Bioassay-guided fractionation of the ethanolic extract of the roots of Toddalia asiatica led to the isolation of seven new prenylated coumarins (1-7) and 14 known analogues (8-21). The structures of 1-7 were elucidated by spectroscopic analysis, and their absolute configurations were determined by combined chemical methods and chiral separation analysis. Compounds 1-5, named toddalin A, 3‴-O-demethyltoddalin A, and toddalins B-D, represent an unusual group of phenylpropenoic acid-coupled prenylated coumarins. Compounds 1-21 and four modified analogues, 10a, 11a, 13a, and 17a, were screened by using tritium-labeled adenosine 3',5'-cyclic monophosphate ([3H]-cAMP) as substrate for their inhibitory activity against phosphodiesterase-4 (PDE4), which is a drug target for the treatment of asthma and chronic obstructive pulmonary disease. Compounds 3, 8, 10, 10a, 11, 11a, 12, 13, 17, and 21 exhibited inhibition with IC50 values less than 10 μM. Toddacoumalone (8), the most active compound (IC50=0.14 μM), was more active than the positive control, rolipram (IC50=0.59 μM). In addition, the structure-activity relationship and possible inhibitory mechanism of the active compounds are also discussed.

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Eleven fumiquinazoline-type alkaloids, namely, versiquinazolines A-K (1-11), along with cottoquinazolines B-D, were isolated from the gorgonian-derived fungus Aspergillus versicolor LZD-14-1. Their structures were determined by extensive analyses of the spectroscopic data (1D and 2D NMR, HRESIMS), in addition to the experimental and calculated ECD data and X-ray single-crystal diffraction analysis for the assignments of the absolute configurations. Versiquinazolines A, B, and F (1, 2, and 6), bearing a methanediamine or an aminomethanol unit and representing a unique subtype of fumiquinazolines, were found from nature for the first time. Possible biogenetic relationships of the versiquinazolines are postulated. In addition, the structures of cottoquinazolines B (12), D (13), and C (14) should be revised to the enantiomers. Compounds 1, 2, 7, and 11 exhibited inhibitory activities against thioredoxin reductase (IC values ranging from 12 to 20 μM).

Bioassay-guided fractionation of a sponge associated fungus Stachybotrys chartarum resulted in the isolation of 15 trichothecene-based sesquiterpenes with inhibitory effects against tumor cell lines.

Bioassay-guided fractionation of the ethanolic extract of the leaves of Psidium guajava led to the isolation of 11 new Psidium meroterpenoids, psiguajadials A–K (1–11), along with 17 known ones (12–28). Their structures and absolute configurations were elucidated by spectroscopic methods and comparison of experimental and calculated ECD. Compounds 1 and 2 represent two unprecedented skeletons of 3,5-diformyl-benzyl phloroglucinol-coupled sesquiterpenoid, while 3 is the first example of Psidium meroterpenoids coupling via an oxepane ring. Putative biosynthetic pathways towards 1 and 2 are proposed. Compounds 1–13 and 16–26 exhibited moderate inhibitory activities against phosphodiesterase-4 (PDE4), a drug target for asthma and chronic obstructive pulmonary disease, with IC50 values in the range of 1.34–7.26 μM.

Chemical examination of an EtOAc extract of a cultured Acremonium sp. fungus from deep-sea sediments resulted in the isolation of 15 new eremophilane-type sesquiterpenoids, namely, acremeremophilanes A-O (1-15), together with seven known analogues. The structures of new compounds were determined through extensive spectroscopic analyses, in association with chemical conversions and ECD calculations for configurational assignments. The PKS-derived 4-hexenoic acid unit in 2-6 is rarely found in nature. All compounds were evaluated for inhibitory effects toward nitric oxide production induced by lipopolysaccharide in RAW 264.7 macrophage cells. Compounds 2-6 and 14 exhibited inhibitory effects with IC50 values ranging from 8 to 45 μM.

Versicotides D–F, new cyclopeptides were isolated from a gorgonian-derived fungusAspergillus versicolorLZD-14-1 and showed lipid-lowering effects.

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