Kuepferia kanchii sp. nov. (Gentianaceae) from Sikkim Himalaya

Kuepferia kanchii D. Maity, Sentu K. Dey & Adr. Favre, a new species from Sikkim Himalaya, is described and illustrated. It differs from its close relative K. infelix (C. B. Clarke) Adr. Favre ( = Gentiana infelix C. B. Clarke) by having sessile and smaller flowers, and smaller floral parts. Kuepferia kanchii is further characterized by a white corolla with bluish green patches on the outside at the base of each corolla lobe, and a corolla tube flushed with light green inside towards the base, blue filaments, sessile stigma, smaller capsule, and trigonous–elongated, ca 0.8 mm long and curved seeds.     

Antioxidant and cytotoxic activity of bioactive phenolic metabolites isolated from the yeast-extract treated cell culture of apple

Buds of in vitro-grown shoots of two purple-fleshed potato genotypes were successfully cryopreserved by encapsulation-vitrification (Encap-vitri) and droplet-vitrification (Drop-vitri). Optimal time durations of exposure to PVS2 for shoot regrowth of cryopreserved buds were 5–7 h and 6 h for ‘E03-2677’ and for ‘Blue Congo’, respectively, in Encap-vitri, and 30–50 min and 40 min for the former and the latter, respectively, in Drop-vitri. Higher rates of shoot regrowth were obtained in 1.5–2.0 mm-buds than in 1.0–1.4 mm-ones in Encap-vitri for ‘E03-2677’ and ‘Blue Congo’, while opposite results were found in Drop-vitri. In ‘Blue Congo’, only apical shoot tips survived and developed into shoots, with one shoot produced in one cryopreserved bud in Encap-vitri and Drop-vitri. In ‘E03-2677’, survival and shoot regrowth patterns were similar to those of ‘Blue Congo’ in Encap-vitri. However, both apical and axillary shoot tips survived and developed into two shoots in one bud in Drop-vitri. In ‘E03-2677’, histological observations revealed only apical shoot tips survived following Encap-vitri, while both apical and axillary shoot tips survived following Drop-vitri. Vegetative growth in shoots regenerated from Encap-vitri and Drop-vitri after 3 weeks of post-thaw culture was significantly lower than that from control, but markedly increased after 6 months of post-thaw culture. In both ‘E03-2677’ and ‘Blue Congo’, number of microtubers per shoot, per vessel and ≥3 mm in diameter were significantly greater in shoots regenerated from Encap-vitri than in those from the control. Assessments by ISSR and RAPD of genetic stability did not find any polymorphic bands in regenerants recovered from Encap-vitri and Drop-vitri. To the best of our knowledge, this is the first report on cryopreservation of purple-fleshed potato by vitrification-based procedures. Results reported here would provide valuable basic and technical information on cryopreservation of purple-fleshed potato.     

Maximizing power generation from dark fermentation effluents in microbial fuel cell by selective enrichment of exoelectrogens and optimization of anodic operational parameters

Objective

To selectively enrich an electrogenic mixed consortium capable of utilizing dark fermentative effluents as substrates in microbial fuel cells and to further enhance the power outputs by optimization of influential anodic operational parameters.

Results

A maximum power density of 1.4 W/m³ was obtained by an enriched mixed electrogenic consortium in microbial fuel cells using acetate as substrate. This was further increased to 5.43 W/m³ by optimization of influential anodic parameters. By utilizing dark fermentative effluents as substrates, the maximum power densities ranged from 5.2 to 6.2 W/m³ with an average COD removal efficiency of 75% and a columbic efficiency of 10.6%.

Conclusion

A simple strategy is provided for selective enrichment of electrogenic bacteria that can be used in microbial fuel cells for generating power from various dark fermentative effluents.

     

Electrozymographic evaluation of the attenuation of arsenic induced degradation of hepatic SOD,catalase in an in vitro assay system by pectic polysaccharides of Momordica charantia in combination with curcumin

Momordica charantia (MC) fruit known as bitter gourd, is of potential nutritional and medicinal value. The objectives of the present in vitro study were to evaluate the efficacy of bioactive pectic polysaccharides (CCPS) of MC along with another well-known bioactive compound curcumin in the abrogation of hepatocellular oxidative stress persuaded by sodium arsenite. Electrozymographic method was developed for the assessment of superoxide dismutase (SOD) and catalase activities of liver tissues maintained under an in vitro system. A significant association of CCPS of MC in combination with curcumin was found in the alleviation of oxidative stress induced by sodium arsenite in liver slice. Generated data pointed out that CCPS of MC and curcumin separately or in combination can offer significant protection against alterations in malondialdehyde (MDA), conjugated diene (CD) and antioxidative defense (SOD, CAT) markers. Furthermore, results of hepatic cell DNA degradation strongly supported that both these co-administrations have efficacy in preventing cellular damage. This is the first information of extracted polysaccharides from MC preventing arsenic induced damage in a liver slice of rat.     

