Antioxidant and Antimicrobial Activities of β-Caryophyllene dominated Leaf Essential oil of Trichilia monadelpha (Thonn.) JJ De Wilde

Trichilia monadelpha (Thonn) JJ De Wilde (Meliaceae) is an essential plant of diverse medicinal uses in folk medicine. It is deployed in the treatment of ulcers/epidermal infections, epilepsy, gonorrhea and inflammatory disorders such as arthritis etc. This study investigated the leaf essential oil constituents of T. monadelpha along with the corresponding antioxidant and antimicrobial activities. The essential oil of fresh leaves of T. monadelpha was isolated by hydrodistillation using all glass Clevenger distillation apparatus while the identification and characterization was done by Gas Chromatography-Mass Spectrometry (GC-MS). Antioxidant activity was carried out by scavenging effect on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) at 517nm in a UV-Visible spectrophotometric assay with  Ascorbic acid,  Butylated hydroxylanisole (BHA) and α-Tocopherol as reference standards. Antimicrobial assay was examined by Agar diffusion method. A total of fifteen compounds were identified in the essential oil with β-Caryophyllene (35.41%) as the major constituent. The oil demonstrated moderate inhibition against seven of the ten microorganisms used for the assay, namely: Staphylococcus aureus, Esherichia coli, Bacillus subtilis, Pseudomonas aerugunosa, Candida albicans, Aspergillus niger, Rhizopus stolonifer. The antioxidant activity of the essential oil (IC50 of 3.72 mg/ml) though lower than that of ascorbic acid (IC50 of 1.47 mg/ml) and BHA (IC50 of 1.88 mg/ml) was however better than that of α-Tocopherol (IC50 of 4.83 mg/ml).The results obtained corroborated the uses of Trichilia monadelpha in folk medicine. Keywords: Gas Chromatography-Mass Spectrometry, Essential oil, β-Caryophyllene, Antioxidant and Antimicrobial Activities. DOI: 10.7176/JNSR/11-16-05 Publication date:August 31st 202

Synthesis, Microbial Growth and Oxidation Inhibitory Properties of Three Mannich Bases

Diseases, infections and unhealthy diet serve as threat to human existence. Bases obtained from Mannich reaction have been found to have pharmacological application as antioxidant, antimicrobial, anti-cancer, anti-hypertensive, antiviral and anti-inflammatory in drugs and as food additives. Biologically active 4-(3-oxo-1,3-diphenyl propylamino) benzoic acid (A1), N-phenyl-3-(phenylamino) propanamide (A2) and 3-(p-tolylamino)-N-phenylpropanamide (A3) were synthesized and their purity confirmed by melting point determination and Thin layer chromatography. Characterization of the Mannich bases by spectroscopic methods: Infrared and Ultraviolet spectroscopy confirmed the presence of C=O, O-H, N-H typical of Mannich bases. They are also readily soluble in organic solvents. Antioxidant activity of A1, A2 and A3 involving the use of 2,2- diphenyl-1-picrylhydrazyl radical (DPPH) and hydrogen peroxide was significant when compared with antioxidant standards: ascorbic acid, butylatedhydroxylanisole and α-tocopherol. Compounds A2 and A3 gave percentage inhibition of 90.37 and 90.11 at 0.0625 mg/ml in the hydroxyl radical scavenging activity, a better percentage inhibition than ascorbic acid and α–tocopherol at the same concentration. Antimicrobial activity of the three compounds against bacterial and fungal strains; Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomona aeruginosa, Klebsiellae pneumoniae, Salmonellae typhi, Candida albicans, Aspergillus niger, Rhizopus stolonifer and Penicillium notatum showed moderate microbial inhibition when activity was compared with standard drugs: gentamicin and tioconazole for bacteria and fungi respectively. The ionization constant (pKa) values at 6.01, 8.15 and 7.23 reported for compounds A1, A2 and A3 respectively indicates that they would be readily metabolized at physiological pH. Keywords: Mannich bases; spectroscopy; oxidation; antimicrobial; ionization constan

Phytochemical composition and antioxidant and antimicrobial activities of Pergularia daemia

