Two new 4-methylidene containing steroids, craterol A and B, from the New Zealand two sponge association between Stelletta crater and Desmacella dendyi

New sterols from the South China Sea sponges Halichondria sp

A detailed chemical investigation of two specimen of South China Sea sponges Halichondria sp. (No. 19-XD-47 and No. 17-XD-87) have resulted in the isolation of three new sterols, namely, halichsterols A (1), B (2) and C (3), together with seven related known ones (4-10). Their structures were determined by extensive spectroscopic analysis and by comparison with the spectral data reported in the literature. In bioassay, compound 2 displayed significantly anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells.

Marine natural products

This review covers the literature published in 2019 for marine natural products (MNPs), with 719 citations (701 for the period January to December 2019) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1490 in 440 papers for 2019), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. Methods used to study marine fungi and their chemical diversity have also been discussed.

Four new polyhydroxylated steroids from the South Sea sponge Plakortis sp

Four new polyhydroxylated steroids plaksterols A-D (1-4), together with two known related steroids ergost-7,9(11),22-trien-3β,5α,6α-triol (5) and ergosta-6β-methoxy-7,22-diene-3β,5α-diol (6), were isolated from methanol extract of the South China Sea marine sponge Plakortis sp. Their structures were identified by spectroscopic analysis, including NMR, MS, and IR. The cytotoxicity of the polyhydroxylated steroids were evaluated, and compound 6 showed moderate inhibitory activities against K562, HL-60 and BEL-7402 cells.