The role of plant growth regulators on direct and indirect plant regeneration from various organs of <Emphasis Type="Italic">Leucaena leucocephala</Emphasis>

Prolific differentiation of shoot buds of Leucaena leucocephala was induced from the different plant parts viz. cotyledon, hypocotyl and leaf. Adventitious shoot bud formation was recorded with prudent application of N⁶-2- (isopentenyl) adenosine and 15% (v/v) coconut water. Coconut water alone was unable to produce any beneficial effect with regard to the shoot bud proliferation but the response was augmented with the increase in concentration of N⁶-2- (isopentenyl) adenosine. However supra-optimal level of N⁶-2-(isopentenyl) adenosine was inhibitory. Best response was recorded from the cotyledon explant at 2 mg dm⁻³ N⁶-2-(isopentenyl) adenosine compared to the other two explants. Comparative assessment was undertaken following the same experimental protocol in liquid shake culture. The regenerated shoot buds were subcultured in plant growth regulator-free medium where leafy shoot emergence was recorded. Optimum regeneration of roots was observed in these shoots in presence of 1 mg dm⁻³ α-naphthalene acetic acid. Plantlets were finally hardened following standard procedures before transplantation to the field. In another experimental set up, the de-embryonated cotyledons regenerated shoot buds via callus formation. The regenerated shoots and plantlets obtained through callus mediated organogenesis could be used for rapid multiplication and also for the genetic improvement of individual clones of Leucaena leucocephala.     

Malarial infection develops mitochondrial pathology and mitochondrial oxidative stress to promote hepatocyte apoptosis

Activation of the mitochondrial apoptosis pathway by oxidative stress has been implicated in hepatocyte apoptosis during malaria. Because mitochondria are the source and target of reactive oxygen species (ROS), we have investigated whether hepatocyte apoptosis is linked to mitochondrial pathology and mitochondrial ROS generation during malaria. Malarial infection induces mitochondrial pathology by inhibiting mitochondrial respiration, dehydrogenases, and transmembrane potential and damaging the ultrastructure as evident from transmission electron microscopic studies. Mitochondrial GSH depletion and formation of protein carbonyl indicate that mitochondrial pathology is associated with mitochondrial oxidative stress. Fluorescence imaging of hepatocytes documents intramitochondrial superoxide anion (O₂^?) generation during malaria. O₂^? inactivates mitochondrial aconitase to release iron from iron–sulfur clusters, which forms the hydroxyl radical (OH) interacting with H₂O₂ produced concurrently. Malarial infection inactivates mitochondrial aconitase, and carbonylation of aconitase is evident from Western immunoblotting. The release of iron has been documented by fluorescence imaging of hepatocytes using Phen Green SK, and mitochondrial OH generation has been confirmed. During malaria, the depletion of cardiolipin and formation of the mitochondrial permeability transition pore favor cytochrome c release to activate caspase-9. Interestingly, mitochondrial OH generation correlates with the activation of both caspase-9 and caspase-3 with the progress of malarial infection, indicating the critical role of OH.     

Efficient synthesis of 3,3-diheteroaromatic oxindole analogues and their in vitro evaluation for spermicidal potential

Syntheses of 3,3-diheteroaromatic oxindole derivatives has been achieved by coupling indole-2,3-dione (isatin) with differently substituted indoles and pyrrole in presence of I₂ in i-PrOH. The in vitro spermicidal potentials and the mode of spermicidal action of the synthesized analogues were evaluated and the derivative, 3,3-bis (5-methoxy-1H-indol-3-yl) indolin-2-one (3d) exhibited most significant activity.     

Click chemistry based rapid one-pot synthesis and evaluation for protease inhibition of new tetracyclic triazole fused benzodiazepine derivatives

We describe herein a one-pot synthesis of novel tetracyclic scaffolds that incorporate a fusion of a proline, 1,2,3-triazole ring with [1,4]-benzodiazepin-8(4H)-one ring systems following click chemistry. The expected peptide bond formation followed by in situ 1,3-dipolar cycloaddition in absence of any catalyst led to the formation of new triazole fused benzodiazepine derivatives.