(+)- and (-)-Ascomlactone A: a pair of novel dimeric polyketides from a mangrove endophytic fungus Ascomycota sp. SK2YWS-L.

A pair of novel enantiomeric polyketide dimers, (+)- and (-)-ascomlactone A (1a and 1b), were obtained from a mangrove endophytic fungus Ascomycota sp. SK2YWS-L. The structures were elucidated based on spectroscopic methods, and the absolute configurations were determined by X-ray diffraction and electronic circular dichroism (ECD) calculations.

A new α-pyrone from the mangrove endophytic fungus Phomopsis sp. HNY29-2B.

A new α-pyrone derivative, phomopyrone A (1), together with two known compounds (2-3), was isolated from the culture of the mangrove endophytic fungus Phomopsis sp. HNY29-2B. Their structures were determined by detailed analysis of spectroscopic data.

Cantharimide and Its Derivatives from the Blister Beetle Mylabris phalerata Palla.

Eleven new monoterpenoids including three 1-methyl cantharimide-type derivatives (1-3), five 1,2-dimethyl cantharimide-type derivatives (4, 5, 7-9), and three 1-hydroxymethyl-2-methyl cantharimide-type derivatives (10-12), together with seven known cantharimides (6, 13-18), were isolated from Mylabis phalerata Palla. The planar structures and absolute configurations of compounds 1-14 were fully elucidated on the basis of spectroscopic analysis, ECD spectra, single-crystal X-ray diffraction analysis, and chemical methods. Compounds 6, 15, 16, and 18 were found to be potent inhibitors of HBV virus, with IC50 values of 62, 42, 58, and 19 μM.

Asperlones A and B, dinaphthalenone derivatives from a mangrove endophytic fungus Aspergillus sp. 16-5C.

Racemic dinaphthalenone derivatives, (±)-asperlone A (1) and (±)-asperlone B (2), and two new azaphilones, 6'-hydroxy-(R)-mitorubrinic acid (3) and purpurquinone D (4), along with four known compounds, (-)-mitorubrinic acid (5), (-)-mitorubrin (6), purpurquinone A (7) and orsellinic acid (8), were isolated from the cultures of Aspergillus sp. 16-5C. The structures were elucidated using comprehensive spectroscopic methods, including 1D and 2D NMR spectra and the structures of 1 further confirmed by single-crystal X-ray diffraction analysis, while the absolute configuration of 3 and 4 were determined by comparing their optical rotation and CD with those of the literature, respectively.