Green Synthesized Optically Active Organically Capped Silver Nanoparticles using Stem Extract of African Cucumber(Momordica charantia)

Silver nanoparticles (Ag NPs) were synthesized by a rapid facile plant-mediated green route. Sustainable and renewable stem extract of locally sourced African cucumber acted as reducing/capping agent, an alternative to toxic chemicals. The phytochemical screening indicated the existence of saponins and alkaloids in the stem extract of M. charantia. Unprecedented nucleation and growth of Ag NPs commenced within 5 minutes of the reaction. The mechanism of reaction was considered to be diffusion controlled Ostwald ripening process. Optical property of the as prepared Ag NPs was characterized by high intensity of absorption, revealed by narrow intense peaks, stipulating confinement of excitons.Surface Plasmon Band (SPB) of Ag NPs appeared at 400 - 460 nm. Photoluminescence (PL)excitation of the Ag NPs at 329 nm exhibited excitonic emission at 440 nm. The Ag NPs portrayed quasi-spherical shapes, with a mean size of 27.81 ± 1.64 nm from Transmission Electron Micrograph (TEM) measurement. XRD measurement showed peaks indexed to fcc Ag with a particle diameter of 25 nm, which corroborated TEM measurement. Elemental mapping of the nanoparticles showed an orientation of the Ag NPs, an evidence of capping by the biomolecules which stabilized the newly formed Ag NPs. Fourier Transformed Infra-red (FTIR) analysis showed the presence of hydroxyl groups (−OH) stretching, (−CH) stretching,C=C stretching and C−N group (in the phytochemicals) at 3237, 2913, 1620 and 1021 cm-1 respectively. It can be inferred that the as prepared Ag NPs is an optically active material

Room temperature Phytosynthesis of Ag/Co bimetallic nanoparticles using aqueous leaf extract of Canna indica

Continuous quest for safe environment has led to „green‟ approach of synthesizing nanoparticles. The method is easy, eco-friendly and cost-effective. Locally sourced medicinal plant Canna indica was used as capping/ stabilizing agent instead of toxic chemicals. Secondary metabolites in the plant extract acted as reducing agents. Optical measurements were carried out using Uv-vis spectrophotometer and photoluminescence (PL). Formation of core-shell was detected in the TEM micrograph, which was supported by two peaks observed in surface plasmon resonance shown in the Uv-vis spectra. FT-IR spectrophotometric analysis indicated the presence of some specific functional groups in the phytochemicals which were adsorbed on the surface of nanoparticles. This analysis depicted the presence of hydroxyl group (O-H stretching) with a broad strong peak at 3360 cm-1, C-H stretching at 2938 cm-1, C=C stretching at 1659 cm-1, C=N stretching at 1557 cm-1 and C-O deformation at 1065 cm-1. Crystalline phase of the nanoparticles was determined using X-ray diffraction (XRD). The plant-mediated green synthesized silver/cobalt nanoparticles are potential optical materials as a result of their broad absorption band and emissio

Pinus glabra: As a Potential Source of Anti- Mycobacterium tuberculosis Agent: Phytochemical and antimicrobial Studies of its Stem Extracts

With the increasing incidence of tuberculosis and rated second to HIV-AIDS by the World Health Organisation as a leading cause of death from infectious disease and increased resistance to drugs currently in use, there is therefore the need for alternative sources of drugs for the treatment of this disease. Pinus glabra presents as a potential candidate for such drugs discovery. Concoctions derived from the plant have been used to treat cases of rheumatism, cough, piles and catarrh. Sample extraction was performed by soaking the stem samples in ethanol for 172 h, which gave reddish-yellow oil after removal of the ethanol solvent. The oil was partitioned between 1:1 water/chloroform mixture. The aqueous layer was further partitioned separately with ethyl acetate and hexane. The phytochemical screening of the crude ethanol extract revealed the presence of alkaloids, saponins, tannins and flavonoids. Antimicrobial tests were performed on the crude ethanol extract, ethyl acetate and hexane fractions against clinical isolates Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella sp. by measurement of zones of inhibition. All test samples exhibited significant antimicrobial activity against the organisms albeit to different extent

