A nontoxic antitumour compound from the leaves of Bauhinia scandens characterized as 1-O-alkyl glycerol by gas–liquid chromatography and evaluation of its antitumour property by Brine Shrimp bioassay     

Asish Ghosh Hazra  Padma Chatterjee 《Industrial Crops and Products》2008,27(1):39-43

This is a report of extraction and identification of 1-O-alkyl glycerol present in the dried leaves of Bauhinia scandens. Fifty percent aqueous ethanolic extract of the plant at room temperature was fractionated over petroleum ether and diethyl ether. The diethyl ether soluble fraction showed positive bioactivity in Brine Shrimp bioassay. Isolation and purification of the active principle was subsequently done from diethyl ether fraction. The diethyl ether fraction was separated into acidic and neutral part. The acid free fraction was screened to be positive in Brine Shrimp bioassay. The NMR spectra (in CDCl₃) indicated the probability of its lipoidal nature. The total lipid fraction was resolved into neutral, glyco, and phospho-lipids by column chromatography. Only the neutral fraction showed positive response to Brine Shrimp toxicity test, out of which again a Brine Shrimp positive fraction was separated by thin layer chromatography and identified as 1-O-alkyl glycerol. This fraction was acetylated and GLC analysis of the 1-O-alkyl-2,3-diacetyl glycerol was done. Our results demonstrate that the work may be cited as a nonhazardous and nonchemical management of therapeutic importance.  相似文献   

Understanding the infrared spectrum of bare CH5+     

Asvany O  P PK  Redlich B  Hegemann I  Schlemmer S  Marx D 《Science (New York, N.Y.)》2005,309(5738):1219-1222

Protonated methane, CH5+, continues to elude definitive structural assignment, as large-amplitude vibrations and hydrogen scrambling challenge both theory and experiment. Here, the infrared spectrum of bare CH5+ is presented, as detected by reaction with carbon dioxide gas after resonant excitation by the free electron laser at the FELIX facility in the Netherlands. Comparison of the experimental spectrum at approximately 110 kelvin to finite-temperature infrared spectra, calculated by ab initio molecular dynamics, supports fluxionality of bare CH5+ under experimental conditions and provides a dynamical mechanism for exchange of hydrogens between CH3 tripod positions and the three-center bonded H2 moiety, which eventually leads to full hydrogen scrambling. The possibility of artificially freezing out scrambling and internal rotation in the simulations allowed assignment of the infrared spectrum despite this pronounced fluxionality.  相似文献   

Soil fertility management in the mid-hills of Nepal: Practices and perceptions   总被引：1，自引：0，他引：1  

Colin?J.?PilbeamEmail author  Sudarshan?B.?Mathema  Peter?J.?Gregory  Padma?B.?Shakya 《Agriculture and Human Values》2005,22(2):243-258

Sustaining soil fertility is essential to the prosperity of many households in the mid-hills of Nepal, but there are concerns that the breakdown of the traditional linkages between forest, livestock, and cropping systems is adversely affecting fertility. This study used triangulated data from surveys of households, discussion groups, and key informants in 16 wards in eastern and western Nepal to determine the existing practices for soil fertility management, the extent of such practices, and the perception of the direction of changes in soil fertility. The two principal practices for maintaining soil fertility were the application of farmyard manure (FYM) and of chemical fertilizer (mainly urea and diammonium phosphate). Green manuring, in-situ manuring, slicing terrace risers, and burning plant residues are rarely practiced. FYM usage was variable with more generally applied to khet land (average 6053 kg fresh weight manure ha^–1) than to bari land (average 4185 kg fresh weight manure ha^–1) with manure from goats and poultry preferred above that from cows and buffaloes. Almost all households (98%) apply urea to khet land and 87% to bari land, with 45% applying diammonium phosphate to both types of land. Application rates and timings of applications varied considerably both within and between wards suggesting poor knowledge transfer between the research and farming communities. The benefits of chemical fertilizers in terms of ease of application and transportation in comparison with FYM, were perceived to outweigh the widely reported detrimental hardening of soil associated with their continued usage. Among key informants, FYM applied in conjunction with chemical fertilizer was the most popular amendment, with FYM alone preferred more than chemical fertilizer alone – probably because of the latters long-term detrimental effects. Key informant and householder surveys differed in their perception of fertility changes in the last decade probably because of differences in age and site-specific knowledge. All key informants felt that fertility had declined but among households, only about 40% perceived a decline with the remainder about evenly divided between no change and an increase. Householders with small landholdings (< 0.5 ha) were more likely to perceive increasing soil fertility while those with larger landholdings (> 2 ha) were more likely to perceive declining fertility. Perceived changes in soil fertility were not related to food self-sufficiency. The reasons for the slow spread of new technologies within wards and the poor understanding of optimal use of chemical fertilizers in conjunction with improved quality FYM may repay further investigation in terms of sustaining soil fertility in this region.Colin Pilbeam graduated from the University of Oxford with an MA in Agriculture and Forest Sciences. He spent 11 years as a Post-Doctoral Research Fellow in the Department of Soil Science, The University of Reading researching nitrogen and water dynamics in cropping systems in Kenya, Syria, and Nepal. He is now the manager of research programs at Cranfield School of Management.Sudarshan Bhakta Mathema is a senior agricultural economist based in Kathmandu, Nepal. After serving the Ministry of Agriculture and Cooperatives, in Nepal for 23 years, he joined the UNs Food and Agriculture Organization as the Farming Systems Economist for 2years. Currently, Dr. Mathema is the Manager of the Hill Agriculture Research Project with the Department for International Development, UK. Dr Mathema has major expertise in the fields of farming systems research and development, participatory research and development, competitive grant systems, sustainable rural livelihoods, impact assessment, project management and implementation, agricultural extension methods, and various types of socio-economic research. He has worked as a consultant for various national and international institutes. He has published papers and reports in the field of agriculture, particularly focusing on Nepal.Peter Gregory has been the Professor of Soil Science at the University of Reading since 1994. His research focuses on the interactions between plant roots and soils and on the development of sustainable systems of crop production. He has worked in Australia, Syria, Nepal, India, and West Africa and is the chair of Global Environmental Change and Food Systems – an international research project on food security.Padma Bahadur Shakya is an Agricultural Economist who has worked for the Department of Agriculture under the Ministry of Agriculture and Cooperatives in Nepal for more than 20 years. He has also been a short-term consultant for various national and international organizations such as FAO, the UNs World Food Programme, Swiss Development Corporation, Asian Development Bank, JICA, HARP, and several local NGOs. Currently, he is affiliated with the Agriculture Perspective Plan Support Programme, implemented by the Ministry of Agriculture and Cooperatives.  相似文献   

