Polyhydroxy sterols

A number of polyhydroxy sterols were isolated from coelenterata 25-hydroxy-... 

Several polyhydroxy sterols were isolated from octocorals, alcyonaceans, gorgonians and other marine sources. Hippurin-I (58) [66], 3a-acetoxy-ll -hydroxy-24-methyl-22,25-epoxy-5a-furostan-18,20/S-lactone (59), 3a-acetoxy-24-methyl-ll/8,18 18,20/J 22,25-triepoxy-5a-furostane (60) and several of their analogues were isolated from Isis hippuris collected in Okinawa by Higa [67]. A polyhydroxy sterol (61) containing the gorgosterol side chain was also present [68] (Fig. 6). 

The polyoxygenated sterols correspond to the polyhydroxy sterols in the tetracydic system and all corresponding oxidation derivatives - ketones and polyketones for the most part - and also epoxides. Almost all of these sterols... 

The species Myxoderma platyacanthum and Tremaster novaecaledoniae contain unusual polyhydroxy-sterols for which there are no known equivalents in other species. In the first species (M. platyacanthum), the side chain is an amide whose carbonyl derives from the oxidation of carbon 26 and the nitrogenous part of taurine. The second species (T. novaecaledoniae) contains the first knovm example of a phosphoric ester in position 6a with a classical side chain. This phosphoric ester is in addition associated with asterosaponins, also phosphorylated (see below). The role of these exceptional derivatives in these two sea stars seems not yet be known. Minutoside B is a glycoside isolated from the starfish Anasterias minuta harvested in Patagonia whose aglycone has the same atypical side chain of steroids as that found in Myxoderma platyacanthum (Chludil and Maier, 2005). 

The bile salts of Chondridithyes (rays and sharks) are stdfated derivatives of polyhydroxy sterols, whose two main representatives are scymnol and chimaerol. 

Isaacs, S., Berman, R., Kashman, Y, Gebreyesus, T., and Yosief, T. (1991) New polyhydroxy sterols, dysidamides, and a dideoxyhexose from the sponge Dysidea herbacea. J. Nat. Prod., 54, 83—91. 

Sauleau, P. and Bourguet-Kondradd, M.-L. (2005) Novel polyhydroxy-sterols from the Red Sea marine sponge Lamdlodysidea herbacea. Steroids, 70, 954-959. 

Tsukamoto, S., Tatsuno, M., Van Soest, R.W.M., Yokosawa, H and Ohta, T. (2003) New polyhydroxy sterols proteasome inhibitors from a marine sponge Acanthodendrilla sp. J. Nat, Prod, 66,1181-1185. 

Kobayashi, M., Kanda, F., Rao. C.V.L., Kumar, S.M.D., Rao, D.V., and Rao, C.B. (1991b) Polyhydroxy-sterols of the soft corals of Andaman and Nicobar coasts. 3. Isolation and stmcture of five new C28 polyhydroxysterols from two Sclerophytum. Chem. Pharm. Bull, 39,... 

Bile alcohols are polyhydroxy C27 sterols that serve as intermediates in the biosjmthesis of cholic acid and chenodeoxycholic acid from cholesterol (1, 2). Recently several studies have shown that increased amounts of bile alcohols namely 27-nor-5p-cholestane-3a,7a,12a,24, 25-pentol and 5P-cholestane-3a, 7a,12a,25,26-pentol are excreted (as glucuronides in urine of patients with liver diseases such as primary biliary cirrhosis (3), liver cirrhosis (4, 5) and a-antitrypsin deficiency (6). Ichimiya et. al., described the occurrence of 5P-cholestane-3a,7a,12a,26,27-pentol (5P-cyprinol) and 5P-cholestane-3a,7a,... 

Kobayashi, M. (1994a) Marine sterols. Part 28. New (17F)-polyhydroxy-23—24-dimethylcholesta-5,17(20)-dienes from the soft coral Sirudaria mayi.J, Chem, Res, (S), 44—45. 

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