Cytotoxic 5‐Hydroxyindole Alkaloids from the Marine Sponge Scalarispongia sp.

Three new 5‐hydroxyindole alkaloids ( 1 , 2 , 3 ) along with seven known analogs ( 4 , 5 , 6 , 7 , 8 , 9 , 10 ) were isolated from a Dokdo marine sponge Scalarispongia sp. The elucidation of the structures of the new compounds by spectroscopic analyses indicated that these compounds were an indole glyoxylate ( 1 ), a mono‐indole analog of hyrtinadine A ( 2 ), and a symmetrical bis‐indole with pyridine linker ( 3 ). The comparison of IC₅₀ values for obtained compounds against a human leukemia cell line revealed that the bis‐indole structure is a requirement for cytotoxicity.     

Differential inhibition of postnatal brain,spinal cord and body growth by a growth hormone antagonist

Background  

Growth hormone (GH) plays an incompletely understood role in the development of the central nervous system (CNS). In this study, we use transgenic mice expressing a growth hormone antagonist (GHA) to explore the role of GH in regulating postnatal brain, spinal cord and body growth into adulthood. The GHA transgene encodes a protein that inhibits the binding of GH to its receptor, specifically antagonizing the trophic effects of endogenous GH.     

Topsentiasterol sulfates with novel iodinated and chlorinated side chains from the marine sponge Topsentia sp.

Three new marine polar steroids, the first chlorine-containing steroid sulfate (1), topsentiasterol sulfate F (2) and the first natural iodinated steroid (3) have been isolated from the marine sponge Topsentia sp. The structures of 1-3 were elucidated using NMR and HRESIMS as well as by chemical correlation of 1 with previously known topsentiasterol sulfate D. Compound 1 proved to be an effective inhibitor of endo-1,3-β-d-glucanase from the marine mollusc Spisula sachalinensis.     

Metabolites of the marine sponge <Emphasis Type="Italic">Suberites cf. aurantiacus</Emphasis>

Fractions of free sterols and sterol esters were observed in the ethylacetate extract of the marine sponge Suberites cf. aurantiacus and their compositions were determined. It was found that cholesterol was the predominant component in all sterol forms. The esters had a high content of unsaturated long-chain fatty acids (C₂₄–C₂₆). Sterol acetates have not been previously observed in marine invertebrates.     

New meroterpenoids from the marine sponge Aka coralliphaga

Three new sulfated meroterpenoids containing sesquiterpene and hydroquinone moieties, namely siphonodictyal A sulfate (1), akadisulfate A (2) and akadisulfate B (3), along with the known siphonodictyal B3 and bis(sulfato)-cyclosiphonodictyol A were isolated from the sponge Aka coralliphaga. Their structures were elucidated on the basis of spectroscopic data. Akadisulfate B and siphonodictyal B3 showed a radical-scavenging activity comparable with that of the known lipophylic antioxidant BHT.