolated from an EtOAc extract of the Taiwan Kueishantao hydrothermal vent crab-associated fungus Aspergillus versicolor XZ-4. Abstract : Three new quinazoline derivatives (1–3 ), one new oxepin-containing natural product (4 ) and four new cyclopenin derivatives (5–7 and9 ) have been isolated from an EtOAc extract of the Taiwan Kueishantao hydrothermal vent crab-associated fungus Aspergillus versicolor XZ-4. Their planar structures were established by HRMS, 1D and 2D NMR spectroscopic data analyses. The absolute configurations for compounds1 and4 were determined by chiral phase HPLC analysis of their hydrolysis products. The absolute configurations of2, 3 and7 were defined mainly by comparison of the quantum chemical TDDFT calculated and the experimental ECD spectra, and the absolute configuration of5 was deduced from comparison of the optical rotation values reported in the literature. The presence of two atropisomers of5 was established by NOE analyses. The Ile & Val units in compounds1–3 allowed the assignment of a new quinazoline skeleton and it's the first time the configuration of isoleucine in the quinazoline skeleton was defined. A series of 7-methoxy cyclopenin derivatives were reported for the first time in this study. The bioevaluation of compounds5, 7, 8 and9 revealed inhibitory activities against E. coli at MIC values around 32 μg mL −1 .