V. A. Stonik

Antitumor activity of the immunomodulatory lead Cumaside

A new immunomodulatory lead Cumaside that is a complex of monosulfated triterpene glycosides from the sea cucumber Cucumaria japonica and cholesterol possesses significantly less cytotoxic activity against sea urchin embryos and Ehrlich carcinoma cells than the corresponding glycosides. Nevertheless Cumaside has an antitumor activity against different forms of experimental mouse Ehrlich carcinoma in vivo both independently and in combination with cytostatics. The highest effect occurs at a treatment once a day for 7 days before the tumor inoculation followed by Cumaside treatment once a day for 7 days. Prophylactic treatment with Cumaside and subsequent therapeutic application of 5-fluorouracil suppressed the tumor growth by 43%.

Free sterol compositions from the sea cucumbers Pseudostichopus trachus, Holothuria (Microtele) nobilis, Holothuria scabra, Trochostoma orientale and Bathyplotes natans

Abstract Free sterol fractions from the sea cucumbers Pseudostichopus trachus , Holothuria ( Microtele ) nobilis , Holothuria scabra, Bathyplotes natans and Trochostoma orientale have been isolated and studied by HPLC, GLC, GLC–MS, and NMR methods. About 80 sterols were found and 69 of these were identified, including several new and rare ones. Peculiarities of biosynthesis and metabolism of sterols, as well as a probable evolutionary influence of the presence of membranolytic oligoglycosides on compositions of free sterol fractions in these sea cucumbers, are discussed.

Ulososide B, a new unusual norlanostane-triterpene glycoside and its genuine aglycone from the Madagascar sponge Ulosa sp.

A new triterpene glycoside, ulososide B (1), was isolated from the sponge Ulosa sp and its structure was elucidated on the basis of spectroscopic data and obtaining of genuine aglycone (2) after acid hydrolysis.

Sulfated steroid compounds from the starfish Aphelasterias japonica of the Kuril population

Four sulfated steroid compounds were isolated from the Kuril population of the starfish Aphelasterias japonica. The structure of a new glycoside, aphelasteroside D, was elucidated as (24R)-29-O-[2-O-sulfo-β-D-glucopyranosyl]-24-ethyl-5α-cholestane-3β,5,6β,8β,15α,29-hexol sodium salt. Other three substances were identified as the known pycnopodioside C, 3-O-sulfo-24,25-dihydromarthasterone, and 3-O-sulfothornasterol A, the latter compound being isolated as a tyrammonium salt for the first time.

Secondary metabolites of the Vietnamese nudibranch mollusk Phyllidiella pustulosa

The chemical composition of the EtOH extract of the nudibranch mollusk Phyllidiella pustulosa was studied. Six sesquiterpenoids including the novel secondary metabolite (+)-10(R)-isothiocyanoalloaromodendrane were isolated. The steroid composition of the extract was studied. The structures of three previously known ketosteroids and six sterols were identified.

Synthesis of substituted tryptanthrins via oxidation of isatin and its derivatives

Oxidation of isatin and its 5-substituted analogs with potassium permanganate in anhydrous acetonitrile gave indolo[2,1-b]quinazoline-6,12-dione (tryptanthrin) and its 2,8-dimethyl-, 2,8-dibromo-, and 2,8-diiodo derivatives. Oxidative coupling of 5,7-dichloroisatin with isatin under analogous conditions afforded 2,4-dichloroindolo[2,1-b]quinazoline-6,12-dione, while 1,4-dichloroindolo[2,1-b]quinazoline-6,12-dione and 1,4-dichloro-8-methylindolo[2,1-b]quinazoline-6,12-dione were obtained by oxidative coupling of 4,7-dichloroisatin with isatin and 5-methylisatin, respectively.

Marine bioorganic chemistry as the base of marine biotechnology

Studies carried out at the Pacific Institute of Bioorganic Chemistry of the Far-Eastern Branch of the Russian Academy of Sciences and at other centers of structural investigation of marine organism metabolites were used as examples to consider some features of the biochemistry of marine natural products and the achievements of marine bioorganic chemistry, which open up ways to the development of new drugs and biological preparations.

Asterosaponin P2 from the Far-Eastern starfishpatiria (asterina) pectinifera

A new polyhydroxylated steroidal glycoside, asterosaponin P2, was isolated from the Far-Eastern starfishPatiria (Asterina) pectinifera. The glycoside was identified as the 24R)-29-O-[2-O-sulfo-α-L-arabinofuranosyl]-24-ethyl-5α-cholestane-3β, 6α,8β,15α,16β,29-hexol Na salt.

Steroid compounds from far Eastern starfishes Henricia aspera and H. tumida

Six new natural compounds were isolated from two Far Eastern starfish species, Henricia aspera and H. tumida, collected in the Sea of Okhotsk. Two new glycosylated steroid polyols were obtained from H. aspera: asperoside A and asperoside B, which were shown to be (20R,24R, 25S)-3-O-(2,3-di-O-methyl-β -D-xylopyranosyl)-24-methyl-5α-cholest-4-ene-3β, 6β,8,15α,16β,26-hexaol and (20R, 24R,25S,22E)-3-O-(2,4-di-O-methyl-β-D-xylopyranosyl)-24-methyl-5α-cholest-22-ene-3β,4β,6β,8,15α,26-hexaol, respectively. Two other glycosylated polyols, tumidoside A, with the structure elucidated as (20R, 22E)-3-O-(2,4-di-O-methyl-β -D-xylopyranosyl)-26,27-dinor-24-methyl-5α-cholest-22-ene-3β,4β,6β,8,15α,25-hexaol, and tumidoside B, whose structure was elucidated as (20R,24S)-3-O-(2,3-di-O-methyl-β-D-xylopyranosyl)-5α-cholestan-3β,4β,6β,8,15α,24-hexaol, were isolated from the two starfish species. (20R, 24S)-5α-Cholestan-3β,6β,15α,24-tetraol and (20R, 24S)-5α-cholestan-3β,6β,8,15α,24-pentaol were identified only in H. tumida. The known monoglycosides henricioside H1 and laeviuscolosides H and G were also identified in both species.

Steroid compounds from the Far Eastern starfish Diplopteraster multipes

Sodium salt of (20R)-3α,4β-dihydroxycholest-5-ene-21-yl sulfate and disodium salts of (20R)-4β-hydroxycholest-5-ene-3α,21-diyl disulfate, (20R)-24-methylcholest-5,24(28)-diene-3α,21-diyl disulfate, (20R)-24-methyl-5α-cholest-24(28)-ene-3α,21-diyl disulfate, (20R)-cholest-5-ene-3α,21-diyl disulfate, (20R)-5α-cholestane-3α,21-diyl disulfate, and (20R)-3α-hydroxycholest-5-ene-2β,21-diyl disulfate were isolated from the far eastern starfish Diplopteraster multipes and characterized. These compounds differ structurally from sulfated polyhydroxysteroids in other starfish species. At the same time, they are typical secondary metabolites of Ophiuroidea and have some structural features characteristic of the ophiuroid-isolated steroids, namely the 3α-hydroxy (or 3α-sulfoxy) and 21-sulfoxy groups. These data support the opinion of some taxonomists that starfishes and ophiuroids are phylogeneteically related classes and are closer to each other than to other classes of the Echinodermata phylum.