Halistanol sulfates

Halistanol sulfate (532) from Halichondria cf. moorei is a tris-sodium sulfate salt, which possesses antimicrobial, hemolytic, and ichthyotoxic activity [444]. It was later isolated from two sponges of the genus Topsentia as the free sterol and found to inhibit pp60v-src protein tyrosine kinase activity [445]. The tris(2-aminoimidazolium) salt of halistanol sulfate (533) was isolated from Topsentia sp. from Japan and is also antimicrobial [446]. 

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]. 

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]. 

Additionally, sulfated sterols have been described from a wide variety of marine organisms, particularly sponges and echinoderms, and several of these steroidal sulfates have exhibited a broad range of activities. Halistanol sulfates are a group of sulfated polyhydroxysteroids from... 

Fusetani, N., Matsunaga, S., and Konosu, S., Halistanol sulfate an antimicrobial steroid sulfate from Halichondria cf. moorei Bergquist, Tetrahedron Lett., 22, 1985, 1981. 

Many marine organisms contain compounds that possess a sulfate ester functionality. These compounds tend to be active in a number of receptor binding and enzyme bioassays and can often be difficult to purify. They tend to occur as a series of closely related compounds that are both very polar and labile to acid or base treatment. Perhaps the most commonly occurring sulfate ester is halistanol sulfate (Scheme 5), first reported from Halichondna cf moorei (34). 

Halistanol sulfate was purified by successive chromatography of the water-soluble portion of an aqueous ethanol extract using a TSK G3000S gel, silica gel, and a Sephadex LH-20 stationary phase. Antimicrobial fractions from the LH-20 separation were further purified by recrystallization from Et0H-H20. 

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... 

A few halidiondrid sponges, such as Pseudaxinyssa sp., contain sterols substituted at 24 with an isopropyl group (Figure 19.20), and this relatively rare feature of the side chains occurs in an Epipolasis sp. harvested in Japan and in Ciocalypta sp. collected in Senegal (Do et al, 2009). This species contains polasterol A, polasterol B sulfate and 24-isopropylcholesterol, as well as halistanol sulfate, which was isolated in 1981 from Halichondria sp., also of... 

Bifulco, G., Bruno, I., Minale, L., and Riccio, R. (1994a) Novel HIV-inhibitory halistanol sulfates F-H from a marine sponge, Pseudoaxinyssa digitata. J. Nat. Prod., 57,164—167. 

Kanazawa, S., Fusetani, N., and Matsunaga, S. (1992) Halistanol sulfates A-E, new steroid sulfates from a marine sponge, Epipolasis sp. Tetrahedron, 48, 5467-5472. 

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