Stoloniferone-a, -b, -c, and -d, four new cytotoxic steroids from the okinawan soft coral clavularia viridis

Chemical Review of Gorgostane-Type Steroids Isolated from Marine Organisms and Their 13C-NMR Spectroscopic Data Characteristics

Gorgostane steroids are isolated from marine organisms and consist of 30 carbon atoms with a characteristic cyclopropane moiety. From the pioneering results to the end of 2021, isolation, biosynthesis, and structural elucidation using ¹³C-NMR will be used. Overall, 75 compounds are categorized into five major groups: gorgost-5-ene, 5,6-epoxygorgostane, 5,6-dihydroxygorgostane, 9,11-secogorgostane, and 23-demethylgorgostane, in addition to miscellaneous gorgostane. The structural diversity, selectivity for marine organisms, and biological effects of gorgostane steroids have generated considerable interest in the field of drug discovery research.

Chemical Diversity of Soft Coral Steroids and Their Pharmacological Activities

The review is devoted to the chemical diversity of steroids produced by soft corals and their determined and potential activities. There are about 200 steroids that belong to different types of steroids such as secosteroids, spirosteroids, epoxy- and peroxy-steroids, steroid glycosides, halogenated steroids, polyoxygenated steroids and steroids containing sulfur or nitrogen heteroatoms. Of greatest interest is the pharmacological activity of these steroids. More than 40 steroids exhibit antitumor and related activity with a confidence level of over 90 percent. A group of 32 steroids shows anti-hypercholesterolemic activity with over 90 percent confidence. Ten steroids exhibit anti-inflammatory activity and 20 steroids can be classified as respiratory analeptic drugs. Several steroids exhibit rather rare and very specific activities. Steroids exhibit anti-osteoporotic properties and can be used to treat osteoporosis, as well as have strong anti-eczemic and anti-psoriatic properties and antispasmodic properties. Thus, this review is probably the first and exclusive to present the known as well as the potential pharmacological activities of 200 marine steroids.

Computational Tools in the Discovery of FABP4 Ligands: A Statistical and Molecular Modeling Approach

Small molecule inhibitors of adipocyte fatty-acid binding protein 4 (FABP4) have received interest following the recent publication of their pharmacologically beneficial effects. Recently, it was revealed that FABP4 is an attractive molecular target for the treatment of type 2 diabetes, other metabolic diseases, and some type of cancers. In past years, hundreds of effective FABP4 inhibitors have been synthesized and discovered, but, unfortunately, none have reached the clinical research phase. The field of computer-aided drug design seems to be promising and useful for the identification of FABP4 inhibitors; hence, different structure- and ligand-based computational approaches have been used for their identification. In this paper, we searched for new potentially active FABP4 ligands in the Marine Natural Products (MNP) database. We retrieved 14,492 compounds from this database and filtered through them with a statistical and computational filter. Seven compounds were suggested by our methodology to possess a potential inhibitory activity upon FABP4 in the range of 97–331 nM. ADMET property prediction was performed to validate the hypothesis of the interaction with the intended target and to assess the drug-likeness of these derivatives. From these analyses, three molecules that are excellent candidates for becoming new drugs were found.

Endangered medicinal species of the Indian Ocean: radical need for conservation

Life originated in the Oceans, which are also the most fertile source of chemically distinctive natural products that are mainly accumulated in living organisms. Several of these compounds show pharmacological activities, and are helpful for the invention and discovery of bioactive compounds, primarily for several fatal diseases. The Indian Ocean is home to several exotic species of flora and fauna. Several environmental and man-made factors are responsible for deterioration of several precious biodiversity areas of the Ocean. The author, while highlighting the medicinal importance of these organisms, underlines the need for comprehensive conservatory measures on the part of the international community to be taken in order to maintain the rich Oceanic biodiversity.

New anti-inflammatory steroids from the Formosan soft coral Clavularia viridis

Four new steroids, stoloniferones R-T (1-3), and (25S)-24-methylenecholestane-3 beta,5 alpha,6 beta-triol-26-acetate (4) were isolated from the methylene chloride solubles of the soft coral Clavularia viridis. The structures of the metabolites were elucidated by extensive spectral analysis and their anti-inflammatory activity was measured in vitro.

