David Akinpelu

Obafemi Awolowo University | OAU · Department of Microbiology

Studies on the synthesis of some sulfa quinoxaline has generate a considerable reputation as a result of their outstanding biochemical properties. This recent study was designed to prepared some sulfa quinoxaline hydrazone derivatives and studying their antimicrobial potency. The 3-methyl-2-oxo-1,2-dihydroquinoxaline-6-sulfonohydrazone derivatives...

Population-based studies of Staphylococcus aureus contribute to understanding the epidemiology of S. aureus infection. We enrolled surgical inpatients admitted to an African tertiary-care hospital in order to prospectively analyze the nosocomial impact of S. aureus. Data collection included an active sampling of the anterior nares and infectious fo...

Aims: This studies aims at the synthesis of new heterocyclic systems and study its biological and pharmacological properties. Objective: This study was designed to synthesized some quinoxaline-2,3-dione with sulfonamide moiety, characterize the synthesized compounds, and study the antimicrobial properties of the synthesized compounds on some bacter...

Aims: This studies aims at the synthesis of new heterocyclic systems and study its biological and pharmacological properties. Objective: This study was designed to synthesized some quinoxaline-2,3-dione with sulfonamide moiety, characterize the synthesized compounds, and study the antimicrobial properties of the synthesized compounds on some bacter...

Aims: This aims of this study was to synthesis new quinoxaline-based heterocycles and study its antibacterial properties. Objective: This study was designed to synthesis some 3-methyl-6-nitroquinoxaline-2-one with hydrazine moiety, characterize the synthesized compounds, and study their antibacterial properties on some bacterial strains. Materials...

The review article attempts to give recent advances on quinoxaline and its derivatives. Some pathways to the synthesis of quinoxaline, quinoxaline-2-one and quinoxaline-2,3-dione were reported using simple reactive quinoxaline synthon. In addition, the reactions, biological and technological applications of derivatives of quinoxaline and related co...

Aims: This aims of this study was to continue the effort to synthesis new quinoxaline-based heterocycles and study its antibacterial properties. Objective: This study was designed to reacts 3,6-dimethylquinoxaline-2-hydrazine with some substituted aromatic ketones and study their antibacterial properties on some locally and clinically isolated bact...

This study investigated antimicrobial properties of Alchornea cordifolia leaf extract against a panel of selected bacterial strains. It also assessed antioxidant and phytochemical properties of the plant constituents responsible for the bioactive actions recorded. The antimicrobial potentials of the crude extract along with the fractions obtained w...

Background and objectives Annona squamosa (A. squamosa) is a medicinal plant, used in ethnomedicinal treatment of various ailments. However, there is a dearth of information on the chemical constituents of this plant’s fruit pod and chemical parameters of the seed oil. The objectives of this study were, therefore, to determine the chemical characte...

The study investigated the wound healing potential of leaf extract of Terminalia avicenniodes in vivo models of Wistar rats. The antimicrobial potential of the plant extract was first determined against a panel of pathogens associated with wound infection using agar-well dilution method. Thirty healthy male Wistar rats weighing 180±2.8 g were anaes...

Objective: Investigations were carried out on cidal effects of crude extract and fractions obtained from stem bark of Psidium guajava against a panel of 74 strains of Escherichia coli and Shigella dysenteriae implicated in diarrhea and dysentery infections. Methods: Powdered sample of the stem bark was extracted in methanol/distilled water (3:2) an...

Objective: Investigations were carried out on cidal effects of crude extract and fractions obtained from stem bark of Psidium guajava against a panel of 74 strains of Escherichia coli and Shigella dysenteriae implicated in diarrhea and dysentery infections. Methods: Powdered sample of the stem bark was extracted in methanol/distilled water (3:2) an...

Background and objective Compositae species are applied as whole or part of the feed stock for animals and poultry. However, rabbits display varied preferences in their consumption of these plants, following the order of: Melanthera scandens (MS) > Synedrella nodiflora (SN) > Aspilia africana (AA) > Ageratum conyzoides (AC). This preference profile...

We investigated the antimicrobial activities of Tectona grandis Linn. Leaf extract against selected bacterial strains as well as its antioxidant potentials with a view to obtaining bioactive components with antibacterial properties. Fresh leaves of T. grandis which was harvested from Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife,...

Background and Objectives Medicinal plants are the richest, cheapest and most readily available source of drugs, nutraceuticals and food supplements. Pharmaceutical industries still rely largely on medicinal plants for intermediates due to their chemical diversities. This study, therefore, investigated the chemical constituents, thermal decompositi...

Aims: To investigate the chemical composition and antibacterial activity of essential oil isolated from flowers of Moringa oleifera (MO) grown in Western Nigeria. Methodology: Gas chromatography–mass spectrometry (GC-MS) analysis was carried out for identification and determination of the phytochemical constituents of the oil. Standard microbiologi...

