Olean-12-ene

The inhibitory effect of olean-12-ene-3p,23,28-triol tri-O-hemiphthalate sodium (158), ursolic acid (210), and betulinic acid (257) on lung tumors have been reported [43]. Lantadene B (134), on oral administration, has an inhibitory effect on mouse hepatic tumors induced by A-nitrosodiethylamine and phenobarbital [45],... 

Olean-12-ene-2a,3 3,23-triol 159 Commiphora merkeri (Burseraceae) roots CAR [149]... 

Allylic methoxylation is the first step in the anodic oxidation of olean-12-ene alcohols 83 78a). The electrolysis of erythrodiol 83a in an MeOH—AcONa—(C) system forms a mixture of 84a (28%) and 85a (55%). The alcohols 84 can be exclusively converted into 85 on treatment with a p-TsOH-aq. dioxane system at 25 °C for 30 min (Scheme 3-31). 

Maniladiol (= Olean-12- ene-3P,16P-diol) (triterpene) Helianthus annuus (Asteraceae) CHY (-100 pM) [105]... 

The use of lanthanide-induced shifts allows distinction between C-29 and C-30 methyl signals in the oleanane and ursane series.91 The 13C resonances of several olean-12-enes have been assigned.92 Experimental verification of Ruzicka s... 

Pachysandiol B (109) and pachysonol (110), two new friedelin derivatives, have been isolated from Pachysandra terminalis Rearrangement of the corresponding 3-en-16-one followed by WolfT-Kishner reduction yielded 18) H-olean-12-ene. Roxburghonic acid (111) from the leaves of Putranjiva roxhurghii is a C-25 carboxylic acid. " The full paper on pachysandiol A has appeared. ... 

Olean-12-enes are converted into the corresponding 12-chloro-derivatives, e.g. (121), on reaction with a gaseous mixture of nitrosyl chloride and chlorine in pyridine solution. This method has been used to separate natural mixtures of oleanenes and ursenes since the latter are inert under these conditions. The glycyrrhetic acid derivative (122) afforded the fluorinated product (123) on treatment with CF3OF at —70 °C. (123) decomposed readily in polar solvents to give a rearranged product which has been assigned the novel structure (124). 

Details have been published of the biosynthesis of olean-12-ene and urs-12-ene type triterpenoids in tissue cultures of lsodon japonicus (Labiatae).10 The results are fully in accord with the original biogenetic postulates of Ruzicka and his colleagues.11 By using [5-13C, 5-2H2]MVA as substrate it was shown that, as expected, both squalene 2,3-epoxides [part structures (12) and (13)] are involved in the biosynthesis of 2a-hydroxyursolic acid (14), 3-epimaslinic acid (15), and j3-sitosterol in I. japonicus. The 13C n.m.r. spectra of (14) and (15) suggested... 

The two main triterpene dialcohols in olive oil are erythrodiol (homo-olestranol, 5a-olean-12-ene-3 3,28-diol) and uvaol (A-12-ursen-3(>,28-diol) (Figure 9.7). 

---