Terpenoids lupeol

Friedelin, lupeol and baurenol (all three terpenoids) were identified in the leaf bark of baobab. In addition, betulinic acid was isolated from the bark whereas the leaf exclusively yielded taraxerone and acetate of lupeol and baurenol (Odetokur, 1996, cited in (S)). 

Among the plant terpenoids with a lupane skeleton, lupeol is the simplest one and has recently been reported as the active principle of Crataeva religiosa (Capparidaceae). When it was tested on the habitual models of inflammatory response, it showed moderate activity on the carrageenan-induced rat hind paw and rat pleurisy [61]. A compound with a related structure is moretenol acetate, which was the most active of the triterpenes from Pluchea lanceolata (Asteraceae). When administered 50 mg/kg p.o., it inhibited by 55% the edema caused 3.5 h after carrageenan injection into rat hind paw [62]. At 100 mg/kg p.o. neolupenol, from the same plant, reached 55% inhibition at 2.5 h and 70% inhibition at 5 h [63]. 

Phytochemistry Leaves contain alkaloids, glycosides, bitter substances, sesquiterpene lactones (arctiopicrin and onopor-dopicrin), vitamin C and K, resins, titratable acids, sugars, tannins, terpenoids (taraxasteryl acetate), etc. Seeds contain alkaloids, acetates of lupeol and amyrin, and drying fatty oil (Khalmatov et al. 1984 Ul chenko et al. 1993 Khalilova etal.2004). 

Tri terpenoids Amyrin, lupeol (TMSi derivatives) Giilz et al., 1987... 

FIGURE 11.50 Betubnic acid and lupeol libraries. (From Pathak, A. et al., Synthesis of combinatorial libraries based on terpenoid scaffolds, Comb. Chem. High Throughput Screen, 5, 241, 2002 Srinivasan, T et al., Sobd-phase synthesis and bioevaluation of lupeol-based bbraries as antimalarial agents, Bioorg. Med. Chem. Lett, 12, 2803, 2002.)... 

Mostly, terpenoids originate from plants, but they are also synthesized by other organisms, including yeast and bacteria, as primary or secondary metabolites. Terpenoids are S5mthesized from two 5-car-bon building blocks that consist of isoprenoid units [62]. Based on the number of building blocks, terpenoids have been classified into four classes monoterpenes (geraniol, carvone, d-limonene, and perillyl alcohol), diterpenes (retinol and trans-retinoic acid), triterpenes (lupeol, oleanic acid, betulinic acid, and ursolic acid), and tetraterpenes (lutein, a-carotene, yS-carotene, and lycopene) [66]. 

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