Browsing by Author "Pandey, Richa"

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2-Hydroxyacetophenone, the main component of the essential oil of the roots of Carissa opaca Stapf ex Haines
(Taylor & Francis Group, 2009) Mallavarupu, Gopal R.; Mishra, Raghvendra K.; Chaudhary, Swati; Pandey, Richa; Gupta, Sarika; Kumar, Sushil
The volatile oil obtained by hydrodistillation of the roots of Carissa opaca was analyzed by GC and GC/MS to study its composition. Thirty-five compounds representing 98.3% of the oil were identified. Si-gel chromatography of the oil yielded 2-hydroxyacetophenone, which was characterized by spectral methods (1H-, 13C-NMR and mass), as the main component, amounting to 89.5% of the oil.
Analysis of linalool content in the inflorescence (flower) essential oil and leaf oil of Lippia alba cultivar ‘Kavach’
(Taylor & Francis Group, 2010) Mishra, Raghvendra K.; Chaudhary, Swati; Pandey, Richa; Gupta, Sarika; Mallavarapu, Gopal R.; Kumar, Sushil
Lippia alba cultivar ‘Kavach’ is an aromatic, multi-branched, trailing, deep-rooted shrub that can be planted on slopes to control soil erosion. Cuttings of this genotype were planted on the edges of field plots developed by depositing agricultural soil on the rocky terrain of Aravalli mountain range land on which the Institute is located in New Delhi. Shoots harvested several times a year in the third, fourth and fifth year from planting were sampled for leaves and flowers bearing inflorescences to determine their biomass yield. The inflorescences and leaves sampled from the harvests of third year were analyzed by GC and GC/MS for their oil quality. Altogether 55 compounds were identified in leaf and inflorescence oils; a set of 47 compounds made up 96.3% of the leaf oil and 46 compounds made up 97.0% of inflorescence oil. The concentrations of linalool and 1,8-cineole were 67.7% and 6.4% in the leaf oil, whereas these were 79.3% and 5.2%, respectively, in inflorescence oil. The inflorescence oil also contained cis- and trans-linalool oxides (2.8%). The importance of the flower oil of L. alba cultivar ‘Kavach’ as a linalool-rich oil resource is discussed in terms of traditional sources of such oil and unique features of the cultivar.
Characterization of variation and quantitative trait loci related to terpenoid indole alkaloid yield in a recombinant inbred line mapping population of Catharanthus roseus
(Indian Academy of Sciences, 2012) Sharma, Vishakha; Chaudhary, Swati; Srivastava, Suchi; Pandey, Richa; Kumar, Sushil
Improved Catharanthus roseus cultivars are required for high yields of vinblastine, vindoline and catharanthine and/or serpen- tine and ajmalicine, the pharmaceutical terpenoid indole alkaloids. An approach to derive them is to map QTL for terpenoid indole alkaloids yields, identify DNA markers tightly linked to the QTL and apply marker assisted selection. Towards the end, 197 recombinant inbred lines from a cross were grown over two seasons to characterize variability for seven biomass and 23 terpenoid indole alkaloids content-traits and yield-traits. The recombinant inbred lines were genotyped for 178 DNA markers which formed a framework genetic map of eight linkage groups (LG), spanning 1786.5 cM, with 10.0 cM average intermarker distance. Estimates of correlations between traits allowed selection of seven relatively more important traits for terpenoid indole alkaloids yields. QTL analysis was performed on them using single marker (regression) analysis, simple interval mapping and composite interval mapping procedures. A total of 20 QTL were detected on five of eight LG, 10 for five traits on LG1, five for four traits on LG2, three for one trait on LG3 and one each for different traits on LG three and four. QTL for the same or different traits were found clustered on three LG. Co-location of two QTL for biomass traits was in accord of correlation between them. The QTL were validated for use in marker assisted selection by the recombinant inbred line which transgressively expressed 16 traits contributory to the yield vinblastine, vindoline and catharanthine from leaves and roots that possessed favourable alleles of 13 relevant QTL.
Co-regulation of biomass partitioning by leafblade morphology genes AFILA, MULTIFOLIATE-PINNA, TENDRIL-LESS and UNIFOLIATA in grain pea Pisum sativum
(Indian National Science Academy, 2010) Kumar, Sushil; Mishra, Raghvendra Kumar; Chaudhary, Swati; Pandey, Richa; Yadav, Gitanjali
In grain pea Pisum sativum, 16 genotypes constructed by combining wild type and mutant alleles of MULTIFOLIATE- PINNA (MFP), AFILA (AF), TENDRIL-LESS (TL) and UNIFOLIATA (UNI) genes, which differed in leaf blade morphology, were quantitatively phenotyped for allometry. The biomass partitioning among root, stem, stipule, leaf blade and seeds was unique for these genotypes suggesting that MFP, AF, TL and UNI genes determined leaf blade and plant architecture. Gene actions were inferred on the basis of mutant phenotypes. Biomass of all the organs was found to be increased in the tl single mutant. The af mutation singly and in combination with mfp, mfp tl, mfp uni-tac or mfp tl uni-tac decreased biomass of all the organs. Allocation of biomass to leaves was increased at the expense of that to seeds or seeds and stems by a single mfp mutation or in combination with uni-tac, af tl, tl uni-tac and af tl uni-tac mutations. The AF and MFP functions are essential in pea cultivars for high yield of grains.The mechanism for simultaneous control of leaf blade and plant architecture suggested by mutant phenotypes has three elements. The MFP, AF, TL and UNI genes exercise control over meristematic activity in all the organs. Their determination of leaf blade morphology and size affect net photosynthesis or metabolite supply. The quantities of available metabolites determine numbers and sizes of organs or partitioned total biomass. The tl allele is identified as a genetic marker/determinant for breeding tendril-less prolific pea cultivars for obtaining herbage and grains in high yields.
