Development of chromatographic profiles by HPTLC and characterization of phenolics in the leaf extracts of Tectona grandis

Vastrad Jyoti V. and Goudar Giridhar

Tectona grandis, known as teak is a forest species which belongs to the family Verbenaceae. It occurs in deciduous forests of all tropical and sub-tropical regions. An attempt is made to characterize the phenolic compounds in teak leaf that decide its utility either as natural dye or as eco-friendly antimicrobial finish. Extraction of phenolic compounds is carried out with absolute ethanol, 50% ethanol and distilled water as solvents. Qualitative screening of phytochemicals in solvent extracts revealed the presence of alkaloids, flavonoids, tannins, saponins and terpenpoids determined by various chemical tests. Total phenolic content (TPC) analyzed by folin-ciocalteu reagent assay method (λmax765) and total flavonoid content (TFC) analyzed by colorimetric method (λmax415) was high in 50% ethanol solvent i.e. 52.50 & 124.12mg/g respectively compared to other two solvents. Chromatographic analysis by High Performance Thin Layer Chromatography (HPTLC) was carried out to evaluate the phenolic compounds in various leaf extracts of T. grandis and the densitometry was optimized by scanning the developed profiles at 270, 320 and 370nm.

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Biochemical adaptations of Ocimum sanctum to NaCl stress

Bajpai Shukla Monika, Gupta Neha and Majumdar Singh Rita

Ocimum sanctum is a pharmaceutically important medicinal plant. The present study was carried out with an aim to analyse the potential candidature of Ocimum sanctum for a possible halophyte. The experimental plant was subjected to different concentrations (0, 20, 40, 60, 80μM) of sodium chloride. A popular pollutant of saline stressed soils and antioxidant defense along with the oxidative stress generated was studied in the leaves of Ocimum sanctum L. An increased level of superoxide anion radical (O2 2- ) and H2O2 evidenced oxidative stress conditions in leaves. To scavenge the ROS, the enzymatic antioxidative defense displayed promising results showing an increase in the conc. of SOD, Cat, APX and GR. The accumulation of Na+ was analysed using Inductively Coupled Plasma Mass Spectroscopy.

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Effect of mild thermal treatment and pH in quality of minimally processed marsilea vestita leaves

Gopal Richa, Keshav Amit, Soni A.B. and Sinha Bharti

Color is an important sensory characteristic to determine the acceptability of a product. Kinetics of thermal degradation of chlorophyll a (Cha) and chlorophyll b (Chb) in Marselia Vestita Leaves was studied at pH values of 5.6 and 6.6 and temperatures of 343 to 363 K. The degradation has been found to be of first order and is higher at lower pH and higher temperature. Rate constant decreases for Cha and Chb as pH was lowered from 6.6 to 5.6 at T = 343K. For the fixed pH of 6.6, it was found that as the temperature was raised from 343 K to 363 K, the rate constant value increases from 0.0249 to 0.0322 and 0.0228 to 0.028 for Cha and Chb. The activation energies of Cha and Chb were found to be 15.88 kJ/mol and 10.68 kJ/mol at pH = 6.6 and 17.5 kJ/mol and 13.35 kJ/mol at pH 5.6. The activation energy of chlorophyll a was found to be higher than chlorophyll b, signifying that chlorophyll a is more heat sensitive than chlorophyll b. Thus the study reveals that thermal preservation should be performed at higher pH and lower temperature in order to have minimum degradation of chlorophyll.

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The impacts of light quality and intensity on N2O, CO2 and CH4 emissions of the rice phyllosphere and roots at tillering stage in a liquid culture medium system

Liu Jiani, Chen Zebin, Yu Lei, Li Bing, Lin Li, Chen Wurong and Xu Shengguang

N2O, CO2, and CH4 are important greenhouse gases (GHGs) in paddy fields and rice plants play an important role in GHG emissions in paddy fields. However, the source of GHG emissions from rice phyllosphere and roots and its relationship to light quality and intensity are still not clear. In this study, a simultaneous leaf-root determination was designed to explore the impact of illumination on GHG emissions of rice phyllosphere and roots at tillering stage in a liquid culture medium system. The results showed the following. (a) Under natural sunlight (Nitrogen source: NH4NO3-N, 90 mg/L), the mean rate of N2O emission from rice phyllosphere was 35.66 μg pot-1 h-1, accounting for 40% of the total N2O-N evaporation loss for the whole rice plant. (b) Under the same conditions, the CO2 emission rates from the rice phyllosphere and roots in the daytime and night were -13.58, 8.28 mg pot-1 h-1 and 28.13, 8.39 mg pot-1 h-1 respectively. However, no CH4 net emission effects were observed in the rice phyllosphere or roots at same time (P>0.05). (c) Under a constant weak LED light (1600 Lux), N2O and CO2 emissions of rice phyllosphere can be inhabited by red and blue lights significantly compared with yellow and green lights but N2O emission of rice roots can be promoted by red and blue light synchronously under the same condition (P>0.05). (d) Within the range of 0-6000 Lux, light intensity enhancements can reduce CO2 emission of rice phyllosphere but it will synchronize promote N2O emissions from rice phyllosphere and roots. In contrast, natural sunlight can enhance N2O emissions of the whole rice plant significantly and CO2 emissions of rice phyllosphere at night time can be promoted evidently from it.

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Toxic Inorganic Heavy Metals and their Mitigation in Asian Soils

Dehlavi S., Eslamikhah Z. and Panwar B.S.

Unfortunately, with the increasing three dimensional problems (population, pollution and poverty) the Asian soils are under heavy pressure which may lead to their sickness and unacceptable toxic levels of heavy metals in future. Considerable amounts of the potentially toxic heavy metals – Cadmium, Nickel and Molybdenum can be introduced into soils via anthropogenic pathways such as dumping industrial effluents and agricultural application of sewage sludge, use of agro-chemicals and applied commercial fertilizers. Soils contaminated with toxic metals pose a major environmental and human health problem which needs an effective and affordable technological solution. Keeping in the views of above problems for the sustainable clean ups of environment/soils from these potentially toxic heavy metals, today’s techniques and strategies include phytoremediation1. It is widely viewed as ecologically responsible alternative to physico-chemical remediation methods. It has a strong potential as a natural, solar driven remediation approach for the treatment of soils contaminated with heavy metals. It is a practical and commercially viable new green emerging technology for environmental/soils reclamations for both organic and inorganic contaminants. Hyper accumulation of metals by plants is a remarkable phenomenon which uses one basic concept: the plant takes the pollutant through the roots. The pollutant can be stored in the plant (phytoextraction), volatilized by plant (phytovolatization), metabolized by the plant (phytodegradation) or any combination of the above.

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Synthetic strategies and pharmaceutical importance of structurally modified chitosans

Kumar Kapil, Nayak Surendra Kumar, Narang Rakesh, Gupta Vivek and Chopra Harish Kumar

Over the last few decades, chitosan and its derivatives have been used for various applications such as pharmaceutical, biomedical, agrochemical etc. These derivatives have variable physicochemical properties which are associated with their structural differences. There is regular progress in the structural modification of polymers to produce their novel derivatives. Here, we outline some important synthetic strategies for structural modifications of chitosans and their altered physicochemical properties for application in the field of pharmaceuticals.

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