Maslinic acid from

Cloves contain about 2% of the triterpene, oleanolic acid. Narayanan and Natu (1974) isolated maslinic acid from clove buds. From clove, 2a-hydroxyoleanolic acid was isolated by Brieskorn et al. (1975). 

Licania heteromorpha var. heteromorpha Bentham is a tree up to 30 m high native to the Amazonian forest. Phytochemical study of its aerial parts yielded both triterpenes and flavonoids triterpenes were obtained from the chloroform extract by silica gel column followed by RP-HPLC and were characterised as betulinic acid (11), alphitolic acid (48), 3(3-0-trans-p-coumaroyl alphitolic acid (49), 3(3-0-cw-p-coumaroyl alphitolic acid (50), 3 -0-trans-p-coumaroyl maslinic acid (51), 3fi-O-cis-p-coumaroyl maslinic acid (52), 3(3-0-tnms,-/ -coumaroyl-2a-hydroxy-urs-12-en-28-oic acid (53), 3 3-0-m-p-coumaroyl-2a-hydroxy-urs-12-en-28-oic acid (54) [see Fig. (2) and (6)] [15], Compounds 11 and 48-54 were identified comparing their H and 13C NMR data with those previously described. Triterpenoids 48-54 were found for the first time in Licania, while betulinic acid had been isolated previously from L. carii [9]. On the other hand, flavonoids were isolated from the chloroform-methanol and methanol residues by Sephadex LH-20 and HPLC they were identified as myricetin 3-0- 3-D-galactopyranoside (17), myricetin 3-0-a-L-rhamnopyranoside (32), myricetin 4 -methylether-3-0- 3-D-glucopyranoside (55), myricetin 4 -methylether-3-0-a-L-rhamnopyranoside (45), myricetin 3,4 -di-0-a-L-rhamnopyranoside (56), myricetin 7-methylether 3,4 -di-0-a-L-rhamnopyranoside (57), and myricetin 4 -methylether-3-0- 3-D-galactopyranoside (58) [see Fig. (2), (4), and (6)]. The last three myricetin derivatives were new natural compounds [16]. Known compounds were identified by comparison of their H and l3C NMR spectra with those reported in the literature [15]. 

In the oleanane-ursane group of triterpenes, postulated hydride shifts [as proposed by Eschenmoser and co-workers (1955)] have now been demonstrated. Incorporation of [4- C]MVA into oleanolic acid (56), ursolic acid (63), and several other metabolites was accomplished with tissue cultures of Isodon japonicus (Lamiaceae). Following introduction of [4- C]mevalonate and [l,2- C2]acetate, the pentacyclic triterpene compounds were examined by C-NMR spectroscopy. Rings D and E were formed by the routes predicted by Eschenmoser et al. (1955). The labeling pattern at carbons 4,23, and 24 of 3- p/-maslinic acid (64) indicates that this series is formed from (35)-squalene epoxide, rather than from the (3R)-epimer. 

Other nonphenolic compounds have also been extracted from olive leaves such is the case with terpenic acids including oleanolic, ursolic, and maslinic acids, which were extracted by Albi et al. [259]. Both maceration and Soxhlet extraction using hexane as extractant were used to remove terpenic dialcohols, triglycerides, a-tocopherol, ester waxes, squalene, and (3-carotene, among other substances [260]. The extraction efficiency was similar, the differences between the two methods never exceeding 5%. 

Triterpene amount within triter-pene dry extracts (TEs) from various plant materials. BA, betulinic acid (6) BE, betulin MA, maslinic acid (82) OA, oleanolic acid (30) and UA, ursolic acid (87). From Jager et al. [15], 2009 by the authors with permission of Molecular Diversity Preservation international, Basel, Switzerland. 

An industrial procedure has been established for fhe isolation of 2a,3p-dihydroxy-olean-12-en-28-oic acid (maslinic acid, 82) on a large scale, sfarfing from olive fruifs Olea europaea) [62]. Maslinic acid was bioconverfed by Cunninghamella blakesleana... 

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