Oluwole B. Familoni

Phenolic contents, antioxidant and antibacterial activities of Hymenocardia acida.

This study investigates the antioxidant and antibacterial activities of aqueous and methanolic extracts from Hymenocardia acida Tul. (Hymenocardiaceae). The inhibition values of the extracts and quercetin were found to be very close, with no significant differences at a concentration of 0.05 mg mL−1 in their ability to inhibit 1,1-diphenyl-2-picrylhydrazyl (DPPH). Total proanthocyanidins for both water and methanol extracts were 20.2 ± 0.01 and 30.6 ± 0.51 mg g−1 (catechin equivalent) while the total phenol contents were 20.0 ± 0.52 and 35.6 ± 1.42 mg mL−1 (tannic acid equivalent), respectively. Positive correlations R 2 = 0.85, R 2 = 0.94, R 2 = 0.97 for DPPH, reducing power and 2′-azino-bis(3-ethylbenzo thiazoline)6-sulphonic acid (ABTS). Linear regression analysis also produced a high correlation coefficient with total proanthocyanidins (DPPH, R 2 = 0.69; ABTS, R 2 = 0.94). H. acida extracts showed low antibacterial activity (minimum inhibitory concentration (MIC) value ≥5.0 mg mL−1) against gram negative bacteria but significantly (MIC value ≤2.5 mg mL−1) inhibited the growth of the gram positive strains tested. Qualitative TLC of the extract was positive for flavonoids, phenols, steroids and triterpenoids. The results of this study support the use of H. acida in traditional Nigerian medicine and show that the alcoholic extract of the leaves can be used as an easily accessible source of natural antioxidant and can be of assistance in some dermatological problems.

Urinary 1H-NMR Metabonomics Study on Intervention Effects of Soya Milk in Africans

Metabonomics is an important tool in understanding the toxicological or therapeutic effects of interventions by analysing metabolic profiles and interpreting complex multi‐dimensional spectroscopic/spectrometric data using multivariate data analysis. The objectives of this study were to evaluate the metabolic changes following a short‐term 5 day soya milk intervention, and to investigate factors that influence soy‐phytoestrogen metabolism focused on Africans based in either UK or Nigeria. 1H‐NMR metabonomics was applied to analyse urine samples collected at four phases I–IV (pre, days 3 and 5, and post) of the soy‐intervention from African volunteers (n = 40 in total). Individual proton NMR spectra were visually and statistically assessed using multivariate analyses (MVA): principal component analysis (PCA) and (orthogonal‐) partial‐least square–discriminant analysis ((O‐) PLS‐DA). In addition, 22 endogenous metabolites were quantified using a Chenomx NMR suite. The results showed the levels of analysed endogenous metabolites (creatinine adjusted) present ranged from 4 µ m to 12 m m with large inter‐subject variances in acetate, acetone, lactate and trimethylamine. The MVA results showed high inter‐individuality and sampling variances based on PCA score plots, and demonstrated soy metabolism to be significantly influenced by location and gender by both PLS‐DA and O‐PLS‐DA. Copyright

Effect of Flabellaria paniculata Cav. extracts on gastric ulcer in rats

BackgroundThe leaves and root of Flabellaria paniculata (Malpighiaceae) are frequently used in the treatment of wounds and ulcers in Nigerian folk medicine. The purpose of this study was to compare the effect of ethanolic extracts from the leaves (FPL) and root (FPR) of F. paniculata on gastric ulcers in rats.MethodsThe effect of FPL and FPR (100, 200 and 400 mg/kg) was evaluated in ethanol and indomethacin gastric ulcer models. Control groups for FPL and FPR were orally treated with 3% Tween 20 and distilled water respectively. FPL was further investigated in pylorus ligation model. Misoprostol and cimetidine were used as reference.ResultsFPL significantly (P < 0.05) reduced gastric lesions by 82.22% and 67.32% in ethanol and indomethacin induced ulcer models at 100 mg/kg respectively while FPR (100, 200 and 400 mg/kg) did not exert significant effect in the two models. In pylorus ligation model, FPL exerted a significant preventive antiulcer effect as indicated by reduction in gastric volume at 200 and 400 mg/kg doses. Only 400 mg/kg of the extract exerted a significant reduction in ulcer index when compared with the control group. The oral route LD50 of FPL was estimated to be 4570 mg/kg while that of FPR was 2754 mg/kg. The LD50 in intraperitoneal injection was estimated to be 1202.26 and 1380.38 mg/kg for FPL and FPR respectively. The phytochemical investigation showed that both extracts possess triterpenoids and saponin, while the presence of flavonoid was detected only in FPL.ConclusionsThe results of this study indicated that FPL and not FPR is effective against experimentally induced gastric ulcers. The presence of varied phytochemical constituents probably influenced the pharmacological differences between the two extracts.