Antimicrobial and Antioxidant properties of Petiveria alliacea

The leaf, stem and root decoctions of Petiveria alliacea (referred to as Anamu or Apacin (Guatemala), Guinea–Hen weed (English), Awogba or Ojusaju (Yoruba), kanunfari (Hausa) and Akwa-ose (Igbo) have been used as a diuretic, antispasmodic, sedative, analgesic and anti-inflammatory agents in traditional medicine. Cold maceration and Soxhlet extraction techniques were used to obtain oils from the leaf, stem and root of P. alliacea. The oils were analysed for their antimicrobial properties using brothmicrodilution technique while their antioxidant properties were determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) tests.The antimicrobial tests on the following micro-organisms Salmonella typhi, Staphylococcus aureus, Bacillus subtilis, Escherichia coli,as well as the anti-fungi test on Rhizopus sp., and Aspergillus niger, showed that the hexane and ethanol cold leaf extracts were most effective in limiting the growth of Salmonella typhi with minimum inhibitory concentration (MIC)value of 3.125 μg/mL and minimum bactericidal concentration (MBC)value of 6.25 μg/mL. The ethanol leaf extracts using Soxhlet extraction technique were most effective at MIC value of 3.125 μg/mL on Staphylococcus aureus, Escherichia coli. Likewise, the hexane and ethanolcold leaf extracts were most effective in limiting the growth of Rhizopus sp. and Aspergillus niger with MIC value of 3.125 μg/mL and minimum fungicidal concentration (MFC) value of 6.25 μg/mL

Antimicrobial and Antioxidant properties of Petiveria alliacea

The leaf, stem and root decoctions of Petiveria alliacea (referred to as Anamu or Apacin (Guatemala), Guinea–Hen weed (English), Awogba or Ojusaju (Yoruba), kanunfari (Hausa) and Akwa-ose (Igbo) have been used as a diuretic, antispasmodic, sedative, analgesic and anti-inflammatory agents in traditional medicine. Cold maceration and Soxhlet extraction techniques were used to obtain oils from the leaf, stem and root of P. alliacea. The oils were analysed for their antimicrobial properties using brothmicrodilution technique while their antioxidant properties were determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) tests.The antimicrobial tests on the following micro-organisms Salmonella typhi, Staphylococcus aureus, Bacillus subtilis, Escherichia coli,as well as the anti-fungi test on Rhizopus sp., and Aspergillus niger, showed that the hexane and ethanol cold leaf extracts were most effective in limiting the growth of Salmonella typhi with minimum inhibitory concentration (MIC)value of 3.125 μg/mL and minimum bactericidal concentration (MBC)value of 6.25 μg/mL. The ethanol leaf extracts using Soxhlet extraction technique were most effective at MIC value of 3.125 μg/mL on Staphylococcus aureus, Escherichia coli. Likewise, the hexane and ethanolcold leaf extracts were most effective in limiting the growth of Rhizopus sp. and Aspergillus niger with MIC value of 3.125 μg/mL and minimum fungicidal concentration (MFC) value of 6.25 μg/mL

Room temperature phytosynthesis of silver nanoparticles using leaf extract of Momordica charantia: optical and antimicrobial properties

Nigeria is endowed with rich diversity of medicinal plants whose potential as “green” reducing agents are under-utilized. As the world is advocating for safe environment, plant-mediated synthesis of nanoparticles is considered as an eco-friendly and sustainable synthetic route instead of using toxic chemicals. The method is fast, easy and cheaper compared with other conventional techniques. In this study, phytochemicals present in the leaf extract of indigenous Momordica charantia served as reducing, capping/stabilizing agents. The synthesized silver nanoparticles were characterized with Uv-vis spectrophotometer, photoluminescence (PL) and energy- dispersive x-ray spectrometer (EDX). Antimicrobial activities of the synthesized nanosilver were investigated on isolated Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa Candida albicans and Trichophyton rubrum. Optical measurement showed surface plasmon resonance with broad absorption peaks (400-450 nm). Significant growth inhibitions were also found at P <0.05 by means of analysis of variance SPSS tool. The leaf influenced nanosilver displayed highest activity on S. aureus, S. pyogenes and E. coli with MIC and MBC value of 12.5 mg/mL. Least activity was detected against P. aeruginosa (50 mg/mL MIC and 100 mg/mL MBC). From this work, the biogenic nature and optical properties displayed by the as-prepared nanosilver strongly suggest its applications as candidate for therapeutic drugs, diagnostic and medical imaging

