The Structure of the Cactus Sterol Macdougallin (14α-Methyl-Δ⁸ -cholestene-3β,6α-diol). A Novel Link in Sterol Biogenesis^1,2

NMR spectra of 3β-hydroxy-5α-cholane derivatives, zymosterol synthesis intermediates

“…Selective fragmentation of the ion with mass 521 amu (MS mass 399 amu (consistent with the presence of a hydroxyl group and an epoxide ring), ions with mass 505 amu (elimination of the angular methyl as methane) and 475 amu (elimination of ethanol from the steroid side chain) were detected. The direction of the addition was based on the good availability of the α-side for attack and agreed with data for the epoxidation of related compounds [7][8][9]. Additional confirmation of the correctness of the configuration assignment came from the NOESY spectrum, where cross-peaks between angular methyls that were observed in the spectrum of diene IV were detected.…”

Chemistry, Biological Activities and In Silico Bioprospection of Sterols and Triterpenes from Mexican Columnar Cactaceae

“…In other studies, from roots of Peniocereus fosterianus and P. macdougallii were isolated two 3β, 6α-dihydroxysterol: peniocerol and macdougallin respectively, together with small amounts of lophenol and campesterol [45,47,48]. Special mention is made for macdougallin, which is a very particular 14α-methylcholesterol that will be discussed later.…”

“…The isolation of the sterols from Cactaceae began early with lophenol, schottenol, 24-methylene-lophenol, lathosterol, 5α-campest-7-en-3β-ol, spinasterol, together with locereol, and 5α-cholesta-8, 14-dien-3β-ol, which were isolated from aerial parts of Lophocereus schotii [42,43]. In a subsequent study, isolation of viperidinone and viperidone was reported, and deoxiviperidone from Wilcoxia viperina [44,45], species now called Peniocereus viperinus [46].…”

Ozonolysis of Unsaturated Carbonyl Compounds and Alcohols

“…Ozonolysis of 3β-acetoxy-5α-lanost-8-ene (68a) and 5α-lanost-8-en-3-ol (68ab) gave the corresponding epoxides 69a (47%) and 69b (56%) (Scheme 27). Ozone acts as epoxidating agent in the reaction with sterically hindered triterpenoids (70 → 71, Scheme 28) [28][29][30][31] and steroidal olefins [32,33]. These reactions cannot be interpreted in terms of the concerted Criegee mechanism.…”