Sangiangols A and B, Two New Dolabellanes from an Indonesian Marine Soft Coral, Anthelia sp

Lamellodysideol, a new flexible marine norditerpenoid from the Indonesian marine sponge Lamellodysidea herbacea

One new acyclic norditerpenoid, lamellodysideol (1) was isolated from the Indonesian marine sponge Lamellodysidea herbacea together with known phytol (2). The structure of 1 was determined on the basis of spectral evidence and by comparison with known related molecules including optical rotation data. The relative configurations of 1d and 2b were proposed using quantum chemical calculation of NMR chemical shifts at DFT levels. In addition, the relative configuration of 2b was also supported by Newman's rule of six and confirmed through Hehre's protocol. Compounds 1d and 2b showed toxicity against NBT-T2 cells assay at 10 µg/mL.

Can the global marine aquarium trade (MAT) be a model for sustainable coral reef fisheries?

Globally, 6 million coral reef fishers provide ~25% of emergent countries' catch, but species have low value. The marine aquarium trade (MAT) targets high-value biodiversity, but missing data amplify draconian governance and demand for international prohibition. To stimulate sustainability and reef conservation investment, we generate a fiscal baseline using the first global analysis of numbers, diversity, and biomass of MAT-traded organisms. Each year, ~55 million organisms worth US$2.15 billion at retail are traded comparable with major fisheries, e.g., tuna. A sustainable MAT also requires overexploitation assessments. We identify 25 species/genera with "Extremely High" risk ratios and place the Indonesian and Sulu-Celebes Seas in the highest exploitation category. Despite predicted hobbyist number increases, unabated reef degradation and low governance will transform the MAT into an aquaculture-dominated industry decoupled from communities (i.e., culture located in importing countries). A "MAT-positive" future requires evidence-based management/governance, consumer education, and sustainable practice incentivization but can address the biodiversity and social and economic inequality crises.

Stereochemical determination of NMR chemical shifts in marine terpenoids, antheliol and sangiangol B, using DFT calculations

Stereochemical determination of the flexible trinor-guaiane sesquiterpenoid, antheliol (1a) and the flexible diterpenoid, sangiangol B (2a), isolated from a marine soft coral, Anthelia sp., was supported by quantum chemical calculations of NMR chemical shifts at DFT levels. The relative configuration of antheliol is now revealed, as 1S*, 4S*, 7S*, 10R* as in 1b, whereas sangiangol B (2c) has complete stereochemistry as 1S*, 7R*, 8R*, 10R*, 11R*, 12S*.

Targeted Isolation of Dolabellane Diterpenoids from the Soft Coral Clavularia viridis Using Molecular Networking

LC-MS/MS-based molecular networking annotation coupled ¹H NMR detection allowed the depiction of the soft coral Clavularia viridis to produce a profile of dolabellane-type diterpenoids. Chromatographic separation of the EtOAc fraction resulted in the isolation of 12 undescribed dolabellane-type diterpenoids, namely, clavirolides J-U (1-12). Their structures were characterized by the extensive analysis of the spectroscopic data, including the calculated ECD and X-ray diffraction for the configurational assignments. Clavirolides J-K are characterized by a 1,11- and 5,9-fused tricyclic tetradecane scaffold fused with a α,β-unsaturated-δ-lactone, and clavirolide L possesses a 1,11- and 3,5-fused tricyclic tetradecane scaffold, which extend the dolabellane-type scaffolds. Clavirolides L and G showed significant inhibition against HIV-1 without RT enzyme inhibition, providing additional non-nucleosides with different mechanisms from efavirenz.

Marine natural products

Covering: 2020This review covers the literature published in 2020 for marine natural products (MNPs), with 757 citations (747 for the period January to December 2020) 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 (1407 in 420 papers for 2020), 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. A meta analysis of bioactivity data relating to new MNPs reported over the last five years is also presented.

Dolabellane Diterpenoids from the Xisha Soft Coral Clavularia viridis

Twelve new members (1-12) of the dolabellane family, co-occurring with three related known diterpenoids (13-15), were isolated from the Xisha soft coral Clavularia viridis. Their structures were determined by extensive spectroscopic analysis, modified Mosher's method, and X-ray diffraction analysis. Clavuperoxylides A (3) and B (4) represent the first examples of dolabellanes containing peroxyl groups, especially the novel peroxide bridge in 4, whereas clavufuranolides A-C (9-11) are the first example of dolabellane diterpenoids comprising a tetrahydrofuran ring. The possible biogenetic relationship of all the isolates was proposed. In bioassay, several compounds exhibited considerable cytotoxicity against A549 and P388 cell lines. Compound 7 exhibited inhibitory activity against protein tyrosine phosphatases 1B (PTP1B), an anti-diabetic target, representing the first report of PTP1B inhibitory activity for dolabellane diterpenoids.

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.