Chemical and biological studies on Bridelia ferruginea grown in Nigeria

Abstract Phytochemical investigation of the methanolic extract of dried leaves of Bridelia ferruginea led to the isolation and identification of fourteen compounds (1–14): compound 1 [mixture of palmitic, stearic and oleic acids], stearyl monoester of 2-O-β-ᴅ-glucosylglycerol (2), 6β-hydroxy-(20R)-24-ethylcholest-4-en-3-one (3a), 6β-hydroxy-(20R)-24-ethylcholest-4,22-dien-3-one (3b), lutein (4), vomifoliol (5), corilagin (6), kaempferide-3-O-β-ᴅ-glucoside (7), myricetin (8), isomericitrin (9), isoquercetin (10), myricitrin (11), quercitrin (12), rutin (13), and β-sitosterol glucoside (14). The total extract exhibited moderate activity towards CB2 receptor and 90% inhibition against leishmanial pathogen Trypanosoma brucei. Compound 4 exhibited 73% displacement in CB2 receptor with IC50 56.47 μM, and 93% inhibition towards T. brucei with IC50 4.16 μM. Compound 11 showed 99% inhibition towards Escherichia coli with IC50 1.123 μM.

Evaluation of Baylis–Hillman Routes to 3-(Aminomethyl)coumarin Derivatives

Abstract The relative merits of two different Baylis–Hillman approaches toward the preparation of coumarin derivatives, containing peptide-like side chains, have been explored. In one approach, use of methyl acrylate as the activated alkene requires a protecting group strategy, an approach that is not necessary when using tert-butyl acrylate. [Supplementary materials are available for this article. Go to the publishers online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] GRAPHICAL ABSTRACT

Phytochemical study of Piliostigma thonningii, a medicinal plant grown in Nigeria

Piliostigma thonningii (Schumach.) Milne-Redhead. (Leguminosae) is used for various medicinal purposes in African countries. Phytochemical investigation of P. thonningii yielded two compounds newly isolated from natural sources, 2β-methoxyclovan-9α-ol (1), and methyl-ent-3β-hydroxylabd-8(17)-en-15-oate (2), along with 14 known compounds (3–16). Compounds 1 and 4 (alepterolic acid) showed potential selectivity towards Trypanosoma brucei brucei with IC50 7.89 and 3.42 μM, respectively. Compound 2 showed activity towards T. brucei and Leishmania donovani Amastigote with IC50 3.84 and 7.82 μM, respectively. The structure activity relationship (SAR) of the isolated metabolites suggested that hydroxylation at C-2 enhances the antiprotozoal activity towards T. brucei in sesquiterpenes 1 and 3. Similarly hydroxylation at C-3 in labdane diterpenes elevates the antiprotozoal activity towards T. brucei.

N-(arylsulphonyl)tetrahydropyridinium salts: intermediates for multi-ring heterocycles. Part 1. Synthesis of hexahydropyrido[1,2-b][1,2,4]benzothiadiazine dioxides

N-(Arylsulphonyl)tetrahydropyridinium salts were obtained regiospecifically and in high yield by smooth triflate-assisted decarbonylation of the corresponding N-(arylsulphonyl)piperidine-2-carboxylic acid chlorides at room temperature. These synthons were converted into the nitroamines, which reductively cyclocondensed to give the new 9-substituted tricyclic azacycles, hexahydropyrido[1,2-b][1,2,4]benzothiadiazine 6,6-dioxides.

Sulphur-based directed benzylic metallations: lithiations of alkylarenesulphonates

Benzylic anions (6) are obtained by regio-specific lithiations of ethyl 2-methylbenzenesulphonates. Evidence for the presence of the ethyl 2-lithiomethylbenzenesulphonates was obtained by efficient quenching studies with a range of electrophiles. Lithiations of the 2,4-dimethyl compound (9) gave the 2-lithiomethyl anion only, indicative of a predominant co-ordination mechanism in the lithiations.