Betulinic acid methyl ester is a lupane-type triterpenoid and an esterified version of betulinic acid that has been found in Helicteres hirsuta and has diverse biological activities.[1],[2],[3],[4],[5] It inhibits HIV-1 reverse transcriptase (IC50 = 11 μM).[1] Betulinic acid methyl ester is active against L. braziliensis and T. cruzi (IC50s = 69.9 and 93.3 μM, respectively).[2] It induces melanogenesis in (EC50 = 2.5 μM) and inhibits the growth of B16 2F2 melanoma cells in vitro (IC50 = 4.9 μM).[3] Betulinic acid methyl ester is cytotoxic to SK-LU-1, HepG2, HeLa, SK-MEL-2, and AGS cells (IC50s = 60.84, 77.43, 80.17, 66.17, and 69.94 μg/ml, respectively).[4]
Reference:
[1]. Akihisa, T., Ogihara, J., Kato, J., et al. Inhibitory effects of triterpenoids and sterols on human immunodeficiency virus-1 reverse transcriptase. Lipids 36(5), 507-512 (2001).
[2]. Domínguez-Carmona, D.B., Escalante-Erosa, F., García-Sosa, K., et al. Antiprotozoal activity of betulinic acid derivatives. Phytomedicine 17(5), 379-382 (2010).
[3]. Hata, K., Hori, K., and Takahashi, S. Differentiation- and apoptosis-inducing activities by pentacyclic triterpenes on a mouse melanoma cell line. J. Nat. Prod. 65(5), 645-648 (2002).
[4]. Quang, D.N., Pham, C.T., Le, L.T.K., et al. Cytotoxic constituents from Helicteres hirsuta collected in Vietnam. Nat. Prod. Res. 34(4), 585-589 (2020).
[5]. Eyong, K.O., Bairy, G., Eno, A.A., et al. Triterpenoids from the stem bark of Vitellaria paradoxa (Sapotaceae) and derived esters exhibit cytotoxicity against a breast cancer cell line. Med. Chem. Res. 27(1), 268-277 (2017).