Chemical and biological studies of Kalanchoe pinnata (Lam.) growing in Bangladesh

ABSTRACT

Objective: To isolate compounds from K. pinnata and elucidate their structures and to explore preliminary antioxidant, antimicrobial, cytotoxic and thombolytic activities of extractives of the plant. Methods: The methanol extract of whole plant of K. pinnata has been subjected to different chromatographic separation and purification processes to isolate the secondary metabolites. The structures of the isolated compounds have been elucidated by extensive NMR studies. The free radical scavenging activity of the crude extract and its different Kupchan fractions were determined on stable radical DPPH. In vitro antimicrobial activity was determined by the disk diffusion method. Cytotoxicity screening has been performed against Artemia salina. Total phenolics content, membrane stabilizing activity and thombolytic activities were assessed by following established protocol. Results: The isolated compounds were identified as glut-5(6)-en-3-one, taraxerone, 3β-friedelanol, β-amyrin-3-acetate, 3,5,7,3',5'-pentahydroxyflavone and β-sitosterol. The chloroform soluble fraction showed potent antioxidant activity of (IC50=80.0 μg/mL) and significant cytotoxicity, while the crude extract demonstrated noticeable total polyphenol content (149.24 mg of GAE/gm of extractive), moderate membrane stabilizing activity and inhibition of clot lysis of blood. Conclusions: The obtained results rationalize the folkloric use of the plant and can be further investigated to isolate the active compounds responsible for the biological activities.