New cytotoxic steroids from the soft coral Clavularia viridis

Ten new cytotoxic steroids, stoloniferones H-Q (1-10) were isolated from the methylene chloride solubles of the soft coral Clavularia viridis. The structures of the metabolites were elucidated on the basis of spectroscopic (IR, MS, and 1D and 2D NMR) analysis and their cytotoxicity against selected cancer cells was measured in vitro.

Three new chlorinated marine steroids, yonarasterols G, H and I, isolated from the okinawan soft coral, Clavularia viridis

Three new chlorinated marine steroids, yonarasterols G, H and I, were isolated from the Okinawan soft coral, Clavularia viridis. Their structures including the absolute configuration were determined based on the results of spectroscopic analysis and chemical conversion.

New marine steroids, yonarasterols, isolated from the okinawan soft coral, Clavularia viridis

Six new marine steroids, yonarasterols A through F, were isolated from the Okinawan soft coral, Clavularia viridis. Their structures were determined based on the results of spectroscopic analysis.

New bioactive marine steroids from the Okinawan soft coral Clavularia viridis

Eight new marine steroids were isolated from the Okinawan soft coral Clavularia viridis Quoy and Gaimard. Their structures were determined based on spectroscopic analysis, chemical conversion, and X-ray crystallographic analysis. Steroids 5 and 6 showed growth inhibition activity toward HeLa S3 cells and human diploid cells in vitro.

The effect of 9,11-secosterol, a newly discovered compound from the soft coral Gersemia fruticosa, on the growth and cell cycle progression of various tumor cells in culture

A new 9,11-secosterol, 24-nor-9,11-seco-11-acetoxy-3 beta,6 alpha-dihydroxycholest-7,22(E)-dien-9-one, was found to exhibit growth inhibitory (IC50 below 10 microM) and cytotoxic activities against human leukemia K562, human cervical cancer HeLa, and Ehrlich ascites tumor cells in vitro. The cytostatic concentrations of the compound generally caused the G2/M block in the cell cycle progression, but differences between the three tumor cell lines in the events leading to cell death were remarkable. While inhibiting cell proliferation, 9,11-secosterol caused accumulation of HeLa and K562 cells in the metaphase of mitosis. So, abnormal mitosis can play an important role in the cytotoxicity of 9,11-secosterol in these cell lines. In the Ehrlich ascites tumor cell line the increasing concentrations of the drug (up to 40 microM) did not cause an immediate cell killing. Instead, due to continued DNA synthesis without entry into mitosis, cells with high DNA ploidy were produced. It was shown that the cytoskeletal systems such as microtubules and microfilaments were not damaged by the action of 9,11-secosterol. Further studies are necessary to elucidate the mechanism of the cytotoxic effect of 9,11-secosterol.

Widespread but variable toxicity in scleractinian corals

Aqueous and/or aqueous ethanol extracts were made of 58 scleractinian species from 11 families, collected from Heron Island, Great Barrier Reef. At least one extract from each of 53 species (91%) exhibited activity against at least one bioassay system. Extracts from at least one colony of each of 41 species of the 58 tested were toxic to mice when injected i.p. Cytolysis of sheep red blood cells was produced by extracts from at least one colony of each of 49 species of the 57 species tested and antibacterial activity was present in extracts from at least one colony of each of 37 species of the 55 tested. Only four species from 45 species assayed yielded extracts toxic to mosquito fish. This is the first report of bioactivity in extracts of 46 species of coral and the first report of bioactivity of extracts of corals from the families Mussidae, Merulinidae, Siderastreidae, Oculinidae and Dendrophylliidae. Variable results on a particular bioassay exhibited by extracts from different colonies of a given species were analysed by the Generalized Linear Interactive Modelling system (GLIM). Toxicity to mice, cytolytic and antimicrobial activity are not significantly correlated with each other. No model could be generated to explain the variation in the incidence of cytolytic activity nor of antimicrobial activity. However antimicrobial activity varied significantly between collection trips and was negatively associated with the presence of immature gonads in the colonies. The model predicts that toxicity to mice will be higher in extracts collected when average maximum monthly air temperature is high.