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 () and the flexible diterpenoid, sangiangol B (), isolated from a marine soft coral, sp., was supported by quantum chemical calculations of NMR chemical shifts at DFT levels. The relative configuration of antheliol is now revealed, as 1, 4, 7, 10 as in , whereas sangiangol B () has complete stereochemistry as 1, 7, 8, 10, 11, 12.

Oxy-Polybrominated Diphenyl Ethers from the Indonesian Marine Sponge, : X-ray, SAR, and Computational Studies.

Polybrominated diphenyl ether (PBDE) compounds, derived from marine organisms, originate from symbiosis between marine sponges and cyanobacteria or bacteria. PBDEs have broad biological spectra; therefore, we analyzed structure and activity relationships of PBDEs to determine their potential as anticancer or antibacterial lead structures, through reactions and computational studies. Six known PBDEs (-) were isolated from the sponge, ; C NMR data for compound are reported for the first time and their assignments are confirmed by their theoretical C NMR chemical shifts (RMSE < 4.

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

A new, rare trinor-dolabellane diterpenoid, sangiangol A (), and one new dolabellane diterpenoid, sangiangol B (), together with known cembranes and dolabellanes (-), were isolated from the ethyl acetate layer of an extract of an Indonesian marine soft coral, sp. Compounds - exhibited moderate cytotoxicity against an NBT-T2 cell line (0.5-10 µg/mL).

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.

A New Trinor-guaiane Sesquiterpene from an Indonesian Soft Coral Anthelia sp.

A new trinor-guaiane sesquiterpene has been isolated from an Indonesian soft coral Anthelia sp. The planar structure, possessing an octahydroazulene skeleton, and relative stereochemistry were established by analyzing 1D and 2D NMR data, including NOE experiments. Its absolute stereochemistry was elucidated to be 1S, 4S, 7R, and 10R by comparing observed and calculated optical rotation values.

Polybrominated diphenyl ethers from the Indonesian sponge Lamellodysidea herbacea.

Four new (1-4) and 10 known polybrominated diphenyl ethers (5-14) have been isolated from the title sponge. The structures of the new entities were elucidated by interpretation of spectroscopic data and chemical transformations. These metabolites showed potent antimicrobial activity against Bacillus subtilis and moderate/weak cytotoxicity against NBT-T2 rat bladder epithelial cells.