New Metabolites from the South China Sea Sponge Diacarnus megaspinorhabdosa

Cyclic peroxides and analogs: Antibacterial, antimalarial, and cytotoxic marine products from Xisha sponge Diacarnus sp

A chemical investigation of the dichloromethane extract from the Xisha sponge Diacarnus sp. revealed seven undescribed norterpene cyclic peroxides, named diacarperoxides T-Z, and five unreported related norterpenes, named diacarnoids E-I, and eleven previously reported compounds. The structures of these isolated compounds, including their absolute configurations, were elucidated based on extensive spectroscopic analyses, electronic circular dichroism (ECD) calculations, Snatzke's method, [Rh2(OCOCF3)4]-induced ECD spectra, and modified Mosher's method. Bioassays were performed to assess the antibacterial activity against six pathogenic bacteria, cytotoxicities toward three cancer cell lines, and antimalarial activity against Plasmodium parasites. Most of the cyclic peroxides exhibited substantial antibacterial activity (MIC 1-8 μg/mL). Diacarperoxide W and nuapapuin A showed substantial antimalarial activity with IC50 values of 0.98 and 2.83 μM. Moreover, many compounds exhibited <50% cell survival rates, and IC50 values of 0.22-6.33 μM. The apoptosis assay showed that nuapapuin A induced cancer cell apoptosis in a dose-dependent manner.

Marine natural products

Covering: 2015. Previous review: Nat. Prod. Rep., 2016, 33, 382-431This review covers the literature published in 2015 for marine natural products (MNPs), with 1220 citations (792 for the period January to December 2015) 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 (1340 in 429 papers for 2015), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.