Betulinic acid (3[beta],hydroxyl-lup-20(29)-en-28-oic acid) (Compound 1 in Scheme-1) is a lupane-structured pentacyclic triterpene that can be obtained from many fruits, plants, and vegetables, and higher amounts can be extracted from birch tree bark (Betula species), sycamore and eucalyptus bark, the bark of planes (Platanus species), and chemical or enzymatic oxidation of betulin
(extracted in large amounts from white birch tree bark) [1-4].
The main triterpenes that offer efficacy in this extract are betulin
, betulinic acid, lupeol and betulinic caffeates.
nutans contains important constituents such as phenolics, flavonoids, stigmasterol, [beta]-sitosterol, lupeol, betulin
, chlorophyll derivatives, protocatechuic acid, C-glycosyl flavones, vitexin, isovitexin, shaftoside, isomollupentin, 7-O-[beta]-glucopyranoside, orientin, isoorientin, cerebrosides, steroids, triterpenoids, glycerides, monoacylmonogalactosylglycerol, and sulfur-containing glucosides.
is the precursor of betulinic acid shown in figure 1.
Attenuation of quorum sensing controlled virulence factors and biofilm formation in Pseudomonas aeruginosa by pentacyclic triterpenes, betulin
and betulinic acid.
macrostachyus stem bark are lupeol, betulin
, and fatty acids .
Wang, "Novel betulin
derivative induces anti-proliferative activity by G2/M phase cell cycle arrest and apoptosis in Huh7 cells," Oncology Letters, vol.
The major principle phytochemical constituents of Clinacanthus nutans are stigmasterol, [beta]-sitosterol, lupeol, betulin
, six known Cglycosyl flavones, vitexin, isovitexin, schaftoside, isomollupentin, 7-O-[beta]-gluco pyranoside, orientin, isoorientin, two glycoglycerolipids, a mixture of nine cerebrosides and a monoacylmonogalactosylglycerol, and five sulfur-containing glucosides .
Another polyphenol, betulin
, was also reported to alleviate ethanol-induced alcoholic liver injury via the SIRT1-AMPK signalling pathway to enhance lipophagy .
 isolated betulin
1, lupeol 2, crotepoxide 3, [beta]-sitosterol 4, and stigmasterol 5 from stem barks and twigs of C.
In addition, in vitro and in vivo studies suggest that betulin
has anticarcinogenic properties and induces apoptosis in different tumor cells including human squamous cell carcinoma (SCC) cells [28-31].