Total Synthesis of Leptochartamides A and B: Two Enantiomeric Pairs of Hydroxybenzyl Dimers from a Deep-Sea Fungus Leptosphaerulina chartarum

Exploring the bioactive potential of deep-sea microorganisms: A review of recent discoveries

The deep-sea ecosystem, one of the most extreme and underexplored environments, harbors a remarkable diversity of microorganisms capable of producing bioactive compounds with immense pharmaceutical potential. Deep-sea microorganisms, inhabiting depths beyond 100 m, have emerged as a particularly promising source of novel bioactive compounds due to their adaptation to extreme conditions such as high pressure, low temperatures, and absence of light. This review highlights recent advancements in the discovery and characterization of 440 novel natural products from deep-sea organisms (100-11,000 m) between 2020 and October 2024. It encompasses a diverse range of deep-sea fungi and actinomycetes, detailing their source organisms, collection depths, and geographic origins. Remarkably, 80 % of these compounds exhibit bioactivity, with nearly half demonstrating potent cytotoxicity at low micromolar concentrations against various human cancer cell lines. Despite the vast majority of deep-sea microbes remaining unexplored, their potential to yield unique natural products is immense. This review succinctly presents these discoveries, emphasizing their potential biological applications and underscoring the deep-sea as a frontier for future pharmaceutical research.

New Phthalides and Isochromanone Derivatives from the Deep-Sea-Derived Fungus Penicillium bialowiezense A3

Two new phthalide derivatives, namely bialowalides A (1) and B (8), and one new isochromanone analogue biourgalide C (11), together with 8 known phthalides (2-7, 9, and 10) as well as two known isochromanones (12 and 13) were discovered from the EtOAc extract of the deep-sea-derived fungus Penicillium bialowiezense A3. The structures were resolved on the basis of extensive spectroscopic analyses (NMR and HRESIMS data), in association with the modified Mosher's method and ECD data for the determination of the absolute configurations. All isolated secondary metabolites (1-13) were tested their antiviral activities against the SARS-CoV-2 trVLP pseudovirus at a concentration of 25 μM. As a result, compounds 1, 5, 11, and 12 exhibited the inhibitory effects against the luminescence at 46.2 %, 39.6 %, 45.5 %, and 48.8 %, respectively.

Marine natural products

Covering: January to the end of December 2022This review covers the literature published in 2022 for marine natural products (MNPs), with 645 citations (633 for the period January to December 2022) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, the submerged parts of mangroves and other intertidal plants. The emphasis is on new compounds (1417 in 384 papers for 2022), 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 NP structure class diversity in relation to biota source and biome is discussed.

Hot off the Press

A personal selection of 32 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as hyjapone A from Hypericum japonicum.