Dienes triterpenoid

Regert et al. studied [9] a series of 30 Neolithic hafting adhesives from lake dwellings at Chalain (France) using an analytical procedure based on GC/MS analysis involving solvent extraction (dichloromethane) and trimethylsilylation. In the majority of the samples a series of triterpenoid compounds with a lupane structure was clearly identified on the basis of their TMS mass spectra. In particular, the presence of betulin, betulone, lupenone, lupeol and lupa-2,20(29)-dien-28-ol allowed birch bark tar to be identified. In other samples the co-occurrence of other plant biomarkers such as a-amyrin,(3-amyrin... 

Whereas empirical force-field calculations predict a ring A boat conformation for lanost-8-en-3-one, combined empirical force-field-extended Hiickel molecular orbital calculations favour a ring A chair conformation. Europium-shift n.m.r. results indicate that the molecule adopts the latter conformation. Studies on the peracetic acid-boron trifluoride etherate Baeyer-Villiger oxidation of 4,4-dimethyl-3-keto-triterpenoids to 5-lactones (18) and their subsequent ring contraction to y-lactones have been reported. Dehydrogenation of lanost-8-en-3j8-ol with 2,3-dichloro-5,6-dicyanobenzoquinone afforded, in addition to the corresponding 7,9(1 l)-diene, the aromatic seco-lanostane derivatives (19)... 

Epi-isomasticadienolalic acid (50) is a further new compound from Schinus molle. The galls of Pistacia palestrina contain several known compounds including 3j8-hydroxytirucalla-7,24-diene (see Vol. 8, p. 162). Structure (51) has been proposed for a triterpenoid from the fruits of Melia azedarach. The lack of an oxygen substituent at C-3 is unusual. Four new apotirucallol derivatives (52)—(55) have been isolated from the wood of Chisocheton paniculatus. ... 

The compounds (160),114 (161),115 and (162)116 have been prepared as possible intermediates for pentacyclic triterpenoid synthesis. Treatment of oleana-12,15-diene-3p,28-diol 3-acetate with toluene-p-sulphonyl chloride in pyridine affords the D(16a)-homo compound (163). The mechanisms of this and related reactions are discussed.117 2a,3[3-Diacetoxy-28-noroleana-12,17-diene has been synthesized.118... 

Dehydration of epoxides. When the triterpenoid epoxide (1), or the isomeric < -oxide, is refluxed with pyridine hydrochloride in pyridine it is converted in high yield into the diene (2). Use of hydrochloric acid in ethanol is attended with re-... 

Other common plant-derived triterpenoid acids, such as oleanolic and ursolic acid, exhibit weak antiinflammatory and antitumor activities, and studies have been directed at the synthesis of new analogues having increased potencies. These studies have led to the synthesis of 2-cyano-3,12-dioxoolean-l,9-dien-28-oic acid (CDDO) (54) and its methyl ester (55), which exhibit potent in vitro and in vivo antitumor activity against a wide range of tumors, including breast and pancreatic carcinomas and leukemias. ... 

Miyazaki and Yamada report that irradiation of cyclopentadiene in an argon matrix with a super-high-pressure Hg lamp results in the formation of bicyclo[2.1.0]pent-2-ene. By irradiation at shorter wavelengths the initial product is transformed into allylacetylene and vinylallene. The photochemical ring opening of the cyclohexadiene moiety within the triterpenoids (106) yields the corresponding trienes. The tricyclo[4.3.1.0]dienes (107) have been used as a source of some fluorocarbenes irradiation affords the carbenes with indane produced as the by-product. 

Taxonomy Cycloartane Triterpenoids The structure was corrected (see Cycloarta-16,24-dien-3p-ol). 

In addition, GA has also been suggested to possibly transactivate nuclear receptor peroxisome proliferator-activated receptor (PPAR) class of nuclear receptors triterpene compounds (such as 2-cyano-3,12-dioxooleana-l,9-dien-28-oic acid (CDDO) and dehydrotrametenolic acid) have been found to bind to and transactivate PPARy [25, 26]. This may suggest that GA, a triterpenoid compound, could also possibly transactivate (PPAR) class of nuclear receptors. 

Wang Y, Porter WW, Suh N, Honda T, Gribbles GW, Leesnitzer LM, Plunket KD, Mangelsdorf BDJ (2000) A synthetic triterpenoid,2-cyano-3,12-dioxooleana-l,9-dien-28-oic acid (CDDO), is a ligand for the peroxisome proliferator-activated receptor y. Mol Endrocrinol 14(10) 1550-1556... 

Triterpenoids and steroids are the major group of the lipid-accompanying substances in all natural lipids. Triterpenoids and steroids belong to a large group of compounds known as terpenoids or isoprenoids (through the oxidation or rearrangement modified terpenes). Six isoprene (2-methylbuta-1,3-diene) units... 

The triterpenoid 2-cyano-3,12-dioxooleana-l,9-dien-28-oic acid (CDDO) displays anti-tumour activity against a variety of cultured tumour cell lines and induces apoptosis of malignant human B cells ex vivo, including CLL cells. This compound and its more efficient imidazolide derivative are also active in a mouse model of CLL and analysis of blood cells recovered from treated mice showed that they are potent inducers of mmour cell death in vivo (Kress et al. 2007). Since CDDO is an... 

Arai, Y., K. Masuda, and H. Ageta Fern Constituents Eupha-7,24-diene and (20R)-Dammara-13(17),24-diene, Tetracyclic Triterpenoid Hydrocarbons Isolated from Polypodium Species. Chem. Pharm. Bull. (Japan) 30, 4219 (1982). 

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