The incidence of resistance to commonly used antimicrobial agents by microbial pathogens demands increased effort in the development of effective ways of treating infections and diseases. The n-hexane fraction of lyophilized crude bark extract of Parkia biglobosa (Jacq.) was prepared and, in combination with selected antibiotics, assayed for antimi...

Objective: To evaluate the interactions between the crude extracts of Cocos nucifera (C. nucifera) and six front line antibiotics (ampicillin sodium salt, penicillin G sodium, amoxicillin, chloramphenicol, ciprofloxacin and tetracycline hydrochloride), against some bacterial pathogens linked with human infection. Methods: The pulverized husk of C....

Anacardium occidentale stem bark was air-dried, ground and soxhlet extracted with methanol (CH3OH). Phytochemical screening of the extract revealed the presence of alkaloids, saponins, tannins, anthraqinones, flavonoids and cardiac glycosides. The extract was partitioned with: n-hexane, ethyl acetate (EtOAc) and CH3OH to afford respective fractions...

Objective: This study investigates the antibacterial activity, antioxidant potential and major classes of phytochemicals of eight Nigerian plant parts used in combination by traditional healers in Nigeria to treat cancer. Methods: The antibacterial activity was estimated by determination of the zone of inhibition and minimum inhibitory concentratio...

Background Staphylococcus aureus causes variety of infections in humans and animals worldwide and predominates in surgical wound infections. This study assessed the antimicrobial potential of the stem bark extract of Chrysophyllum albidum against an array of vancomycin resistant Staphylococcus aureus (VRSA) isolated from clinical samples. Methods...

Background: The incidence of resistance to the existing antibiotics by microorganisms demand increased effort in the development of new antibiotics for the treatment of microbial infections and diseases. Infections due to multidrug resistant pathogens are difficult to manage due to relatively limited choices of antimicrobial agents. This study inv...

A galactose-specific lectin purified from the skin mucus of African catfish (Clarias gariepinus) was tested for antimicrobial activities against microbial pathogens isolated from the catfish pond water with a view to examining the involvement of the protein in the host defense mechanism. Standard methods of microbial isolation and identification we...

Alchornea laxiflora leaf extract was tested against a range of microorganisms using standard microbiological methods for antimicrobial activities. The extract inhibited the growth of all the bacterial and 15 fungal isolates tested. The zones of inhibition exhibited against the test bacteria ranged between 12 mm and 24 mm and between 11 mm and 24 mm...

The study investigates the in vitro antibacterial potentials of stem bark extracts of Persea americana on strains of Bacillus cereus implicated in food poisoning. The crude stem bark extracts and butanolic fraction at a concentration of 25 mg/mL and 10 mg/mL, respectively, exhibited antibacterial activities against test isolates. The zones of inhib...

Chalcones are natural biocides. Several publications appear every year covering the synthesis of chalcones because they exhibit an array of pharmacological activities. In this study, some condensation reactions of 1-Indanone with substituted benzaldehydes were carried out under different reaction conditions. The chalcone products were converted to...

A methanolic crude extract of Parkia biglobosa was prepared and later partitioned in succession with different solvents of increasing polarity ranging from n-hexane, chloroform and ethyl acetate to butanol. Phytochemical screening of the extract revealed the presence of alkaloids, tannins, saponins, flavonoids, steroids, glycoside and sugars. The i...

Background/aim: Quinazolinone derivatives are well-known for their diverse pharmacological activities. For example, methaqualone is used as a sedative-hypnotic drug. One common method of synthesizing quinazolinones utilizes the condensation of anthranilamide with structurally diverse carbonyl compounds. In this present study, the aim is to carry ou...

Twelve phenylglyoxylic acid derivatives were synthesized, characterized and investigated for their antibacterial activity against nine Gram-positive and four Gram-negative bacterial isolates. Some of the synthesized compounds exhibited broad spectrum activity against the bacterial strains, with 2-[2-(acetylamino)phenyl]-N-(2-chlorophenyl)-2-oxoacet...

Twelve phenylglyoxylic acid derivatives were synthesized, characterized and investigated for their antibacterialactivity against nine Gram-positive and four Gram-negative bacterial isolates. Some of the synthesizedcompounds exhibited broad spectrum activity against the bacterial strains, with 2-[2-(acetylamino)phenyl]-N-(2-chlorophenyl)-2-oxoacetam...

Antimicrobial resistance among pathogenic organisms is now a persistent problem and of tremendous public health care concern around the globe. These pathogens are able to develop mechanisms of resistance, the antimicrobial agents that were at one time the drug of choice. They continue to develop various mechanisms of resistance either by intrinsic...

