Different wavelengths light to induce physiological changes callus for the biosynthesis of gymnemic acid in Gymnema sylvestre

A callus culture of Gymnema sylvestre was cultivated under different light conditions (blue, white, red and green light). Green-white coloured gymnemic acid containing cell groups were formed on the surface of the callus culture under blue light respectively. The phytohormone kinetin enhanced the gymnemic acid formation in blue light, but was unable to induce gymnemic acid in darkness. The phytohormone 2,4-D induced the formation gymnemic acid under all light conditions studied. Analysis of the callus growth phase under all treatments revealed that gymnemic acid accumulation was maximum (12.22 mg/g d.w) in the callus during stationary phase of 45 days, grown in MS medium with 2,4-D (1.5 mg/l) and KN 0.5 mg/l under white fluorescent light. Blue light enhanced the gymnemic acid accumulation up to 4.4 fold of that found under white fluorescent light and 2.8 fold of that found in intact leaves. Present findings concluded that blue light can be used as tool for enhancing pentacyclic tri-terpenoids in batch culture of G. sylvestre

Condiciones optimizadas para inducción de callos, regeneración de plantas y acumulación de alcaloides en explantes de tallos y brotes de Phyla nodiflora

The present study describes callus induction and the subsequent plant regeneration with alkaloids accumulation instem and shoot tip explants of Phyla nodiflora. Both explants were cultured on different media (MS, B5, SH and WPM) for callus induction. Stem explants showed better callus biomass (dry weight) than shoot tip explants with green compact callus when cultured on MS medium containing 1.5 mg L–1 α-naphthalene acetic acid. Shoots were regenerated from the callus on MS medium with 1.5 mg L–1 α-naphthalene acetic acid and 1.0 mg L–1 benzyl adenine. The rooting of all regenerated shoots was successfully performed on half-strength MS medium with 1.0 mg L–1 indole-3-butyric acid. The plantlets were acclimatized and established in soil (90%) and exhibited morphological characteristics similar to those of the mother plant. In addition, the alkaloids content was higher in regenerated callus than intact stem and shoot tip explants, which were analyzed by a gravimetric method, TLC (thin layer chromatography) and HPTLC (high performance thin layer chromatography). The proposed method could effectively be applied for the conservation and clonal propagation to meet the pharmaceutical demands of this medicinally important speciesEl presente estudio describe la inducción de callos y la posterior regeneración de plantas con la acumulación de alcaloides en los explantes de tallos y brotes de Phyla nodiflora. Para la inducción de callos, ambos explantes fueron cultivados en diferentes medios (MS, B5, SH y WPM). Los explantes de tallos tuvieron mejor biomasa (peso seco) de callo que explantes de ápices de naturaleza verde compacta cuando se cultivaron en un medio MS con 1,5 mg L–1de ácido α-naftalén acético. Los brotes fueron regenerados a partir de los callos en medio MS con 1,5 mg L–1 de ácido α-naftalén acético y 1,0 mg L–1 de benciladenina. El enraizamiento de todos los brotes regenerados se realizó con éxito en un medio ½ MS con 1,0 mg L–1 de ácido indol-3-butírico. Las plántulas fueron aclimatadas y establecidas en suelo (en un 90%) y mostraron características morfológicas similares a las de la planta madre. Además, el contenido de alcaloides fue mayor en los callos regenerados que en los explantes de tallo y brotes intactos, que fueron analizados por un método gravimétrico, TLC y HPTLC. El método propuesto se podría aplicar con eficacia para la conservación y propagación clonal, a fin de satisfacer la demanda farmacéutica de esta especie medicinalmente important

HPTLC/HPLC and gravimetric methodology for the identification and quantification of gymnemic acid from gymnema sylvestre methanolic extracts

Gymnemic acid (GA), a well known anti-diabetic compound has been detected in methanol extracts of intact leaves and in vitro callus cultures derived from leaf explants of Gymnema sylvestre. Callus biomass was developed in MS medium with optimum plant growth regulators (OPGRs) of 2,4-D (1.5 mg L-1) + KN (0.5 mg L-1) under abiotic stress conditions at 45 days determined by growth curve analysis. GA detection and quantification were carried out using thin-layer chromatography (TLC), high-performance thin-layer chromatography (HPTLC), high-performance liquid chromatography (HPLC), and gravimetric techniques. GA detection peak area and their absorption spectra were evaluated through HPTLC and HPLC with the standard GA. Quantification of GA had showed the linearity, accuracy, robustness and precision by HPLC. GA content was significantly higher in gravimetric method than HPLC. All these methods were found to be simple, accurate, selective and rapid and could be successfully applied for the determination of GA. It could have potential as a pharmaceutical drug for Type 1 diabetes mellitus (IDDM) and obesity

Preparation, properties and biological applications of water soluble chitin oligosaccharides from marine organisms

Chitin oligosaccharides (COSs) can be isolated from various natural resources, which have widely been used in biological active supplements (BAS) for the benefit of humankind. Several technological approaches for the preparation of COSs such as enzymatic, chemical, acid-catalysts hydrolysis, microwave radiation, membrane bioreactor methods have been developed and among them, membrane bioreactor, bioconversion and continuous mass production technologies are reported to be excellent. Compounds isolated from natural products have made a drastic impact on the pharmaceutical industry and especially, water-soluble chitin oligosaccharides have shown greater clinical activity, which have been demonstrated in various cell lines of disease significance. The activities of these COSs were being investigated in different patients, animals and even plants as a broad phase clinical trial program. In the present article, we have discussed the COSs preparation by different methods through comprehensive diffraction procedures along with the merits and demerits given in detail. In addition, a summary of recent work describing the synthesis and biological activities of water-soluble COSs has been presented here

Isolation of MERS Coronavirus from a Dromedary Camel, Qatar, 2014

We obtained the full genome of Middle East respiratory syndrome coronavirus (MERS-CoV) from a camel in Qatar. This virus is highly similar to the human England/Qatar 1 virus isolated in 2012. The MERS-CoV from the camel efficiently replicated in human cells, providing further evidence for the zoonotic potential of MERS-CoV from camels