PHYTOCHEMICAL AND ANTIMICROBIAL ACTIVITIES ON THE STEM-BARK OF COMMIPHORA MOLLIS (Oliv.) Engl. (BURSERACEAE)

ABSTRACT

Commiphora mollis is traditionally used in the treatment of fever (malaria and typhoid) wound healing, cancer, ulcer and rheumatic condition. The plant grows in Nigeria and across Africa. Phytochemical analysis of methanol extract of the stem-bark of Commiphora mollis showed the presence of flavonoids, saponins, tannins, terpenoids and alkaloids. Extensive Phytochemical studies of ethylacetate water soluble fraction of methanol extract resulted in isolation (55 fractions, 100ml each were collected and pooled together based on similarities in their TLC profile to gave 8 major fractions and repeated gel filtration chromatography of Fraction 5 on Sephadex LH-20 packed column then preparative gave 7.5 mg of compound X1) and characterization using 1HNMR (9 proton signal 5 aromatic proton δ 7.0- 5.94 ppm, 2 oxymithine protons at 4.8 and 4.2 ppm and 2 methylene protons at 2.8 and 2.75 ppm), 13CNMR (15 carbon signals 12 in aromatic region, 2 oxymethine carbon and 1 methylene carbon.), DEPT (7 methine 1 methylene 1 quatenery ), 1H 1H COSY ( correlation between
protons at 7.0, H2’ // 6.83, H6’ 7.0, H2’ // 4.8, H2 6.83, H6’ // 4.8, H2 4.8, H2 // 4.2,

H3 4.8, H2 // 2.8, H4 4.2 , H3 // 2.8, H4 ), HSQC (correlation between proton and
carbon at 7.0, H2’ // 114, C2’ 6.83, H6’ // 118.10, C6’ 6.8, H5’ // 114.60, C5’ 5.8, H6 //
94, C6 4.82, H2 // 78.48, C2 4.21, H3 // 66.10, C3 2.8, H4 and 2.7, H4 // 27.84, C4 ),

HMBC and NOESY. The antimicrobial studies of the crude methanol extract, Chloroform and ethylacetate fractions were carried out using disc diffusion and broth agar dilution methods on clinical isolates of Corynebacterium ulcerans, Salmonella typhi, Proteus mirabilis, Bacillus sabtilis, Staphylococcus aureus, Streptococcus pyogens, Escherichia coli, Candida brusei, Shigella dysenteriae and Candida albicans. The crude methanol extract, chloroform and ethylacetate fractions showed strong inhibitory activity against all tested microoganisms with exception of Corynebacterium ulcerans, Salmonella typhi and Proteus mirabilis. Crude methanol extract was found to have MIC at 10 mg/ml for all organisms and variable value of MBC/MFC and that of chloroform and ethylacetate fractions have variable value for both MIC and MBC. The stem-bark of Commiphora mollis was rich in bioactive phytochemical which have antimicrobial activity and could serve as a potential source of compounds effective against disease causing micro- organisms.

CHAPTER ONE

1.0 INTRODUCTION

Natural products are the chemical compounds found in nature that usually have a pharmacological or biological activity for use in pharmaceutical drug discovery and drug design (Samuel, 1999). According to the World Health Organization (WHO), about 80 % of the world’s population relies on traditional medicine for their primary health care need (WHO, 2002). For thousands of years natural products have played a very important role in health care and prevention of diseases. The ancient civilizations of the Chinese, Indians and North Africans provide written evidence for the use of natural sources for curing various diseases (Phillipson, 2001).

Secondary metabolites are chemical compounds derived from living organisms. The study of natural products involves isolation in a pure form of these compounds and investigation of their structure. Secondary metabolites appear to function primarily in defense against predators and pathogens and in providing reproductive advantage as intraspecific and interspecific attractants. They may also act to create competitive advantage as poisons of rival species (Croteau, et al., 2000). Many plant terpenoids are toxins and feeding deterrents to herbivores or are attractants, and many possess pharmacological activity. Tannins, lignans, flavonoids, and some simple phenolic compounds serve as defenses against herbivores and pathogens, also many flavonoid pigments are important attractants for pollinators and seed dispersers.

The study of natural products has had a number of rewards. It has led to the discovery of a variety of useful drugs for the treatment of diverse ailments and contributed to the development of separation science and technology, spectroscopic methods of structure elucidation and synthetic methodologies that now make up the basics of analytical organic chemistry. One of the most important areas of application of natural products is in the treatment of human and veterinary ailments (Newman et al., 2000).

Although the use of natural products as medicinal agents presumably predates the first recorded history as the earliest humans used various, but specific plants to treat illness, the treatment of diseases with pure pharmaceutical agents is a relatively modern phenomenon.

For thousands of years medicine and natural products have been closely linked through the use of traditional medicines and natural poisons (Butler, 2004). Clinical, pharmacological, and chemical studies of these traditional medicines, which were derived predominantly from plants, were the basis of most early medicines such as aspirin (I), morphine (II), digitoxin (III) and pilocarpine (IV) (Butler, 2004).

The discovery of antibacterial filtrate “penicillin” by Fleming in 1928, re-isolation and clinical studies by Chain, Florey, and co-workers in the early 1940s, and commercialization of synthetic penicillins evolutionized drug discovery research (Butler, 2004). Following the success of penicillin, drug companies and research groups soon assembled large microorganism culture collections in order to discover new antibiotics. The output from the early years of this antibiotic research was prolific and included examples such as streptomycin (V), chloramphenicol (VI), chlortetracycline (VII), cephalosporin C (VIII), erythromycin (IX), and vancomycin (X) (Butler, 2004). All of these compounds, or derivatives thereof, are still in use as drugs today.