The increasing numbers of cases of antibiotic resistance among pathogenic bacteria such as Vibrio species poses a major problem to the food and aquaculture industries, as most antibiotics are no longer effective in controlling pathogenic bacteria affecting these industries. Therefore, this study was carried out to assess the antibacterial potential...

Infection due to multidrug resistance pathogens is difficult to manage due to bacterial virulence factors and because of a relatively limited choice of antimicrobial agents. Thus, it is imperative to discover fresh antimicrobials or new practices that are effective for the treatment of infectious diseases caused by drug-resistant microorganisms. Th...

To investigate the antidiabetic properties of aqueous extract of stem bark of Afzelia africana (A. africana) and its beneficial effect on haematological parameters in streptozotocin induced diabetic rats. A total of 30 rats including 24 diabetic and 6 normal rats were used for this study. Diabetes was induced in male Wistar rats by intraperitoneal...

The in vitro antilisterial activities and time kill regimes of crude aqueous and n-hexane extracts of the husk fiber of Cocos nucifera were assessed. The aqueous extracts were active against 29 of the 37 test Listeria isolates while the n-hexane extracts were active against 30. The minimum inhibitory concentrations (MICs) of all the susceptible bac...

This study investigated the anti-Vibrio activities of the leaf extract of Dialium guineense on eighteen environmental strains of vibrios. The phytochemical constituents of the extract were also assayed in a preliminary test. The results showed that D. guineense crude leaf extract exhibited anti-Vibrio activities on fourteen out of eighteen environm...

Objective: To investigate the antidiabetic properties of aqueous extract of stem bark of Afzelia africana (A. africana) and its beneficial effect on haematological parameters in streptozotocin iunsdeudc efodr dthiaibs esttiuc drya.t sD. iMabeettheosd ws:a sA i ntodtualc eodf 3i0n rmatasl ein Wcluisdtianrg r a24ts d biayb ientitcra apnedri t6o nneoa...

Objective: To investigate the antidiabetic properties of aqueous extract of stem bark of Afzelia africana (A. africana) and its beneficial effect on haematological parameters in streptozotocin iunsdeudc efodr dthiaibs esttiuc drya.t sD. iMabeettheosd ws:a sA i ntodtualc eodf 3i0n rmatasl ein Wcluisdtianrg r a24ts d biayb ientitcra apnedri t6o nneoa...

We assessed the antibiotic production potentials of ten putative Streptomyces strains isolated from the Nahoon beach and their antibacterial activities against a wide range of bacteria including reference strains, environmental strains and clinical isolates. The minimum inhibitory concentrations (MICs) of the crude ethyl acetate extracts ranged fro...

A total of 84 culturable marine actinomycetes belonging to 15 generic morphotypes were isolated from water and rock scrapings from the Nahoon beach, a coastal shore of Indian Ocean in the Eastern Cape Province of South Africa. The colonies showed diverse morphological characteristics and their occurrence and distribution varied with sample type. Th...

Antioxidant agents of plants origin have continued to attract interest because of the potential they hold in the maintenance of human health accompany with their minimal side effects. In this study, the antioxidant activity of the crude methanolic stem bark extract of Afzelia africana was investigated using the scavenging activities on superoxide a...

Crude extracts of three actinomycetes species belonging to Saccharopolyspora (TR 046 and TR 039) and Actinosynnema (TR 024) genera were screened for antibacterial activities against a panel of several bacterial strains. The extracts showed antibacterial activities against both gram-negative and gram-positive test bacteria with inhibition zones rang...

Summary: The phytochemical screening and antimicrobial potentiality of Phyllanthus amarus against multidrug resistant pathogens were investigated using standard microbiological techniques. The extracts were tested by agar well diffusion method for activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella Spp. i...

A simple and efficient method has been developed for the synthesis of various 2-quinoxalinone-3-hydrazone derivatives using microwave irradiation technique. The series of 2-quinoxalinone-3-hydrazone derivatives synthesized, were structurally confirmed by analytical and spectral data and evaluated for their antimicrobial activities. The results show...

Jatropha curcas and Newboulda laevis are medicinal plants used for the treatment of ailments such as diarrhoea, dysentery, sexually transmitted diseases, jaundice and several other diseases caused by micro-organisms. The antibacterial activities of the leaves of the plants were assessed against a panel of selected bacterial pathogens. Methanolic le...

We had recently reported antibacterial activity in the crude extract of the stem bark of Afzelia africana (Akinpelu et al., 2008). In this study, we assessed the biocidal and cell membrane disruption potentials of fractions obtained from the crude extract of the plant. The aqueous (AQ) and butanol (BL) fractions exhibited appreciable antibacterial...

In vitro antimicrobial activities of crude extract of Garcinia kola was investigated against some bacterial isolates comprising of both Gram-positive and Gram-negative organisms. The methanolic crude extract exhibited significant inhibitory action against eleven out of fifteen bacterial isolates tested at a final concentration of 20 mg/ml. The zone...

