Asit K. Das

Photodegradation of carbofuran

Abstract Carbofuran (2,3-dihydro-2,2 dimethyl benzofuranyl-7-yl-methyl carbamate, I) when irradiated by sunlight in different solvents furnished several photoproducts. Eleven compounds have been characterized, out of which nine compounds (II to X) by GC/MS and two compounds (XI and XII) by direct comparison with authentic samples. Another two compounds were isolated in pure form and identified by MS and NMR analysis. The main degradation pathways involved hydrolysis, oxidation, methylation, chlorination and rearrangement. The plausible pathway of photodegradation of carbofuran has been depicted.

Studies on the photodegradation of carbofuran

Photodegradation of the insecticide, carbofuran (I) in different organic solvents under sunlight furnished nine photoproducts (II-X). One compound (X) was isolated in pure form and characterized by MS and 1H-NMR evidence. The structures of eight other photoproducts (II-IX) were arrived at from GC-MS analysis.

Chemical Composition of Potato at Harvest and After Cold Storage

ABSTRACT In order to improve potato (Solanum tuberosum L.) genotypes through selection or breeding it is helpful to determine the chemical composition of tubers. Eleven potato genotypes were tested at harvest and after 6 months of cold storage for levels of water, starch, sugar, protein, trypsin inhibitor, oxalate, vitamin C, phenol, carotene, potassium, magnesium, calcium, phosphorus, iron, zinc, and manganese. Almost all chemical compounds except sugar, trypsin inhibitor, and phenol decreased significantly during cold storage. A large number of significant correlations between chemical compounds indicate biochemical relationships. Principal component analysis, which explained 74.81 and 85.60% of variance at the fresh market and after cold storage, respectively, along with results of ANOVA indicated that cv. Diamond appeared to be the most promising candidate from which improved lines could be obtained. Discriminant function analysis indicated that 7 of 16 variables distinguished between tubers at the fresh market state and after cold storage.

Nano-fabricated materials in cancer treatment and agri-biotech applications: Buckyballs in quantum holy grails

New ideas in the development of the intelligent nanomaterials miniaturized at the nanometer sizes gained substantial interest because of the wide range of their technological purposes. The recognition of the ultimate limits of computation has also lead computer scientists to seek inspiration from nanobiology. Because living organisms function with nanoscale buildings blocks and exploit collective quantum effects and thermal energy. This is necessary for the survival in its “living” thermodynamic status. The hope to break the barrier of miniaturization seems to lie in the knowledge of the self-organization mechanism of living objects. Furthermore, knowledge about the mesoscopic scale might be able to explain the self-assembly and the working regime of the simplest organisms created by nature. In solid-state physics and electronics, a large variety of different non-equilibrium phenomena accompany with the spontaneous self-assembly of the spatial and the spatio-temporal patterns in the nano-size objects. First, we present a recent update of the different nanomaterials experimentally or commercially produced which have been successfully applied in complex biological systems. Finally, we give examples of our pioneering research on ‘cancer’ and ‘agricultural biotechnology’ to provide readers better vistas about the enormous growth potential of nanotechnology in coming years. We have developed an international nanosilica network to do research on cancer biology and agricultural biotechnology. Surface modified hydrophobic and lipophilic nanosilica developed by us has already attracted huge investments in different parts of the globe. We also propose a nanoparticle assisted cybernetic approach, which could be used for early cancer detection in future.

Peroxidase and polyphenoloxidase activities and phenol content in fruit of eggplant and their relationship to infestation by shoot and fruit borer.

The shoot and fruit borer (Leucinodes orbonalis Guen.) does severe damage to eggplant (Solanum melongena L.). In order to predict the level of fruit infestation and perhaps correlate it to specific biochemical characteristics, the basis of resistance against the shoot and fruit borer in eggplant was investigated. Seven cultivars of eggplant were sampled at 10, 15, 20, and 25 days after flowering (DAF) for peroxidase (PO) and polyphenoloxidase (PPO) activity and at 15, 20, and 25 DAF for phenol content. Stepwise multiple regression analysis revealed that there was a lack of correlation between fruit infestation and PO activity. However, a correlation between fruit infestation; PPO activity at 15, 20, and 25 DAF; and phenol content at 15 and 20 DAF was observed. Principal components analysis indicated that BCB-38 was the best performing cultivar and can likely be used as improved genetic material in future breeding programs.