Calcium-dependent stress maintenance without myosin phosphorylation in skinned smooth muscle   总被引：4，自引：0，他引：4  

M Chatterjee  R A Murphy 《Science (New York, N.Y.)》1983,221(4609):464-466

Stress development depended on calcium-stimulated myosin phosphorylation in an arterial smooth muscle preparation in which the concentration of calcium was controlled. However, developed stress was maintained at a concentration of calcium that did not support phosphorylation. These results, in conjunction with other evidence, suggest that the interaction of two regulatory mechanisms with different calcium sensitivities regulate both stress and the rate and energetics of contraction.  相似文献   

Broadband modulation of light by using an electro-optic polymer     

Lee M  Katz HE  Erben C  Gill DM  Gopalan P  Heber JD  McGee DJ 《Science (New York, N.Y.)》2002,298(5597):1401-1403

A major challenge to increasing bandwidth in optical telecommunications is to encode electronic signals onto a lightwave carrier by modulating the light up to very fast rates. Polymer electro-optic materials have the necessary properties to function in photonic devices beyond the 40-GHz bandwidth currently available. An appropriate choice of polymers is shown to effectively eliminate the factors contributing to an optical modulator's decay in the high-frequency response. The resulting device modulates light with a bandwidth of 150 to 200 GHz and produces detectable modulation signal at 1.6 THz. These rates are faster than anticipated bandwidth requirements for the foreseeable future.  相似文献   

Alkaloid Spectrum of Different Germplasm Lines in Opium Poppy (Papaver somniferum L.)     

Sudhir Shukla  S. P. Singh  H. K. Yadav  A. Chatterjee 《Genetic Resources and Crop Evolution》2006,53(3):533-540

The opium latex of 1470 individual plant samples of 98 germplasm lines were screened for five major economic alkaloids. The alkaloids profile showed that morphine content ranged from 9.20–20.86% with an average of 15.00 ± 0.267. Codeine ranged from 1.69–6.48% with arithmetic mean of 3.35 ± 0.091, thebaine from 0.52–7.95% with an average of 2.27 ± 0.116. Narcotine ranged from 8.79–17.97% with an average 8.79 ± 0.266 and papaverine content ranged from 0.00–6.07% with an average 1.18 ± 0.167 in over all the germplasm lines. The content of different alkaloids categorized into class interval which exhibited that maximum number of plants and accessions for morphine content fall in group of 10–15% followed by 15–20%, for codeine content in group of 2–4% followed by 4–6%, for thebaine content in 1–2% followed by 2–4%, for narcotine in 5–10% followed by 10–15% and for papaverine content 0–2%. 24 germplasm lines had morphine content above 16.0%. Similarly, 37 germplasm lines for codeine and 13 for thebaine showed consistently high content, i.e., above 3%. 33 germplasm lines had narcotine content above 9% and 20 lines exhibited papaverine content above 2%. Line BR 316 was found unique having thebaine content 6.27–9.33%. The probable reasons of increase or decrease of different alkaloids based on their biosynthetic pathway has been discussed in detail.  相似文献   

