Abstract

Phytochemical and in-vitro biological study of Psidium guajava L. leaves cultivated in Egypt

Fathy M. Soliman, Magda M. Fathy, Maha M. Salama, Engy A. Mahrous and *Fatema R. Saber

ABSTRACT

The Egyptian guava tree (Psidium guajava Linn.) is a member of the Myrtaceae family. In this study, seven compounds were isolated from chloroform: methanol (80:20) extract (CME) of Psidium guajava L. leaves; namely two flavonoids; Quercetin-3-O-α-arabinofuranoside (Avicularin) and Quercetin-3-O-β-xylopyranoside (reynoutrin), two meroterpenoids; Psiguadial D and Psidial C in addition to β-sitosterol, 4-hydroxy phenyl ethanoid palmitate ester and Corosolic acid. The structures of the isolated compounds were elucidated on the basis of their spectral data; MS, UV, 1D and 2D NMR analyses. The CME of P. guajava leaves showed a moderate free radical scavenging activity with IC50= 92.26 μg/mL, as compared to ascorbic acid (19.76 μg/mL) in DPPH-based assay. Furthermore, the in vitro α- glucosidase
inhibitory activity of the CME was measured using p-nitrophenyl-α- glucopyranose (p-NPG) and a potent inhibitory activity was observed (IC50= 31.6±0.06 μg/mL) relative to acarbose (224±2.31 μg/mL), a reference antidiabetic drug. Moreover, the extract exhibited cytotoxic activity against HEPG2, MCF7 and HEP2 cell lines with (IC50= 19.3, 20.6, 17.5 μg/mL), respectively. The major isolated compounds; Psiguadial D, and Corosolic acid exhibited cytotoxic activity against MCF7 with IC50 = 22.1 & 10.4 μg/mL respectively

Keywords: Psidium guajava, Myrtaceae, meroterpenoids, Corosolic acid, antidiabetic, cytotoxic.