ANTI-BACTERIAL ACTIVITY GUIDED PHYTOCHEMICAL INVESTIGATION ON THE ROOT BARK EXTRACT OF RUBIA CORDIFOLIA

Rubia cordifolia Linn is one of medicinal plants traditionally used for the treatment of various diseases and ailments by different people around the world. This study involves the successively extraction of the dried powdered root bark of R. cordifolia, evaluating the anti-bacterial activities, screening for phytochemicals, isolating and characterizing the chemical constituents from the crude with the best antibacterial activity. Freshly collected root bark of R. cordifolia was washed and then dried under shade at room temperature and grounded. The powdered root bark (175g) of R. cordifolia was successively extracted with (2.4L) chloroform/methanol(1:1) and (1.2L) methanol and the solution was filtered using Whatman filter paper and concentrated using rotary evaporator at temperature of about 400C. The (2.4L) chloroform/methanol (1:1) and (1.2L) methanol crude extract yields were 9.5% and 3.6%, respectively. The disc diffusion method was used to evaluate the antibacterial activity of the extracts. Phytochemical screening test of crude extracts revealed the presence of alkaloids, anthraquinones, glycosides, phenol, saponins, steroids, tannin and terpenoids whereas flavonoids were absent. A chloroform/methanol (1:1) crude extract which have shown relatively superior antibacterial activity and good TLC profile. This crude extract was subjected to column chromatography which resulted in the isolation of compound 1,3-dihydroxy-2-methoxymethyl-9,10-anthraquinone. Characterization of the isolated compound was performed using the spectroscopic techniques such as 1H-NMR, 13C-NMR and DEPT-135 and comparison with previously reported literature.