Flavonoid glycosides from callus cultures of Dysosma versipellis / 中国中药杂志

Various chromatographic techniques, including silica gel column chromatography, Sephadex LH-20, preparative thin-layer chromatography, and preparative HPLC, were employed to isolate the chemical constituents from callus cultures of Dysosma versipellis. Structures of the compounds were elucidated based on UV, IR, MS and NMR spectroscopic data analysis. Totally, seven flavonoid glycosides were isolated from the 95% ethanol extract of the callus cultures and identified as kaempferol-3-O-[6″-(3″'-methoxy)-malonyl]-β-D-glucopyranoside(1), kaempferol-3-O-(6″-O-acetyl)-β-D-glucopyranoside(2), kaempferide-3-O-β-D-glucopyranoside(3), kaempferol-3-O-β-D-glucopyranoside(4), isoquercitrin(5), quercetin-4'-O-β-D-glucopyranoside(6) and kaempferol-3-(6″-malonyl)-β-D-glucopyranoside(7), respectively.All these compounds were isolated from callus cultures of D. versipellis for the first time.Compounds 1, 2, 3, 6 and 7 were firstly obtained from plant materials of D. versipellis, and compound 1 was a new compound.

Antimicrobial activity of Anonna mucosa (Jacq.) grown in vivo and obtained by in vitroculture

Brazilian flora includes numerous species of medicinal importance that can be used to develop new drugs. Plant tissue culture offers strategies for conservation and use of these species allowing continuous production of plants and bioactive substances. Annona mucosa has produced substances such as acetogenins and alkaloids that exhibit antimicrobial activities. The widespread use of antibiotics has led to an increase in multidrug-resistant bacteria, which represents a serious risk of infection. In view of this problem, the aim of this work was to evaluate the antibacterial potential of extracts of A. mucosa obtained by in vitro techniques and also cultured under in vivo conditions. Segments from seedlings were inoculated onto different culture media containing the auxin picloram and the cytokinin kinetin at different concentrations. The calluses obtained were used to produce cell suspension cultures. The materials were subjected to methanol extraction and subsequent fractionation in hexane and dichloromethane. The antimicrobial activity against 20 strains of clinical relevance was evaluated by the macrodilution method at minimum inhibitory and minimum bactericidal concentrations. The extracts showed selective antimicrobial activity, inhibiting the growth of Streptococcus pyogenes and Bacillus thuringiensis at different concentrations. The plant tissue culture methods produced plant materials with antibacterial properties, as well as in vivo grown plants. The antibacterial activity of material obtained through biotechnological procedures of A. mucosa is reported here for the first time.

Quercetin in Callus Cultures of Clitoria ternatea linn.

Callus cultures of leaf, root and hypocotyledon of Clitoria ternatea were developed independently in MS medium supplemented with 1 mgl-1 each of 2,4-Dichlorophenoxy acetic acid (2,4-D), benzyl adenine (BA), Indole-3-acetic acid (IAA), and Kinetin. Three months old calli were subjected to phytochemical screening which showed the presence of alkaloids, amino acids, flavonoids, carbohydrates, phenolic compounds, tannins, saponins, mucilage and proteins. Quercetin, a flavonoid having pharmacological functions was quantitatively estimated by Reversed - Phase HPLC in natural leaf and callus cultures of leaf, hypocotyledon and root. Leaf callus was found to content the highest amount of Quercetin, i.e. 1.21% w/v as compared to other callus while natural leaf extract showed 1.25%w/v of Quercetin.

Larvicidal activity of Artemisia annua L. callus culture against Anopheles stephensi larvae.

The emergence of resistance by both Plasmodium falciparum and Anopheles stephensi made the search for an alternative environmentally safe plant based insecticide inevitable. Artemisia annua is a well known antimalarial. Present study is an attempt to induce callus production from young leaves of Artemisia annua plant and study its larvicidal activity against larvae of Anopheles stephensi. Callus was initiated by using different concentrations of auxins and cytokinins. A suitable culture media was standardized for optimal growth of callus. Healthy callus cultures were obtained in the slightly modified Murashige and Skoog’s medium + NAA and BAP (0.03 and 0.2 mg l-1 respectively) + Sucrose 20 gm l-1 + Agar 8 gm l-1 within 28 days of inoculation. Callus was successively extracted in order of increasing polarity of solvents. Larvicidal activity, in terms of lethal concentration (LC50) of the callus extract in chloroform was calculated to be 18.45 ± 0.75 ppm after 72 hr against third instar larvae of A. stephensi.

Relation between electrokinetic potentials and growth in callus cultures of Trigonella foenum-graecum.

Callus cultures of Trigonella foenum-graecum were initiated from radicle or cotyledon portions of seedlings and young leaves and maintained on modified 1-B5 medium. The callus mass was disaggregated by mechanical agitation and the discrete cells thus obtained were used to measure their electrokinetic potential. Studies pertaining to the effects of ageing on electrokinetic potential and growth index revealed a relationship between these two parameters. Thus, the rate of change of electrokinotie potential with age could be employed as a parameter to study the growth kinetics of cells in callus cultures.