Nutrient and Antinutrient Composition of Cormels of Colocasia esculenta var. antiquorum

Abstract In order to improve cultivars through selection or breeding, the nutrient and antinutrient, i.e., trypsin inhibitor, total oxalate, soluble oxalate and calcium oxalate, compositions of cormels of twenty cultivars of Colocasia esculenta var. antiquorum were determined. The fat, sugar, starch and crude protein content in fresh cormels varied from 0.08-0.98, 0.2-1.5, 7.5-24.8 and 1.0-2.8%, respectively. Cormels provide 166-519 kJ of energy/100 g fresh weight. Moreover, cormels are a good source of minerals, including potassium, calcium, phosphorus and iron, a moderate source of zinc and copper, and an inadequate source of manganese. The contents of the trypsin inhibitor, total oxalate, soluble oxalate and calcium oxalate varied from 52-1020 Trypsin Inhibitory Units (TIU).g −1,8-130,4-89 and4-93 mg/100 g, respectively. Principal component analysis indicated that the cv. ‘Sonajuli’ appears to be a promising candidate to provide genetic material from which improved lines can be developed.

Peroxidase, Polyphenoloxidase, Total Phenol and Protein Content in Leaf Tissues of Colocasia esculenta var. antiquorum and Their Relationship to Phytophthora Leaf Blight Disease

ABSTRACT Specific activities of peroxidase, polyphenoloxidase, total phenol and total protein content in healthy and diseased leaves of tolerant and susceptible cultivars of Taro (Colocasia esculenta var. antiquorum) to Phytophthora leaf blight disease were studied. Tolerant cultivars of Colocasia had 100% and 81% increase of total phenol and protein, respectively, when compared to susceptible cultivars. The specific activity of peroxidase remained higher while that of polyphenoloxidase remained lower in tolerant cultivars as compared to susceptible cultivars. Adjusting coefficient of determination (R2) at 0.99, the multiple regression equation was derived, which indicated that tolerance was related to all of the components measured.

Quality Evaluation of Cormels of New Germplasm of Taro

ABSTRACT There has been little qualitative evaluation of nutrients in taro Colocasia esculenta var. antiquorum L. The improvement of cultivars and human diet through selection or breeding for 1) nutrient; 2) antinutrient; i.e., trypsin inhibitor, total oxalate, soluble oxalate, and calcium oxalate; 3) antioxidant; i.e., vitamin C, carotene, and phenol compositions; and 4) activities of two antioxidative enzymes, peroxidase, and catalase and one oxidative enzyme, polyphenoloxidase, of cormels of cultivars of taro were determined. Correlation analysis indicated biochemical relationships between chemicals. Principal component analysis, explaining 64.93% of variance, indicated that cv. BCC 25 appeared to be the most promising candidate from which improved lines could be obtained.

Dissipation and effect of chlorophenoxy herbicide on plant pigments and carbohydrates of sunflower (Helianthus annuus L.)

The dissipation pattern of the chlorophenoxy herbicides (2,4‐D and 2,4,5‐T) residues in sunflower plants (Helianthus annuus L.) has been studied along with its effect on the changes of plant pigments (chlorophyll‐a,b, total chlorophyll, carotene and anthocyanin), sugar and starch in different parts of the plant. The residues of 2,4‐D and 2,4,5‐T remained for larger period of time (10 days) at higher concentrations than the lower concentration. The concentrations of chlorophylls and carotene were found to be reduced with the application of both 2,4‐D and 2,4,5‐T. But the chlorophyll concentrations were slowly normalized accompanied with the reduction of the herbicide residues. For anthocyanin, there was no significant effect. In case of carbohydrate, the sugar concentration was found to be raised by all doses in leaf and stem. The change in starch content in different plant parts did not follow an uniform pattern at different doses of herbicides.

Effect of carbofuran on carbohydrate, protein and trace elements in rice (Oryza sativa L.)

Variability in concentration of reducing sugar, starch, protein and some trace elements (Zn, Fe, Mn & Cu) with the application of two doses of carbafuran‐3G (1 kg a.i. and 2 kg a.i. ha‐1 ) during development period of paddy cv. Ratna from 0 (panicle initiation) to 35 days after flowering (DAF) was studied. Application of carbofuran‐3G @ 1 kg a.i. ha‐1 increased maximum concentration of starch, Fe and Mn while the higher dose raised reducing sugar, protein, Zn and Cu at harvesting stage. Correlation coefficient among all the components were also studied on all the dates of collection.