ISOLATION AND CHARACTERIZATION OF BIO-ACTIVE COMPOUNDS FROM STEM BARK EXTRACT OF UAPACA PILOSA HUTCH
ABSTRACT
Uapaca pilosa(Hutch.) a plant used in some parts of Africa in the treatment ofdysentery, menstrual pain, fever, constipation, erectile dysfunction, skin infections, female sterility, pile, rheumatism, emetic, tooth-troubles and fatigue. The dried plant was extracted, the extract was subjected tophytochemical investigation using standard method revealed the presence of alkaloids, flavonoids, anthraquinones, tannins, saponins, steroids, terpenoids and glycocides. Extensive silica gel column chromatography of the ethylacetate fraction of the stem bark extract, the most active of all the fractions, led to the isolation of two compounds GF1 and GF2. Their identities were determined by analysis of their spectral data using FTIR, 1D and 2D NMR. The structures of the compounds were supported by comparing their spectral data with the literature. GF1 was found to be betulin while GF2 was found to be beta-sitosterol. The antimicrobial screening of the crude extract and fractions using agar well diffusion methodshowed activity againstStaphylococcus aureus, Shigella dysenteriae,Salmonella typhii, Bacillus subtilisandEscherichia coli. The Zone of Inhibition of theplant extract against selected microorganisms ranges from 13mm to 17mm against
Staphylococcus aureus,10mm to 14mm againstBacillus subtilis,12mm to 15mmagainstShigella dysenteriae,15mm to 18mm againstEscherichia coliand 10mm to 11mm againstSalmonella typhii. The MIC and MBC for the extract, fractions and isolated compounds were also determined. The range of Minimum Inhibitory concentration is between 6.25 mg/mL to 25 mg/mL forStaphylococcus aureus,25 mg/mL forShigella dysenteriae,6.25 mg/mL forBacillus subtilisand 12.50 mg/mL for
Escherichia coliwhile the Minimum Bactericidal Concentration range between 12.50mg/mL forStaphylococcus aureus, 50 mg/mL forShigella dysenteriae,12.50 mg/mL forBacillus subtilisand 25 mg/mL forEscherichia coli. This study on the stem bark
extract fromUapaca pilosa, used traditionally in some parts of Africa as a medicinal plant for the treatment of various ailments has confirmed that it has antimicrobial activity against the microbes that cause some of these diseases.
CHAPTER ONE
INTRODUCTION
Over the years the world traditional medicine has been known to take its source from higher plants and their extracts in the treatment of diseases and infections (Sofowora, 1983). Until 19th century, when the development of chemistry and synthetic organic chemistry started, medicinal plants were the sources of active materials used in healing and curing human diseases. Before the advent of modern methods of producing drugs, medicinal plants such asAllium sativum,Azadirchata indicaandCitrus limonumwere used in treating both malaria and typhoid fever. Also some plant leaves were used in treating skin rashes and to heal wounds. Likewise, modern pharmaceuticals rely heavily on these medicinal plants for their raw materials such as cocoa leaves and opium plant from papaver species for analgesics. The active principles of plants differ from one plant to another due to the diversity in biological activities (Sofowora, 1983; Kubmarawaet al.,2007; Krishnaiahet al., 2009).
Traditional medicinal practice has been established for centuries in many parts of the world. Numerous plants and herbs are used globally by traditional medicine practitioners. The practice is known to vary from one country to another (Sofowora, 1984). Extracts from the various plant parts (leaves, stem bark and roots) of various higher plants are used in herbal medicine production (Sofowora, 1983, 1984, 1993). Plants` extracts are given singly or as concoctions for the treatment of various ailments. In actual sense more than 75% of the world population depend on these various forms of concoctions and herbal decoctions for the treatment of infections (Robenson and Zhang, 2011).
Comments are closed.