Kola nut is a native stimulant which is commonly chewed in many West African cultures, individually or in a group setting. It is often used ceremonially and to honour guest. Phytochemical analysis and antibacterial sc...Kola nut is a native stimulant which is commonly chewed in many West African cultures, individually or in a group setting. It is often used ceremonially and to honour guest. Phytochemical analysis and antibacterial screening of red and white Cola nitida (kola nut) extracts were evaluated using qualitative and quantitative method. Thin layer chromatography (TLC) was used to evaluate the phenolic content. Antibacterial screening was done using agar well diffusion method against odontopathogens;(Lactobacillus sp., Corynebacterium haemolyticum, Proteus vulgans, Bacillus lentus, Streptococcus anginosus and Pseudomonas aeruginosa) obtained from stock cultures. Phytochemical screening revealed the presence of alkaloids, flavonoids, saponin, tannins, glycoside, steroids, volatile oil and balsams. Higher content of alkaloids, saponin and glycoside was obtained in the aqueous extract than the methanol for both red and white kola nut. The results of TLC analysis revealed the presence of quercetin and coumarin in red kola and keamferol and coumarin in white kola respectively. The result of antibacterial activity of red C. nitida showed a zone of inhibition of 18 mm and 23 mm at 60 mg/ml for aqueous extract on Proteus vulgans and Streptococcus anginosus. Similarly white kola inhibited the growth of S. anginosus at 90 mg/ml with a zone of 18 mm. Methanol extract of red kola inhibited the growth of P. vulgans and S. anginosus at 60 mg/ml with a zone of 16 mm and 20 mm respectively. Acetone and ethyl acetate extracts of both red and white kola nut did not show any activity against the tested organism at all concentrations. The results obtained indicate that C. nitida which posses promising chemotherapeutic and antibacterial potentials respectively that could be useful against odontopathogens. The study may serve as baseline for further studies.展开更多
A new potential approximation known as modified Becke-Johnson based on density functional theory is applied to compute the electronic band profile and optical response of CdIn2O4, CdGa2O4 and CDAl2O4 compounds. The di...A new potential approximation known as modified Becke-Johnson based on density functional theory is applied to compute the electronic band profile and optical response of CdIn2O4, CdGa2O4 and CDAl2O4 compounds. The direct band gap with common LDA, GGA and EV-GGA is drastically underestimated compared with modified 13ecke-Johnson approximation, whose results are significantly closer to the experimental findings. The optical properties like dielectric constant, refractive index, reflectivity, optical conductivity and absorption coefficient axe also computed. A unique characteristic associated with cation replacement is studied; the replacement of cation In by Ga and Ga by AI significantly reduces the direct energy band gap in these compounds. This variation is of crucial importance for band gap dependent optical properties of these compounds, which is also proof for applications of these compounds in optoelectronic devices.展开更多
文摘Kola nut is a native stimulant which is commonly chewed in many West African cultures, individually or in a group setting. It is often used ceremonially and to honour guest. Phytochemical analysis and antibacterial screening of red and white Cola nitida (kola nut) extracts were evaluated using qualitative and quantitative method. Thin layer chromatography (TLC) was used to evaluate the phenolic content. Antibacterial screening was done using agar well diffusion method against odontopathogens;(Lactobacillus sp., Corynebacterium haemolyticum, Proteus vulgans, Bacillus lentus, Streptococcus anginosus and Pseudomonas aeruginosa) obtained from stock cultures. Phytochemical screening revealed the presence of alkaloids, flavonoids, saponin, tannins, glycoside, steroids, volatile oil and balsams. Higher content of alkaloids, saponin and glycoside was obtained in the aqueous extract than the methanol for both red and white kola nut. The results of TLC analysis revealed the presence of quercetin and coumarin in red kola and keamferol and coumarin in white kola respectively. The result of antibacterial activity of red C. nitida showed a zone of inhibition of 18 mm and 23 mm at 60 mg/ml for aqueous extract on Proteus vulgans and Streptococcus anginosus. Similarly white kola inhibited the growth of S. anginosus at 90 mg/ml with a zone of 18 mm. Methanol extract of red kola inhibited the growth of P. vulgans and S. anginosus at 60 mg/ml with a zone of 16 mm and 20 mm respectively. Acetone and ethyl acetate extracts of both red and white kola nut did not show any activity against the tested organism at all concentrations. The results obtained indicate that C. nitida which posses promising chemotherapeutic and antibacterial potentials respectively that could be useful against odontopathogens. The study may serve as baseline for further studies.
文摘A new potential approximation known as modified Becke-Johnson based on density functional theory is applied to compute the electronic band profile and optical response of CdIn2O4, CdGa2O4 and CDAl2O4 compounds. The direct band gap with common LDA, GGA and EV-GGA is drastically underestimated compared with modified 13ecke-Johnson approximation, whose results are significantly closer to the experimental findings. The optical properties like dielectric constant, refractive index, reflectivity, optical conductivity and absorption coefficient axe also computed. A unique characteristic associated with cation replacement is studied; the replacement of cation In by Ga and Ga by AI significantly reduces the direct energy band gap in these compounds. This variation is of crucial importance for band gap dependent optical properties of these compounds, which is also proof for applications of these compounds in optoelectronic devices.
