Sterol sulfates

No sterols with sulfate groups in the sidechain have been isolated from sponges to date. This contrasts with echinoderms. Many of the sterol sulfates isolated from echinoderms, especially from ophiuroids (brittle stars) contain sulfate groups in the sidechain [2]. 

A Japanese species of Epipolasis contained five sterol sulfates named halistanol sulfates A-E (536-540), which differ from the original halistanol sulfate (532) from Halichondria moorei [449]. Structures were elucidated by spectroscopic and chemical techniques. Halistanol sulfates F-H (541-543) are three additional sterol sulfates from Pseudaxinyssa digitata that inhibit HIV in vitro [450]. 

The sterol sulfate, halistanol disulfate B (544) was isolated from a South African Pachastrella sp. The structure and stereochemistry of compound 544 were established mainly by interpretation of spectral data. Halistanol disulfate B (544) was active in the endothelin converting enzyme (ECE) assay at a micromolar concentration [451]. Three sterol trisulfates (545-547) have been isolated from the sponges Trachyopsis halichondrioides and Cymbastela coralliophila [452]. 

A Topsentia sp. from Okinawa contained five antimicrobial 14-methyl sterol sulfates, topsentiasterol sulfates A-E (551-555) [458]. 

An unusual 6a-sterol sulfate (557) was isolated from Dysidea fragilis, from the Venetian lagoon and displayed cytotoxicity against two different tumour cell lines in vitro [460]. Tamosterone sulfates (558-559) are a C14 epimeric pair of polyhydroxylated sterols isolated from a new species of Oceanapia [461]. The Japanese marine sponge Epipolasis sp. contained the steroid polasterol B sulfate (560) along with the known compound halistanol sulfate (532). The structure of compound 560 was determined on the basis of spectroscopic evidence and a chemical conversion [462]. 

An Acanthodendrilla sp. from Japan contained ten steroidal sulfates, acanthosterol sulfates A-J (561-570). Acanthosterol sulfates I (569) and J (570) showed antifungal activity against Saccharomyces cervisiae and its mutants [463]. Clathsterol (571), was isolated from the Red Sea sponge Clathria sp. The structure was established mainly by interpretation of spectral data and a chemical transformation. Clathsterol (571) was active against HIV-1 reverse transcriptase (RT) at a concentration of 10 iM [464]. Toxadocia zumi contains three sterol sulfates (572-574) that are antimicrobial, cytotoxic, ichthyotoxic and larvicidal [465]. 

The sterol sulfates haplosamates A (575) and B (576) are inhibitors of HIV-1 integrase from two Philippines Haplosclerid sponges and were reported to be the first naturally occurring sulfamates [466] but the structures were revised after re-examination of spectral data [467],... 

A sterol sulfate, 3(3,4 3-dihydroxypregn-5-en-20-one 3-sulfate (577), was isolated from Stylopus australis from New Zealand and was the first known sterol sulfate with a 5-pregnene skeleton [468]. 

Haliclostanone sulfate (591) is an unusual polyhydroxyl ated sterol sulfate from Haliclona sp. from Malaysia [475]. 

Nakatsu, T., Walker, R.P., Thompson, J.E., and Faulkner, D.J., Biologically active sterol sulfates from the marine sponge Toxadocia zumi, Experientia, 39, 759, 1983. 

Su ate esters. Baumgarten showed that the reagent sulfates substances such as hydrazine, diethylamine, phenol, and naphthalene. It has been used in preparation of carbohydrate sulfate esters, sterol sulfate esters, phenol sulfate esters. 2-Hydroxy-3-alkyl-l,4-naphthoquinone antimalarials can be separated from metabolites hydroxylated in the side chain by conversion of the hydroxylated metabolites into water-soluble sulfate esters and extraction with water. Hydroxy-hydrolapachol (1), which was identified as a metabolite of hydrolapachol and which... 

