Study on anti-diabetic activities of crude methanolic extracts of Loranthus micranthus (Linn.) sourced from five different host trees.

The hypoglycaemic and anti-hyperglycemic activities of dried leaves of Loranthus micranthus (Linn.) (Loranthaceae), parasitic on Persea americana, Baphia nitda, Kola acuminata, Pentaclethra macrophylla, Azadirchta indica, were evaluated in normoglycemic and alloxan-induced diabetic albino rats. Normoglycemic and alloxan-induced diabetic rats were treated (intraperitoneally) with 200 mg/kg of the respective methanolic extracts of Loranthus micranthus (Linn.), glibenclamide (positive control), and 20% (v/v) Tween 20 solution (negative control). The sugar levels of the withdrawn blood samples were determined by o-toluidine spectrophotometric method. The studies indicate that the crude methanolic extract of Loranthus micranthus (Linn.) exhibited statistically significant hypoglycaemic (P < 0.001) and anti-hyperglycemic (P < 0.001) activities in normoglycemic and alloxan-induced diabetic albino rats, respectively. The hypoglycaemic effect was found to be dose-dependent. The maximum effect of the mistletoe extract (400 mg/kg) from Persea americana on alloxan-induced diabetic rats was found to be statistically comparable with that of the positive control, glibenclamide, at 24 h after administration, with a percentage reduction of blood sugar levels of 82.59 and 83.34%, respectively. Acute toxicity tests of the methanolic extracts of Persea americana, Baphia nitda, Kola acuminata, Pentaclethra macrophylla, Azadirchta indica host trees in mice gave LD(50) values of 11650, 11650, 5900, 5900 and 5900 mg/kg, respectively, which are all within the practically non-toxic range. The methanolic extract of African mistletoe was found to be a good candidate for alternative and/or complimentary medicine in the management of diabetes mellitus. The leaves of the Eastern Nigerian species of the African mistletoe harvested from Kola acuminata, Azadirchta indica and Baphia nitda host trees exhibited comparatively better anti-hyperglycemic activities among the host trees studied.

Better biosynthesis of ergot alkaloids.

Different culture media containing different effectors for production of ergot-alkaloids were prepared. The culture media were inoculated with equal mycelia of Claviceps purpurea and some were incubated for 22 days and some incubated for 45 days. The medium that contained a mixture of glucose, glycine and tryptophan showed highest yield of the alkaloids and reached the maximum period for production of agroclavine faster.

Spectrophotometric determination of nikethamide by charge--transfer complexation with chloranilic acid.

A Spectrophotometric method is described for assay of nikethamide which was based on charge transfer complexation between it and chloranilic acid. They form a complex with stoichiometric ratio of 1:1 and showed l-max at 535 nm. Maximum complexation occurred 30 min after mixing the reactants and was stable for 12 hr. The molar absorptivity, association constant and free energy for the complex were 1.05 x 1.0(2), 4.40 x 10(-2) litre mole-1 and 1819.02 kcal respectively. Conformity to Beer's Law was within the concentration range of 1-2.5 x 10(-4), which enabled the assay of dosage forms of the drug at microquantities.

Antimicrobial activities of some amino derivatives of 5, 7-dibromo-2-methyl-8-benzoyloxyquinoline.

In an attempt to design and synthesize more potent quinoline-based chemotherapeutic agents structural modifications of 5, 7-Dibromo-2-methyl-8-benzoyloxyqinoline was carried out. The replacement of the bromine atoms with the requisite alkylamino compound gave four amino-derivatives viz: bis(dipropylamino)-dipyrrolidino-, dipiperidino- and dipiperazino derivatives. The antimicrobial activities of these compounds were investigated against selected Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Escherichin coli, Pseudomonas aeruginosa and Klebsiella spp) and yeast (Candida albicans). All the compounds showed broad or significant antimicrobial activity, which varied from two to ninety times that of the parent compound. The dipyrrolidino derivative was the most effective against Gram-positive bacteria and yeast while the dipiperidino derivative was the most effective against Gram-negative bacteria. No correlation has been established between the minimum inhibitory, (MIC) concentrations of the derivatives and the structural modifications.

Detection of alpha-methyldopa on thin-layer plates using pi-acceptors in 1,4-dioxane.

pi-Acceptors (P-chloranil and chloranilic acid) in 1,4-dioxane were used to detect alpha-methyldopa on thin layer plates. Thin layer plates coated to a thickness of 0.25 mm with silica gel G60 were spotted with solution of alpha-methyldopa from drug formulations and pure alpha-methyldopa solution. The plates were developed in a solvent system of methanol: glacial acetic acid: water (14:5:3). The developed plates were dried and sprayed with pi-acceptors, and further were counter-sprayed with dimethylformamide (DMF). P-Chloranil gave an immediate blue green complex with alpha-methyldopa which intensified on counter-sprayed with DMF. alpha-methyldopa (reference sample and those from drug formulations) gave Rf of 0.85 and excipients from the drug formulations did not interfere with the result.

Kinetics of Autoxidation of an Oil Extract from Terminalia catappa.

Soxhlet extractor was used in the extraction of oil from milled seeds of Terminalia catappa using petroleum ether (40-60 degrees ). The optimal oil yield was 56.71+/-1.66% with a viscosity of 40.79+/-1.05 centipoises. Other parameters of the oil were found as follows; specific gravity-0.9248, refractive index-1.4646, acid value-3.35, peroxide value-8.6, saponification value-166.2, and unsaponifiable matter-1.46. The crude oil extract was water-degummed, bleached and deodorized to generate what we called refined oil. Autoxidation of the crude and refined T. catappa oil extract was done at five different temperatures of 0+/-0.1 degrees , 20+/-0.1 degrees , 40+/-0.1 degrees , 60+/-0.1 degrees and 80+/-0.1 degrees and also in the presence of pure alpha-tocopherol at a concentration of 1.0% (w/v) by measuring peroxide value variations over 96 h. In all evaluations, the refined oil exhibited lower tendency towards autoxidation but not at temperatures above 60+/-0.1 degrees . The use of Arrhenius equation revealed generally very low activation energies of 0.0261 cal/degxmol and 0.0122cal/degxmol for crude oil and antioxidant-treated crude oil, respectively and 0.0690 cal/degxmol and 0.0177 cal/degxmol for the refined oil. This study indicates T. catappa seed oil to be potential pharmaceutical oil with excellent characteristics.

Antimicrobial activities of some amino derivatives of 5,7-dibromo-2-methyl-8-hydroxyquinoline.

The bromine atoms of the title compound, 5,7-dibromo-2-methyl-8-hydroxyquinoline were replaced by the requisite amino compound to afford 6 amino derivatives viz: bis(diethylamino)-, bis(dibutylamino)-, bis(dicyclohexylamino)-, dipyrolidino-, dipiperidino- and dipiperazino derivatives. The antimicrobial activity of these compounds were investigated against selected gram positive (Staphylococcus aureus and Bacillus subtilis), gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and yeast (Candida albicans). All the compounds showed significant activity against the test microorganisms, from 5-30 times compared to the title compound. It was observed that all derivatives were more effective against gram positive bacteria. No correlation has been established between the minimum inhibitory (MIC) concentrations of the derivatives and the structural modifications.