Salamandra alkaloids

Samandarin, molecular formula C19H31NO2, is the major steroidal alkaloid of the skin glands of the fire salamander (Salamandra salamandra), and is extremely toxic. The toxicides of samandarin include muscle convulsions, raised blood pressure and hyperventilation. 

The European fire salamander (Salamandra salamandra) and the alpine salamander (Salamandra atra) are the only amphibians known to contain samandarine alkaloids. These are the only two species in this genus. The proposal that extracts of the brilliant black and yellow Australian myobatrachid frog Pseudophryne corroboree contained samandarine alkaloids (52) has proved to be incorrect, and this and other frogs of the genus Pseudophryne instead contain pumiliotoxins and pseudophrynamines (see Sections III,C and VII, A). The major alkaloids of Salamandra salamandra are samandarine, samandarone, and 0-acetylsamandarine. There do not... 

Steroid alkaloids have been isolated from four families of terrestrial plant sources Solanaceae Uliaceae yipognaceae and Buxaceae) two animal sources Salamandra and PhjUobates and several marine sources. Steroid alkaloids can be classified based on stmcture and fall into a variety of categories. The spkosolanes contain a Q21 cholestane skeleton with a C20 spkoaminoketal moiety, as exemplified by the most abundant members of this class, veramine... 

It is to be noted that there is a difference in alkaloid content between the two subspecies oi Salamandra, namely, S. maculosa taeniata (S.m.t.) endemic to western Europe and 9. maculosa maculosa (S.m.m.) endemic to south-eastern Europe (3). An outline of the alkaloids and their occurrence in the two subspecies are given in Table I the table emphasizes the two groups of alkaloids which will be discussed in the following sections. 

Recent investigations concerning the biosynthesis of Salamandra alkaloids 17) involving in vitro and in vivo experiments showed that these alkaloids are formed like other steroids from acetate via cholesterol. The alkaloids substituted at C-17 (samandaridine, samandenone, and samandinine) might be considered as intermediates on the way from cholesterol (XXVIII) to the alkaloids without side chains. A cholic acid intermediate (XXIX) could be postulated as one route to the isopropyl... 

The synthesis of 20-methylpregn-5-ene-3j8,16/3-diol (94a) and its diacetate (94b) has been reported. The former compound was required as a possible intermediate for the synthesis of samandinine, a Salamandra minor alkaloid. Compound (95),... 

The synthesis of Salamandra alkaloids has been reviewed (K. Oka and S. Kara, Chem. Abs., 1979, 90, 187183 Oka, ibid., 1930, 3, 46951). The structure of cycloneosamandione has been revised to (23), with a "normal" A/B ring junction. The new formulation has been confirmed by a total synthesis, starting from oxime (24) which on Beckmann rearrangement afforded lactam (25) this was converted in four steps into... 

Steroidal Alkaloids of the Apocynaceae, Buxaceae, Asclepiadaceae, and of the Salamandra-Phyllobates Group... 

The synthesis of 3-benzoyl-A-homo-3-aza-5) -androstan-16-one (37), an analogue of the alkaloid samanine (36) from Salamandra maculosa, has been reported. Sodium borohydride reduction of the known compound (38) followed by tosylation alTorded the tosylate (39) the nitrile group was reduced by diborane and cyclized by benzoic anhydride-pyridine to the derivative (40a) similar cyclization with acetic anhydride-pyridine yielded the related acetamide (40b). This cyclization requires one equivalent of anhydride and the uncyclized amide is not an intermediate in the reaction. Jones oxidation of (40a) was followed by conversion into a benzylidene ketone derivative (41) with benzaldehyde-KOH in methanol. Reduction of (41) with sodium borohydride and acetylation furnished (42). Treatment of compound (42) with ozone followed by mild zinc reduction produced an acetoxy-ketone, which was further reduced by Zn-HBr-CH2Cl2 to the ketone (37). 

Synthetic studies in Salamandra alkaloids have been reported. In this work, attempted conversion into samandarine of compound (43), prepared from (38), failed. 

The Steroid Alkaloids The Salamandra Group by Gerhaed Habebmehl 427... 

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