Afzelia africana is used in folklore remedies for the treatment of diarrhoea, gastrointestinal disorders and gonorrhoea among other ailments; hence we assessed the in vitro antimicrobial activities of this important medicinal plant. Thirty bacterial isolates as well as four fungal isolates were tested in this study. The crude extract of the stem ba...

Some quinoxaline derivatives 1-8 were synthesized and screened in-vitro for their growth inhibitory activity against nine strains of Gram-positive and four strains of Gram-negative bacteria. Some of the compounds exhibited broad spectrum (in vitro) activity against the bacterial strains. One of the compounds, 2,3-dioxo-1,2,3,4-tetrahydroquinoxaline...

In vitro antibacterial activities of four fractions of stem bark of Distemonanthus benthamianus Baill. against some bacterial isolates implicated in oro-dental infections were investigated using standard microbiological methods. The aqueous and chloroform fractions exhibited significant inhibitory action against all twelve bacterial isolates tested...

The in vitro antibacterial activity of crude methanolic extract of the seeds of Garcinia kola was investigated. The extracts exhibited antibacterial activities with zones of inhibition ranging from 10 mm to 25 mm. The minimum inhibitory concentration of the diethyl ether fraction was between 0.313 and 5.0 mg/ml, while that of butanol fraction varie...

The antibacterial potentials of Erythrophleum suaveolens against some selected bacterial isolates were investigated. The aqueous and chloroform fractions of the plant extract exhibited significant inhibitory action against eight of the twelve bacterial isolates tested at a concentration of 10 mg mL<SUP>-1</SUP>. The zones of inhibition exhibited by...

The antimicrobial activity of the hexane, ethyl acetate and methanol extracts of the leaves of Terminalia catappa, and the oil fractions from the hexane extract (TC1-TC5), were examined. Thirteen different bacterial and two fungal isolates were used. The results show that all the solvent extracts exhibited activity at concentrations ranging from 0....

The leaves extracts of Urena lobata L were examined for their antioxidant, antibacterial and antifungal activities. Preliminary evaluation of both the crude and the solvent fractions showed a broad spectrum of activity since the extracts inhibit the growth of both gram positive and gram negative bacterial isolates. The ethyl acetate and n-butanol f...

In south-western part of Nigeria Psidium guajava and Mangifera indica are commonly used for herbal preparations in the treatment of toothache, gastrointestinal disorders, dynsentery, diarrhoea, sore gums and sore throats. This has, therefore, led to the investigation of the antimicrobial activities of methanolic extracts of P. guajava and M. indica...

The in vitro antimicrobial activity of the hexane, ethyl acetate and methanol extracts of the leaf of Tithonia diversifolia , and one sesquiterpene lactone 1 isolated from the ethyl acetate extract was studied. Of the fourteen strains of bacteria used, the ethyl acetate extract was the most active, showing inhibitory activity against five Gram +ve...

The in vitro antimicrobial activity of the hexane, ethyl acetate and methanol extracts of the leaf of Tithonia diversifolia, and one sesquiterpene lactone 1 isolated from the ethyl acetate extract was studied. Of the fourteen strains of bacteria used, the ethyl acetate extract was the most active, showing inhibitory activity against five Gram +ve a...

The synthesis of some quinoxalinesulfonyl derivatives is described. Two of the synthesized derivatives, 2-oxo-1,2-dihydroquinoxaline-6-sulfonyl azide (3a) and 2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonyl azide (3b), were screened in vitro for their growth inhibitory activity against nine strains of Gram-positive and seven strains of Gram-nega...

Anacardium occidentale bark 60% methanolic extract exhibited antimicrobial activity against 13 out of 15 bacterial isolates at a concentration of 20 mg/ml.

Piliostigma thonningii stem bark 60% methanolic extract exhibited activity against six out of eight bacterial isolates at a concentration of 20 mg/ml.

Bryophyllum pinnatum leaf 60% methanolic extract was found to inhibit the growth of five out of eight bacteria used, at a concentration of 25 mg/ml.

Nicotiana tabacum leaf 60% methanolic extract exhibited antibacterial activity against six out of nine bacterial isolates at a concentration of 25 mg/ml.

Bridelia ferruginea fruit 60% methanolic extract exhibited antimicrobial activity against seven out of eight bacterial isolates at a concentration of 20 mg/ml.

Vernonia amygdalina leaf 60% methanol extract was found to be active at 25 mg/ml against six out of eight bacterial isolates.

In south-western part of Nigeria Psidium guajava and Mangifera indica are commonly used for herbal preparations in the treatment of toothache, gastrointestinal disorders, dynsentery, diarrhoea, sore gums and sore throats. This has, therefore, led to the investigation of the antimicrobial activities of methanolic extracts of P. guajava and M. indica...