Lupeol-type triterpenes

The pentacyclic triterpenes either comprise five anellated cyclohexane rings (oleanane type) or four cyclohexane rings connected with a cyclopentane ring (lupeol type. Fig. 114). These skeletons may carry a hydroxy group at C-3 (an exception are hopanoid-type compounds) and methyl groups at the positions 4, 8, 10, 14, 17, and 20 and in the case of lupeol-type compounds an isopropyl group at C-19. 

Sholichin M, Yamasaki K, Kasai R, Tanaka O (1980) C Nuclear magnetic resonance of lupane-type triterpenes, lupeol, betulin and betulic acid. Chem Pharm Bull 28 1006-1008... 

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