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Colletotrin A (1), a new 1,4-benzoxazine derivative, and eight known compounds, including two alkaloids (2-3), one acylamide (4), one benzaldehyde (5), and four sterols (6-9) were obtained from endophytic fungus Colletotrichum gloeosporioides B-142, which was isolated from Dracaena cochinchinensis. Among them, 1,2,3,4-tetrahydroquinoline-4,8-diol (2) was reported for the first time as natural product. The structure of compound 1 was elucidated with help of spectroscopic data including IR, UV, electronic circular dichroism (ECD) calculation, HRESIMS, 1D and 2D NMR (COSY, HSQC and HMBC). The antimicrobial activities were evaluated by disc diffusion method. [ABSTRACT FROM AUTHOR]

A new δ-valerolactone compound, named 8-hydroxy invictolide 2 (1), a new natural product 4-hydroxy-3,5-dimethyl-6-(pentan-2-yl) tetrahydro-2H-pyran-2-one (2) together with four known compounds cyclo (L-Pro-L-Tyr) (3), cyclo (D-Pro-L-Tyr) (4), acetyltryptophan methyl ester (5), 2-aminobenzoic acid (6) were isolated from marine Streptomyces sp. YIM 13591. Their structures were elucidated by NMR spectroscopic data, HRESIMS and specific rotation, and the absolute configurations of the stereo centre in lactone ring 1 and 2 were further confirmed by electronic circular dichroism (ECD) calculation. The antimicrobial effects of these compounds were evaluated by the paper diffusion method. [ABSTRACT FROM AUTHOR]

Two new cytochalasins, deacetyl-19-epi-cytochalasin P1 (1), deacetyl-19,20-epoxycytochalasin D (2) were isolated from the endophytic fungus Diaporthe sp. RJ-47, along with four known compounds deacetyl-5,6-dihydro-7-oxo-19,20-epoxycytochalasin C (3), 19,20-epoxycytochalasin Q (4), 19,20-epoxycytochalasin C (5) and deacetyl-19,20-epoxy cytochalasin C (6). Their structures were unambiguously elucidated on the basis of the comprehensive analysis of extensive spectroscopic data. The antimicrobial effects of these compounds were evaluated. [ABSTRACT FROM AUTHOR]