Euphorbol

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 H2O2 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.

Two new lanostane triterpenoids from the branches and leaves of Polyalthia oblique.[Pubmed:24914904]

Molecules. 2014 Jun 6;19(6):7621-8.

Two new lanostane triterpenoids, 20-hydroxyEuphorbol-7-one (1) and 15alpha-hydroxyEuphorbol-7,11-dione (2), together with four known triterpenoids, Euphorbol-7-one (3), friedelin (4), stigmast-4-ene-6alpha-ol-3-one (5), stigmasta-4-en-3,6-dione (6), were isolated from ethanol extract of the branches and leaves of Polyalthia obliqua. The structures of 1 and 2 were elucidated on the basis of extensive spectroscopic analysis and comparisons with related known compounds. Antibacterial activities of two new compounds and four known compounds were tested.

Antileishmanial and antitrypanosomal activity of triterpene derivatives from latex of two Euphorbia species.[Pubmed:21950160]

Z Naturforsch C J Biosci. 2011 Jul-Aug;66(7-8):360-6.

The in vitro activity on Leishmania infantum promastigotes and Trypanosoma cruzi epimastigotes of 25 semisynthetic terpenoid derivatives has been evaluated. These compounds were obtained through chemical modifications of the major components of Euphorbia resinifera (alpha-euphol and alpha-Euphorbol) and Euphorbia officinarum (obtusifoliol and 31-norlanosterol). Leishmaniasis and Chagas' disease are major worldwide health problems. The drugs of choice for their treatment are still problematic in both cases, and therefore there is an urgent need to discover new drugs with high activity and low side effects. Natural products have become a key source of new drugs in the last years. The genus Euphorbia has been the subject of abundant phytochemical and pharmacological research because of its potential medical applications, but the antiparasitic effects of derivatives from plants of this genus are still unknown. Our results showed that 76% and 64% of the test compounds had antiparasitic effects on L. infantum and T cruzi, respectively. The different activities on both parasites, especially their moderate effects on mammalian cells, indicate an interesting selective toxicity.

[Chemical constitutents in fermental mycelium of Xylaria nigripes].[Pubmed:18831203]

Zhongguo Zhong Yao Za Zhi. 2008 Jun;33(11):1269-72.

Nine known compounds, 5-hydroxy-7-methoxy-2-methyl-4-chromanone (1), 5, 7-dihydroxy-2-methyl-4-chromanone (2), 5-hydroxyl-2-methyl-4-chromanone (3), 1-(2, 6-dihydroxyphenyl)-3-hydroxybutanone(4), 5alpha, 8alpha-epidioxyergosta-6, 22-dien-3beta-ol (5), (22E,24R)-ergost-7, 22-dien-3beta, 5alpha, 6alpha-triol (6), Euphorbol (7), beta-sitosterol (8) and 2-(4-hydroxyphenyl) -ethanol (9) were isolated and identified in Xylaria nigripes for the first time, and their structures were mainly determined by MS and NMR methods. Compounds 1 and 2 were isolated as the natural product for the first time.

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.

Eupha-7,9(11),24-trien-3beta-ol ("antiquol C") and other triterpenes from Euphorbia antiquorum latex and their inhibitory effects on Epstein-Barr virus activation.[Pubmed:11858748]

J Nat Prod. 2002 Feb;65(2):158-62.

The structures of three triterpene alcohols isolated from the latex of Euphorbia antiquorum were established to be eupha-7,9(11),24-trien-3beta-ol (2; antiquol C), 19(10-->9)abeo-8alpha,9beta,10alpha-eupha-5,24-dien-3beta-ol (3; antiquol B), and 24-methyltirucalla-8,24(24(1))-dien-3beta-ol (4; Euphorbol) on the basis of spectroscopic methods. Compounds 3 and 4 have previously been assigned the erroneous structures of 10alpha-cucurbita-5,24-dien-3alpha-ol and 24-methyleupha-8,24(24(1))-dien-3beta-ol, respectively. Compounds 2-4 and four other known compounds isolated from the latex, euphol (1), lemmaphylla-7,21-dien-3beta-ol (5), isohelianol (6), and camelliol C (7), showed potent inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA).

Pneumocysterol [(24Z)-ethylidenelanost-8-en-3beta-ol], a rare sterol detected in the opportunistic pathogen Pneumocystis carinii hominis: structural identity and chemical synthesis.[Pubmed:9874778]

Proc Natl Acad Sci U S A. 1999 Jan 5;96(1):97-102.

Pneumocystis carinii pneumonia (PcP) remains among the most prevalent opportunistic infections among AIDS patients. Currently, drugs used clinically for deep mycosis act by binding ergosterol or disrupting its biosynthesis. Although classified as a fungus, P. carinii lacks ergosterol. Instead, the pathogen synthesizes a number of distinct Delta7, 24-alkylsterols, despite the abundance of cholesterol, which it can scavenge from the lung alveolus. Thus, the pathogen-specific sterols appear vital for organism survival and proliferation. In the present study, high concentrations of a C32 sterol were found in human-derived P. carinii hominis. The definitive structural identities of two C-24 alkylated lanosterol compounds, previously not reported for rat-derived P. carinii carinii, were determined by using GLC, MS, and NMR spectroscopy together with the chemical syntheses of authentic standards. The C31 and C32 sterols were identified as Euphorbol (24-methylenelanost-8-en-3beta-ol) and pneumocysterol [(24Z)-ethylidenelanost-8-en-3beta-ol], respectively. The identification of these and other 24-alkylsterols in P. carinii hominis suggests that (i) sterol C-24 methyltransferase activities are extraordinarily high in this organism, (ii) 24-alkylsterols are important components of the pathogen's membranes, because the addition of these side groups onto the sterol side chain requires substantial ATP equivalents, and (iii) the inefficacy of azole drugs against P. carinii can be explained by the ability of this organism to form 24-alkysterols before demethylation of the lanosterol nucleus. Because mammals cannot form 24-alkylsterols, their biosyntheses in P. carinii are attractive targets for the development of chemotherapeutic strategies against this opportunistic infection.