Effect of potassium application on the transformation of zinc fractions in soil and on the zinc nutrition of wetland rice     

Biswapati Mandal  P. S. Das Pattanayak  A. Samanta  A. K. Chatterjee 《植物养料与土壤学杂志》1996,159(5):413-417

The effect of different levels of K application on the transformation of native as well as applied Zn fractions in a rice-growing soil was studied under two moisture regimes viz. waterlogged and alternate waterlogged and saturation. Application of K caused an increase in the water-soluble plus exchangeable, organically complexed and carbonates, and other acid-soluble mineral fractions of native soil Zn. Application of K also caused an increase in the transformation of applied Zn into all the above three fractions of the element in soil. The above effects of K were more pronounced in soil under waterlogged than under alternate waterlogged and non-waterlogged moisture regimes. The results of a greenhouse experiment showed that K application caused an increase in Zn uptake and per cent utilization of both native and added Zn by rice. This was attributed to the increase in the water-soluble plus exchangeable and organically complexed forms of Zn in soil due to K application.  相似文献   

ISSR profiling of Indian cultivars of mulberry (Morus spp.) and its relevance to breeding programs     

K. Vijayan  S. N. Chatterjee 《Euphytica》2003,131(1):53-63

Mulberry, Morus spp. has a wide range of use, the chief among them is to feed the silk producing caterpillar Bombyx mori L. (Bombycidae; Bombycoidea). As a homeland of mulberry, India has a number of indigenous mulberry species, of which a few are widely cultivated. In the present investigation genetic distance among such eleven mulberry cultivars originated from six different states of India covering a wide geographic area extending from 15^° N to 32^° N latitude and 72^°E to 89^°E longitude was studied using inter-simple sequence repeat primers. Out of the 20primers tested, 13 primers, viz, nine di-nucleotide, three tri-nucleotide and one penta-nucleotide repeats, gave clear and reproducible band profiles. While the (AT)_n rich primers could not amplify the DNA, the (GA)n, (AC)n and (AG)n rich primers gave excellent amplification profiles. The genetic distance among the cultivars varied from a minimum of 0.053, between Punjab local and Bombay local, to a maximum of 0.431, between Almora local andSujanpur-5. Clustering of the cultivars according to nearest neighbor method created three groups. The north-Indian cultivars made a separate and distinct group while the cultivars originated from eastern and southern India occupied a distinct position. Almora local was found quite different from others. The first two canonical functions identified through discriminant function analysis accounted for 91.2% of the total variability. Distribution of cultivars belonging to six different zones on canonical matrix realized from Discriminant Function Analysis (DFA) revealed wider variability for West Bengal, Karnataka and Punjab which reaches the group centroids of Uttar Pradesh and Himachal Pradesh. This attests to the past contribution of West Bengal in east and Karnataka in south towards development of mulberry cultivars indifferent parts of India. Step-wise linear regression analysis, further, identified two markers (825.₁₄₀₀ and835.₇₅₀) associated with leaf yield, which also satisfied the Beta estimation, thereby testifying strong association of these two markers with leaf yield. This finding along with the classification of the eleven cultivars bear strong relevance to mulberry breeding for different agro climatic areas. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Micro-nutrient pools and their mobility in relation to land-use system in a cold high altitude Himalayan mountainous region     

Sharma  Sandeep  Singh  Pritpal  Angmo  Padma  Dhaliwal  S. S. 《Agroforestry Systems》2021,95(8):1395-1412

Agroforestry Systems - Land-use change significantly impacts soil micro-nutrients distribution and transformations due to their inefficient scale- and location-specific management in different...  相似文献   

E‐commerce,Transportation, and Economic Geography     

William P. Anderson  Lata Chatterjee  T.R. Lakshmanan 《Growth and change》2003,34(4):415-432

ABSTRACT This paper explores possible ways in which growth in Internet retailing (e‐retailing) may affect the spatial distribution of economic activities. After a brief overview of e‐retailing, a categorization of possible spatial impacts is introduced. These include impacts on the retail industry, such as substitution of e‐retail for brick‐and‐mortar retail, impacts on transportation, such as substitution of freight transportation for personal transportation in goods delivery, and pervasive impacts that affect the whole economy. The latter category includes uniform delivered pricing, spatial leveling of accessibility, and marketing strategies that target individuals rather than regions. The question of whether e‐retailing and brick‐and‐mortar retailing are truly substitutes is taken up in the next section, along with potential implications of multi‐channel retailing. The final section of the paper defines some critical research directions.  相似文献