Background: Pergularia daemia of the Asteraceae family has wide use in ethno-medicine. It is established to have pharmacologicall activity with potential medicinal significance as an antifungal, antioxidant, antimicrobial, antiinflamatory, analgesic, fertility, hepatoprotective and antic ancer agent. Aim: This study estimated the qualitative and quantitative amount of of phytochemicals in Pergularia daemia plant and the and antioxidant capacity was also determined. Setting: The fresh plants of P. Daemia were collected from Ido-Ekiti, Ekiti State, Nigeria and was identified at Plant Biology Department of the University of Ilorin, Nigeria. The samples were air-dried, pulverized and stored properly for investigation. Method: Both qualitative and quantitative phytochemical analyses of the leaves and stem were determined through n-hexane, ethyl acetate and ethanol extracts of P. daemia. Antioxidant activities of the extracts were evaluated with 2,2-diphenyl-1-picryhydroxyl (DPPH). The antibacterial and antifungal assay of the extracts were determing by dissolving 1 mg of the extract in 5 mL of the extracting solvent to give a 200 µg/mL solution. Results: Flavonoids, steroids, terpenoids and glycosides were present in all the stem and leaf extracts of P. daemia. The total phenolic content of the extracts ranged from 15.898 ± 0.111 mgGA/g to 54.679 ± 0.675 mgGA/g. The leaf has higher concentration of flavonoids than the stem and the ethanol extracts contain highest content of flavonoids. The concentration of the ethanol extract of the leaf was 400.196 mg QE/g while that of ethyl acetate and n-hexane were 388.627 mg QE/g and 338.725 mg QE/g respectively at 10 mg/mL. Ethanol extracts has the highest concentration of phenolic compounds, flavonoids and antioxidant capacity. Conclusion: The results derived from this study validate the ethno-medicinal use of the aerial parts of P. daemia

Variation in chemical composition, insecticidal and antioxidant activities of essential oils from the leaves, stem barks, and roots of Blighia unijugata (Baker) and B. sapida (K. D. Koenig)

Blighia unijugata (Baker) and B. sapida (K.D. Koenig) (Sapindaceae) are forest trees widespread in Tropical Africa. They are used in folk medicine for the treatment of rheumatism, cardiovascular diseases, yellow fever, dysentery, and epilepsy. The essential oils of the air-dried leaves, stem bark, and roots of the plants were extracted using the hydrodistillation method and were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method using α-tocopherol and ascorbic acid as standards. The insecticidal activity of the oils was investigated by determining the percentage mortality of the grain insects (Sitophilus zeamaise). Results showed that the yield of the colorless oils (% w/w) from the leaves, stem bark, and roots of the plants were 0.91%, 0.42%, and 0.34% for B. unijugata and 0.67%, 0.32%, and 0.48% for B. sapida, respectively. The most abundant compounds in B. unijugata leaves were pentadecanoic acid (14-methyl-, methyl ester) (38.34%), carbonic acid, propyl-en-2-yl undecylpropyl ester (36.79%), and 9-octadecanoic acid (Z)-methyl ester (24.86%). The stem bark was rich in 1,3-dimethoxybenzene (79.01%) while the root contained limonene (20.51%), trans-13-octadecanoic acid (16.74 %), and cis-vaccenic acid (9.50%). The leaf essential oil of B. sapida had hexahydrofarnesyl acetone (21.43%), phytol (20.45%), geosmin (16.258%), and α-ionone (8.271%) as the major constituents. The stem bark had cholesterol (38.66%) as the major constituent while the root contained nonanal (18.09%) and 4-cyclopropyl carbonyl tetradecane (11.6%). The antioxidant analysis revealed that B. unijugata root had 83.96% inhibition at 100 mg/ml, while B. sapida stem had 79.73% inhibition, better than α-tocopherol. No significant insecticidal activity was observed in the essential oils of the plants against S. zeamaise except for B. sapida stem which showed 50% toxicity to the maize weevils. However, the two plants can be the source of antioxidant agents against oxidative stress and related diseases

Monoterpene diol, iridoid glucoside and dibenzo-<i>α</i>-pyrone from <i>Anthocleista djalonensis</i>

Anthocleista djalonensis has provided a new monoterpene diol, djalonenol, as well as the known iridoid glucoside djalonenoside (also sweroside). Also isolated for the first time from a plant source is a dibenzo-α-pyrone, djalonensone, previously identified as a fungal metabolite. The structure of the new compound was elucidated on the basis of its chemical and spectral data as tetrahydro-3-hydroxymethylene-4-(3-hydroxymethylene prop-1-ene)-2H-pyran-2-one

Diterpenoids from the stem bark of Croton megalocarpoides Friis & M. G. Gilbert

Five previously undescribed compounds, megalocarpoidolide I (1), megalocarpoidolide J (3), 12-epi-crotonzambefuran A (4), megalocarpoidolide K (5), 1-trans-p-hydroxycoumaroyl–geranylgerani-1-ol (6) were isolated from the stem bark of Croton megalocarpoides Friis & M. G. Gilbert. The known ent-trachyloban-18-ol, megalocarpoidolide B, megalocarpoidolide C (2), megalocarpoidolide H, crotocorylifuran, 7,8-dehydrocrotocorylifuran, 1,2-dehydrocrotocorylifuran-2-one, acetyl aleuritolic acid, lupeol, N-trans-p-coumaroyl-3′,4′-dihydroxyphenylethylamine, dodecyl trans-ferulate and lignoceryl trans-ferulate were also isolated. The structures of the compounds were determined using NMR, IR spectroscopy and HRMS. The structure of compound 1 was determined using Logic for Structural Determination (LSD). Compounds 1, 2 and 3 that were selected for screening based on their ability to add diversity to the NCI small molecule compound collection, were evaluated against the NCI60 panel of human tumour cell lines at 10μM level but found to be inactive