Drug Leads Derived from Japanese Marine Organisms

Marine natural products

Covering: January to December 2021This review covers the literature published in 2021 for marine natural products (MNPs), with 736 citations (724 for the period January to December 2021) 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 (1425 in 416 papers for 2021), 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. An analysis of the number of authors, their affiliations, domestic and international collection locations, focus of MNP studies, citation metrics and journal choices is discussed.

Enzyme Inhibitors from Gorgonians and Soft Corals

For decades, gorgonians and soft corals have been considered promising sources of bioactive compounds, attracting the interest of scientists from different fields. As the most abundant bioactive compounds within these organisms, terpenoids, steroids, and alkaloids have received the highest coverage in the scientific literature. However, enzyme inhibitors, a functional class of bioactive compounds with high potential for industry and biomedicine, have received much less notoriety. Thus, we revised scientific literature (1974-2022) on the field of marine natural products searching for enzyme inhibitors isolated from these taxonomic groups. In this review, we present representative enzyme inhibitors from an enzymological perspective, highlighting, when available, data on specific targets, structures, potencies, mechanisms of inhibition, and physiological roles for these molecules. As most of the characterization studies for the new inhibitors remain incomplete, we also included a methodological section presenting a general strategy to face this goal by accomplishing STRENDA (Standards for Reporting Enzymology Data) project guidelines.

Aqueous Extract of Sea Squirt (Halocynthia roretzi) with Potent Activity against Human Cancer Cells Acts Synergistically with Doxorubicin

Marine ascidian is becoming one of the main sources of an antitumor drug that has shown high bioactivity and extensive application in cancer treatment. Halocynthia roretzi, an edible marine sea squirt, has been demonstrated to have various kinds of biological activities, such as anti-diabetic, anti-hypertension, and enhancing immunity. In this study, we reported that aqueous extracts from the edible parts of H. roretzi presented significantly inhibiting the efficiency on HepG-2 cell viability. The separate mixed compound exhibited strong effects of inhibitory proliferation and induced apoptosis via the generation of ROS along with the concurrent loss of mitochondrial membrane potential on tumor cells. Furthermore, we found that there existed a significantly synergistic effect of the ascidian-extracted compound mixture with the anti-cancer drug doxorubicin. In the presence of the extracts from H. roretzi, the dose of doxorubicin at the cellular level could be reduced by a half dose. The extracts were further divided by semipreparative-HPLC and the active ingredients were identified as a mixture of fatty amide, which was composed of hexadecanamide, stearamide, and erucamide by UHPLC-MS/MS. Our results suggest that the potential toxicity of ascidian H. roretzi in tumor cells, and the compounds extracted from H. roretzi could be potentially utilized on functional nutraceuticals or as an adjunct in combination with chemotherapy.