31-Norlanostenol

Optimization of Insecticidal Triterpene Derivatives by Biomimetic Oxidations with Hydrogen Peroxide and Iodosobenzene Catalyzed by Mn(III) and Fe(III) Porphyrin Complexes.[Pubmed:32644248]

Chem Biodivers. 2020 Sep;17(9):e2000287.

Semisynthetic functionalized triterpenes (4alpha,14-dimethyl-5alpha,8alpha-8,9-epoxycholestan-3beta-yl acetate; 4alpha,14-dimethyl-5alpha-cholest-8-ene-3,7,11-trione; 4alpha,14-dimethyl-5alpha-cholesta-7,9(11)-dien-3-one and 4alpha,14-dimethyl-5alpha-cholest-8-en-3beta-yl acetate), previously prepared from 31-Norlanostenol, a natural insecticide isolated from the latex of Euphorbia officinarum, have been subjected to oxidation with hydrogen peroxide (H(2) O(2) ) and iodosobenzene (PhIO) catalyzed by porphyrin complexes (cytochrome P-450 models) in order to obtain optimized derivatives with high regioselectivity. The main transformations were epoxidation of the double bonds and hydroxylations of non-activated C-H groups and the reaction products were 25-hydroxy-4alpha,14-dimethyl-5alpha-cholesta-7,9(11)-dien-3beta-yl acetate (59 %), 25-hydroxy-4alpha,14-dimethyl-5alpha-cholest-8-ene-3,7,11-trione (60 %), 4alpha,14-dimethyl-5alpha,7beta-7,8-epoxycholest-9(11)-en-3-one (22 %), 8-hydroxy-4alpha,14-dimethyl-5alpha-cholest-9(11)-ene-3,7-dione (16 %), 12alpha-hydroxy-4alpha,14-dimethyl-5alpha,7beta-7,8-epoxycholest-9(11)-en-3-one (16 %), and 4alpha,14-dimethyl-5alpha,8alpha-8,9-epoxycholestan-3beta-yl acetate (26 %), respectively. We also investigated the insect (Myzus persicae, Rhopalosiphum padi and Spodoptera littoralis) antifeedant and postingestive effects of these terpenoid derivatives. None of the compounds tested had significant antifeedant effects, however, all were more effective postingestive toxicants on S. littoralis larvae than the natural compound 31-Norlanostenol, with 4alpha,14-dimethyl-5alpha,8alpha-8,9-epoxycholestan-3beta-yl acetate being the most active. The study of their structure-activity relationships points out at the importance of C3 and C7 substituents.

Triterpene derivatives from Euphorbia enhance resistance against Verticillium wilt of tomato.[Pubmed:28027775]

Phytochemistry. 2017 Mar;135:169-180.

Oxidation of alpha-euphorbol and 31-Norlanostenol, two triterpenic compounds isolated from the latex of Euphorbia resinifera and Euphorbia officinarum respectively, yielded four products named 3beta-tosyloxy-4alpha,14alpha-dimethyl-5alpha-cholesta-7,9-diene; 4alpha,14alpha-dimethyl-5alpha-cholesta-7,9-dien-3beta-ol; 24-methylen-elemo-lanosta-8,24-dien-3-one and elemo-lanost-8-en-3,11,24-trione. They were evaluated for protection of tomato plants against Verticillium dahliae in a greenhouse. The four semisynthesized products were phytotoxic at higher concentrations as they completely inhibited tomato germination at 100 and 500 mug/ml. However at lower concentrations (10 and 50 mug/ml) germination and root length were not affected. Disease resistance against Verticillium wilt was assessed in tomato plants derived from seeds that germinated in the presence of 10 and 50 mug/ml of the four products. All of them were able to reduce significantly disease severity, with 10 mug/ml being more effective than 50 mug/ml. Reduction of leaf alteration index and of stunting index ranged from 52 to 68% and from 43 to 67%, respectively, while vessel discoloration was reduced by at least 95%. The compounds were also able to elicit H(2)O(2) accumulation before and after fungal inoculation and to significantly enhance peroxidase and polyphenol oxidase activities. These results suggest that the hemisynthetized triterpenes can be used as elicitors of disease resistance.

New Bioactive Semisynthetic Derivatives of 31-Norlanostenol and Obtusifoliol from Euphorbia officinarum.[Pubmed:27534104]

Nat Prod Commun. 2016 Jun;11(6):733-8.

Fifteen semisynthetic terpenoid derivatives from the major latex components of Euphorbia officinarum have been evaluated against the insect pest Spodoptera littoralis, two species of protozoan parasites, Trypanosoma cruzi and Leishmania infantum, and also against insect Sf9 and mammalian CHO cells to test their selective cytotoxicity. Our results showed that 40% of the test substances were postingestive toxicants to S. littoralis. All the tested derivatives had cytotoxic effects on insect-derived Sf9 cells, whereas mammalian CHO cells were affected by a lower number of compounds (47%). Furthermore, 87% of the test compounds had antiparasitic effects on both L. infantum and T. cruzi, with some of them being selective parasite toxicants.

Bioactive triterpene derivatives from latex of two Euphorbia species.[Pubmed:18304594]

Phytochemistry. 2008 Apr;69(6):1328-38.

We have investigated the antifeedant and toxic effects of 23 semisynthetic terpenoid derivatives obtained through chemical modifications of the major components of Euphorbia resinifera (alpha-euphol and alpha-euphorbol) and E. officinarum (obtusifoliol and 31-Norlanostenol) latex on several insect species (Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi), their selective cytotoxicity on insect Sf9 and mammalian CHO cells and their phytotoxic effects on Lactuca sativa. The conversions focused mainly on positions 3,7,11, and 24 with several oxidizing agents. A total of 18 compounds affected S. littoralis growth (IGR). Our results support the importance of the C-3 substituent, suggest the involvement of the C-7 substituent and indicate that the C-3 hydroxyl is not essential for the IGR effect. Overall, Sf9 cells were more sensitive to the active compounds than CHO cells. All of these compounds had non selective moderate phytotoxic effects on radicle elongation of L. sativa.

Analysis of methylsterol fractions from twenty vegetable oils.[Pubmed:1186450]

Lipids. 1975 Oct;10(10):634-40.

The 4-monomethylsterol and 4,4-dimethylsterol fractions were separated from the unsaponifiables of 20 vegetable oils by preparative thin layer chromatography, and their compositions were determined by gas liquid chromatography. Tentative identification of the individual components of these fractions was carried out by gas liquid chromatography and combined gas liquid chromatography-mass spectrometry. Among 4-monomethylsterols, obtusifoliol, gramisterol, and citrostadienol occur abundantly in most of the oils. Cycloeucalenol also occurs in some of the oils as a major component of 4-monomethylsterols. Other 4-monomethylsterols tentatively identified are: lophenol, 31-norlanosterol, 31-norcycloartenol, and 31-Norlanostenol and/or 4alpha-methylzymostenol. Among 4,4-dimethylsterols, cycloartenol and 24-methylenecycloartanol followed by beta-amyrin and cycloartanol are common to most of the oils. Butyrospermol, alpha-amyrin, lupeol, and cyclobranol together with a 4,4-dimethylsterol, presumably lanostenol, occur in some of the oils. Cyclolaudenol is present in poppy seed oil. Besides these compounds, each of the oils contains some unidentified members of 4-monomethylsterols and 4,4-dimethylsterols. The methylsterol fraction of capsicum seed oil as compared with that of the other oils is characterized by its very high content of lophenol and cycloartanol together with three other members, presumably 31-Norlanostenol, 4alpha-methylzymostenol, and lanostenol.