Chemical Constituents of Rumex abyssinicus Roots and Evaluation of Its Antimicrobial Activities

Abstract

Medicinal plants are usually screened for phytochemicals that may lead to its further isolation, purification and characterization of active principles. The roots of Rumex abyssinicus is used traditionally in Ethiopia for treating different diseases such as hepatitis, hemorrhoids, gonorrhea, typhus and wound. Thus, this study was conducted to investigate the phytochemicals and in-vitro antimicrobial activity extracts of the roots of R. abyssinicus. The roots were collected, chopped and air dried under shade in the Laboratory. Then, the dried plant material was subjected to sequentional extraction using maceration technique by soaking 1 kg of the sample in petroleum ether, chloroform, acetone and methanol and concentrated under reduced pressure using rotary evaporator. The crude extracts were dried and exposed to antimicrobial activity test using four bacterial and two fungal strains. Based on its antimicrobial activity, the acetone crude extract was used for column chromatographic isolation. Herein, two anthraquinones were isolated and characterized: chrysophanol and emodin. Its microbial activity was evaluated for potential antimicrobial activity against medically important strains by the agar disc diffusion method. The concentration of the crude extracts and isolated compounds was 100 mg/mL tested against S. aureus ATCC25903, K. pneumoniae NCTC13368, E. coli ATCC 25722, P. aeruginosa DSMZ 1117 and C. albicans and S.cerevisiae. The zone of growth inhibition of extracts and isolated compounds were compared with standard drugs like Gentamycin and Mancozeb. The results showed that isolated compounds (1 and 2) have demonestrated higher bacterial growth inhibition than the crude extracts. However, compound 2 was not actıve againist the S. cerevisiae strain.