The chemistry of echinoderms, particularly the Holothuroidea (sea cucumbers) is characterized by the presence of saponins (triterpene glycosides) and sterol sulfates. Saponins are released by the sea cucumber s Cuvier gland when the organism is threatened. A number of biosynthetic investigations have addressed the origins of saponins and have yielded conflicting results. 

These sterol sulfate esters show activity in a number of enzyme and receptor-binding assays and are also active in the anti-HIV screen run at the US National Cancer Institute. A dereplication scheme for this class of compounds has been published by Cardellina et al. (36), in which extracts are chromatographed in three systems Sephadex G-25 for molecular weight C4 wide pore (300) and CIS narrow pore (60 A). Fractions are assayed against HIV and the patterns of activity compared to that observed for halistanol sulfate. Sterol sulfates from six sponge extracts were eluted with methanol H20 (2 1 v/v) and allowed for the rapid dereplication of this class of compound. In... 

Synthesis of polyoxyethylene sterol was first reported by Scotney and Truter [6] in 1971. They simply mixed cholesterol and the appropriate amount of ethylene oxide in a sealed vial during 4 months. Later workers have applied more sophisticated methods to synthesize better defined products. Khachadurian et al. [7] synthesized both polyoxyethylene and methoxypolyoxyethylene derivatives of cholesterol. The former reaction was carried out in dichloromethane using boron trifluoride as catalyst. Derivatives with a methoxy terminal were prepared by condensing methoxypoly(oxyethylene)methanesulfonate with cholesterol in xylene. Commercially available products are produced by the reaction of sterol with ethylene oxide, resulting in a product with a distribution in the number of ethylene oxide (EO) units in the hydrophilic group. Meissner et al. also described the synthesis of sterol sulfate and sulfonate with oxy-ethylene spacers [8], The synthesis of sterol surfactants has been covered in a review by Folmer [9]. There are only a few producers of polyoxyethylene... 

Treatment of sterols with chlorosulfonic acid provides a valuable synthetic route to high yields of pure sterol sulfates (Chapter 5, Section 3). 

D Auria et al. (654) found two groups of sterol sulfates in the aqueous extract of the starfish Euretaster insignis. Hydrolysis of the less polar fraction gave cholest-7-en-3 P-ol and C26 C27, C28, and C29 5a-steroidal alcohols. The more polar fraction contained sulfated 3p,21-dihydroxysteroids. After solvolysis to remove the sulfate groups the steroids were identified as (20i )-24-methylenecholestane-3P,21-diol (981), (20R)-24-methylenecholest-5-ene-3p,21-diol (982), (20/ ,22 )-24-methylcholest-22-ene-3P,21-diol (983), (20/ )-choles-tane-3p,21-diol (984), (207 ,22 )-cholest-22-ene-3p,21-diol (985), and (207 )-cholest-5-ene-3P,21-diol (986). This starfish was apparently devoid of saponins. 

Two Other 3a-hydroxy sterols, sulfated at position 26, were isolated from a single specimen of a sea star collected in Antarctica. These sterols result from the oxidation of a hydroxyl at position 6, common among asterids. This starfish has not been identified to the genus level, but belongs to the family Asteriidae (De Marino et al., 1997a). 

Fu, X., Schmitz, F.J., Lee, R.H., Papkoff, J.S., and Slate, D.L. (1994) Inhibitors of protein tyrosine kinase pp60 sterols sulfates from the brittle star Ophioarachna incrassata. J. Nat. Prod., 57, 1591-1594. 

A-nor-Sterols sulfated sterols chlorinated sesquiterpenes pyrrole-imidazole alkaloids long-chain isothiocyanates cyclic depsipeptides... 

Fujita, M., Nakao, Y, Matsunaga, S., Seiki, M., Itoh, Y, Van Soest, R,W, M., Heubes, M., Faulkner, D.J., and Fusetani, N, (2001b) Isolation and structure elucidation of two phosphorylated sterol sulfates, MTl-MMP inhibitors from a marine sponge Cribochalina sp, revision of the structures of haplosamates A and B. Tetrahedron, 57, 3885-3890,... 

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