ANTIBACTERIAL ACTIVITY OF MODERATELY VOLATILE COMPONENTS OF THE OIL EXTRACTED FROM THE SEEDS OF DACRYODES EDULIS G. LAM

Objectives: Dacryodes edulis is a versatile plant in many African countries, as its various parts are employed to treat several diseases. Like most plants used in traditional medicine, the possible mechanism by which D. edulis functions is still unknown. This study was designed to investigate the components of the plant seed with a view of justifying its use as traditional medicine. Methods: The seed oil of D. edulis was exhaustively extracted with a Soxhlet extractor from 500 g seeds and 200 g seeds of D. edulis using ethanol and petroleum ether as solvent, respectively. The extraction solvent was removed to obtain the oil which was then subjected to antimicrobial activity test to determine its activity against the following clinical isolates namely Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and Escherichia coli using gentamycin as positive control. Phytochemical screening and gas chromatography-mass spectrometry (GC-MS) analyses were carried out following standard methods Results: Ethanolic extract resulted in a higher percentage of oil yield (11.6%) than petroleum ether (5.3%). D. edulis seed oil showed remarkable activity against Gram-negative and Gram-positive isolates: E. coli, Bacillus spp, and S. aureus but not against P. aeruginosa. The presence of saponins, quinones, cardiac glycosides, terpenoids, and phenol was confirmed during qualitative phytochemical screening, and the preliminary results from GC-MS analysis show the presence of terpinen-4-ol, 4,6,6-trimethyl bicyclo[3.1.1]hept-3-en-2-one, ethyl 14-methyl-hexadecanoate, methyl 19-methyleicosanoate, squalene, C-14 to C-18 fatty acids, and their esters. Conclusion: The study, therefore, confirms that the use of D. edulis as component of traditional medicine may be justified

In-vitro Anti-Microbial Studies and GC/MS Analysis of the Leaf Extract and Fractions of Polyalthia longifolia (Engl. & Diels) Verde

Extensive studies show that secondary metabolites in plants, used for centuries in traditional medicine, offer new sources of drugs. In the traditional setting, extracts from various parts of the plant Polyalthia longifolia (mast tree) are used in treating several ailments but the components of these extracts, which would allow for meaningful dosage, are not known. We therefore decided to examine the antimicrobial activity by testing on selected microorganisms and identify the volatile components by gas chromatography-mass spectrometry of the leaf extracts of Polyalthia longifolia (mast tree). The crude leaf extract and fractions derived from the crude exhibited anti-microbial activity against two (2) bacteria and two (2) fungi. The chloroform fraction was very active against Salmonella typhi (13.00±0.82) when compared to fractions in other solvents. The GC-MS analysis showed that the extracts were composed fatty acids and their ester along with some long chain aldehydes, like hexadecenal and tetradecenal, and Caryophyllene and Aromandendrene. These chemical constituents may be responsible for the pharmacological and therapeutic activities of this plan

Antiplasmodial Activity shown by Secondary Metabolites Extracted from the Seeds ofPentaclethramacrophyllaBenth

Oil extracts from the African oil bean seed (PentaclethramacrophyllaBenth.) was analyzed for its phytochemical and mineral content and proximate, physicochemical and antimicrobial analyses were also performed. Phytochemical analysis showed the presence of tannins, saponins, quinones, terpenoids, phenols and coumarins in the oil sample. Mineral determination of the cotyledon showed the presence of iron (Fe) (with the highest concentration), Cu, Zn, Mn, Cr, Pb and Cd; while proximate analysis gave the following result: moisture (14.2%), ash content (1.5%), crude fibre (4.9%), crude proteins (12.8%), oil contents (4.9%), and carbohydrate (61.8%). GC-MS analysis of the partitioned petroleum ether and chloroform fractions of the oil revealed the presence of 9-Octadecenoic acid, 9,12- Octadecadienoic acid and their methyl esters,cis-9-Hexadecenal among the many components of the oil extract. Physicochemical analysis of the oil indicateda saponification value (148.67 mg KOH/g), peroxide value(8.0 meq/g), iodine value (10.41 mg iodine/g) and free fatty acid (8.98 mg KOH/g). The need for the development of new drugs for malaria led to our study of the antiplasmodial activity of the oil from the seeds of Pentaclethramacrophylla. Toxicological studies were carried out to determine the LD50with chloroquinediphosphate as positive control and normal saline as negative control. Using the Peter’s 4 day suppressive test a parasite inhibition rate of 47.72% (25 mg/kg), 63.63% (50 mg/kg) and 61.36% (100 mg/kg) on day 4 after treatment was recorded. A 95.45% chemo-suppression was observed for animals treated with 10 mg/kg chloroquine. This resultis an indication that the extract had appreciable signs of chemosuppression