New tridecapeptides of the theonellapeptolide family from the Indonesian sponge Theonella swinhoei

Chemical Diversity and Biological Activity of Secondary Metabolites Isolated from Indonesian Marine Invertebrates

Marine invertebrates have been reported to be an excellent resource of many novel bioactive compounds. Studies reported that Indonesia has remarkable yet underexplored marine natural products, with a high chemical diversity and a broad spectrum of biological activities. This review discusses recent updates on the exploration of marine natural products from Indonesian marine invertebrates (i.e., sponges, tunicates, and soft corals) throughout 2007-2020. This paper summarizes the structural diversity and biological function of the bioactive compounds isolated from Indonesian marine invertebrates as antimicrobial, antifungal, anticancer, and antiviral, while also presenting the opportunity for further investigation of novel compounds derived from Indonesian marine invertebrates.

Marine Natural Products from Indonesian Waters

Natural products are primal and have been a driver in the evolution of organic chemistry and ultimately in science. The chemical structures obtained from marine organisms are diverse, reflecting biodiversity of genes, species and ecosystems. Biodiversity is an extraordinary feature of life and provides benefits to humanity while promoting the importance of environment conservation. This review covers the literature on marine natural products (MNPs) discovered in Indonesian waters published from January 1970 to December 2017, and includes 732 original MNPs, 4 structures isolated for the first time but known to be synthetic entities, 34 structural revisions, 9 artifacts, and 4 proposed MNPs. Indonesian MNPs were found in 270 papers from 94 species, 106 genera, 64 families, 32 orders, 14 classes, 10 phyla, and 5 kingdoms. The emphasis is placed on the structures of organic molecules (original and revised), relevant biological activities, structure elucidation, chemical ecology aspects, biosynthesis, and bioorganic studies. Through the synthesis of past and future data, huge and partly undescribed biodiversity of marine tropical invertebrates and their importance for crucial societal benefits should greatly be appreciated.

Lanesoic Acid: A Cytotoxic Zwitterion from Theonella sp

Lanesoic acid (1) was isolated and characterized from Theonella sp. during PharmaMar's ongoing program to study cytotoxic substances from marine sources. Its planar structure, elucidated by spectral analysis (NMR, IR, UV, and MS), possesses an unusual skeleton containing a tetrahydropyrimidine cation that is stabilized as a zwitterion by an internal carboxylate counterion. The stereostructure of 1 was deduced from ROESY-NOESY, J-based configurational analysis (JBCA), and density functional theory (DFT) computational calculations fitted using the recently published DP4+ parameter. Compound 1 was moderately active and selective against pancreas PSN1 cells (IC₅₀ = 8.9 μg/mL) and inactive against colon HT-29, breast MD-MB-23, and NSCLC lung tumor cells.

Marine natural products

This review covers the literature published in 2013 for marine natural products (MNPs), with 982 citations (644 for the period January to December 2013) 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 (1163 for 2013), 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.

Incisterols, highly degraded marine sterols, are a new chemotype of PXR agonists

During the chromatographic purification of organic extracts obtained from Plakortis cfr. lita we obtained three highly degraded steroid derivatives, the known incisterol A2 (1) and the new incisterols A5 (2) and A6 (3). The new compounds were characterized basing on NMR and MS evidences along with comparison with model compounds. Incisterol A5 proved to bear a 17S-ethyl-15E,18-diene (incisterol numbering system) side chain, found for the first time in a marine organism. The new incisterols A5 and A6 proved to be potent inducers of transactivation of the pregnane X receptor (PXR) and they also stimulate the expression of CYP7A4 and MDR1 with a potency comparable to that of Rifaximin. These observations prompt to consider incisterols A5 and A6 as new potent agonists of PXR. On the other hand, the 17R-methyl analogue incisterol A2 shows only a poor PXR agonist activity. Molecular docking simulations elucidated the binding mechanism of the active incisterols in the ligand binding domain of PXR.