Search

Context: Epidioxy sterols and sterols with special side chains, such as hydroperoxyl sterols, usually obtained from marine natural products, are attractive for bioactivities. Objective: To isolate and screen bioactive and special sterols from China Sea invertebrates. Materials and methods: Two hydroperoxyl sterols ( 1 and 2) from the sponge Xestospongia testudinaria Lamarck (Petrosiidae), three epidioxy sterols ( 3- 5) from the sea urchin Glyptocidaris crenularis A. Agassiz (Glyptocidaridae), sponge Mycale sp. (Mycalidae) and gorgonian Dichotella gemmacea Milne Edwards and Haime (Ellisellidae) and an unusual sterol with 25-acetoxy-19-oate ( 6) also from D. gemmacea were obtained and identified. Using high-throughput screening, their bioactivities were tested toward Forkhead box O 3a (Foxo3a), 3-hydroxy-3-methylglutaryl CoA reductase gene fluorescent protein (HMGCR-GFP), nuclear factor kappa B (NF-κB) luciferase, peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α), protein-tyrosine phosphatase 1B (PTP1B), mitochondrial membrane permeabilization (MMP) and adenosine monophosphate-activated protein kinase. Results: Their structures were determined by comparing their nuclear magnetic resonance data with those reported in the literature. Three epidioxy sterols ( 3- 5) showed inhibitory activities toward Foxo3a, HMGCR-GFP and NF-κB-luciferase with the IC50 values 4.9-6.8 μg/mL. The hydroperoxyl sterol 29-hydroperoxystigmasta-5,24(28)-dien-3-ol ( 2) had diverse inhibitory activities against Foxo3a, HMGCR-GFP, NF-κB-luciferase, PGC-1α, PTP1B and MMP, with IC50 values of 3.8-19.1 μg/mL. Discussion and conclusion: The bioactivities of 3- 5 showed that 5α,8α-epidioxy is the active group. Otherwise, the most plausible biosynthesis pathway for 1 and 2 in sponge involves the abstraction of an allylic proton by an activated oxygen, such as O2, along with migration of carbon-carbon double bond. Therefore, the bioactive and unstable steroid should be biosynthesized in sponge under a special ecological environment to act as a defensive strategy against invaders. [ABSTRACT FROM AUTHOR]

Our study of the secondary metabolites of coral-associated fungi produced a valuable and extra-large chemical database. Many of them exhibit strong biological activity and can be used for promising drug lead compounds. Serving as an epitome of the most promising compounds, which take the ultra-new skeletons and/or remarkable bioactivities, this review presents an overview of new compounds and bioactive compounds isolated from coral-associated fungi, covering the literature from 2010 to 2021. Its scope included 423 metabolites, focusing on the bioactivity and structure diversity of these compounds. According to structure, these compounds can be roughly classified as terpenes, alkaloids, peptides, aromatics, lactones, steroids, and other compounds. Some of them described in this review possess a wide range of bioactivities, such as anticancer, antimicrobial, antifouling, and other activities. This review aims to provide some significant chemical and/or biological enlightenment for the study of marine natural products and marine drug development in the future. [ABSTRACT FROM AUTHOR]

The article discusses the study about the isolation, characterization and bioactivity evaluation from the six known alkaloids of marine soft coral Sinularia kotanianensis collected from the South China sea. Topics discussed include the extraction of the collected soft coral Sinularia k. for three times with ethyl alcohol (EtOH), the extraction of the petroleum ether was subjected to silica gel column chromatography and the used of tyramine as a catecholamine drug.

The article presents a study which discusses the bioactive components of wet marine sponges Axinella, which belongs to the family of Axinellidae. It states that Axinella was found to consist six chemical compounds which were determined using nuclear magnetic resonance (NMR) spectroscopy. It adds that the ecological origin and secondary metabolites of Axinella are anticipated to be useful for further chemotaxonomic research about marine sponges.

The article discusses a study which investigates the bioactive chemical components of the starfish Stellaster equestris, with seven compounds which were isolated from the S. equestris' ethyl acetate extracts. The study used petroleum ether, ethyl acetate, and n-butanol to partition the ethanol extract. Results show that the isolated compounds has showed moderate activity against Escherichia coli.

The article presents chemical formulas for the article "Guignardins A-F, Spirodioxynaphthalenes from the Endophytic Fungus Guignardia sp. KcF8 as a New Class of PTP1B and SIRT1 Inhibitors" by D. Killander and others, published in the "European Journal of Organic Chemistry" in 2014.