Correspondence between flowers and leaves in terpenoid indole alkaloid metabolism of the phytoplasma-infected Catharanthus roseus plants
(Springer, 2014) Srivastava, Suchi; Pandey, Richa; Kumar, Sushil; Nautiyal, Chandra Shekhar
Several plants of Catharanthus roseus cv 'leafless inflorescence (lli)' showing phenotype of phytoplasma infection were observed for symptoms of early flowering, virescence, phyllody, and apical clustering of branches. Symptomatic plants were studied for the presence/absence and identity of phytoplasma in flowers. Transcription levels of several genes involved in plants' metabolism and development, accumulation of pharmaceutically important terpenoid indole alkaloids in flowers and leaves and variation in the root-associated microbial flora were examined. The expression profile of 12 genes studied was semi-quantitatively similar in control leaves and phytoplasma-infected leaves and flowers, in agreement with the symptoms of virescence and phyllody in phytoplasma-infected plants. The flowers of phytoplasma-infected plants possessed the TIA profile of leaves and accumulated catharanthine, vindoline, and vincristine and vinblastine in higher concentrations than leaves. The roots of the infected plants displayed lower microbial diversity than those of normal plants. In conclusion, phytoplasma affected the biology of C. roseus lli plants multifariously, it reduced the differences between the metabolite accumulates of the leaves and flowers and restrict the microbial diversity of rhizosphere.
Ebola virus disease: Biology, diagnosis, treatment and prevention of epidemics
(Indian National Science Academy, 2017) Kumar, Sushil; Kumari, Renu; Pandey, Richa; Sharma, Vishakha
Ebola virus disease (EVD) is a highly lethal contagious disease caused by the negative RNA strand Ebola virus. Reservoired in wild forest animals of Africa, Ebola virus infects humans that come in direct contact of diseased animals and outbreaks of EVD result from person to person spread of infection. A recent EVD outbreak in West Africa has killed several thousand persons. Since Ebola infection will persist in animals, EVD epidemics are expected to continue to occur in future. Infected travellers from Africa can initiate/import outbreaks in countries of other continents. This review describes the properties of the Ebola virus and EVD, the ongoing attempts to develop diagnostics, vaccines and medicines for prevention and cure of EVD and the supportive care that saves some EVD patients. Also discussed are measures that can stop and prevent EVD outbreaks. Need for inclusion of EVD in the education, research, drug and medical equipment manufacturing programmes, of the densly populated countries such as India, is emphasised.
Lychee-associated hypoglycaemic encephalopathy: A new disease of children described in India
(The National Academy of Sciences, India, 2020) Kumar, Sushil; Kumari, Renu; Pandey, Richa
Fruits of lychee tree (Litchi sinensis), extensively horticultured in India, China and many other countries, are delicious and possess many nutritious and medicinal properties. In India and other Asian countries, in lychee harvest season, outbreaks have been occurring of rapidly developing hypoglycaemia, encephalopathy, seizures and cerebral oedema in young children when they ingest lychee fruit arils in large numbers on empty stomach. It has been shown that the acute neurological illness is hypoglycaemic encephalopathy, caused by the actions of hypoglycin A (HGA) and methylenecyclopropylglycine (MCPG), the non-protein L-amino acids present in the edible arils of lychee fruits. Both HGA and MCPG phytotoxins are known to disrupt the pathways of β-fatty acid oxidation and gluconeogenesis in human body cells, result in accumulation of many undesirable metabolites of the blocked energy generating pathways, and altogether produced the often fatal hypoglycaemic illness. Here, the related work is summarized and commented upon and prospective genetical interventions in Litchi sinensis to eradicate the problem are outlined. Toxin-deficient lychee genotypes need to be developed by screening of germplasm accessions, and use of conventional and new site-directed mutagenesis technique of plant breeding. Lychee trees that produce super-toxin-rich (× 10 average toxin concentration) fruits are required to be identified and tagged to stop consumption of their fruits. New plantings must use toxin-deficient (low-toxin) lychee genotypes.
New insight-guided approaches to detect, cure, prevent and eliminate malaria
(Springer, 2015) Kumar, Sushil; Kumari, Renu; Pandey, Richa
New challenges posed by the development of resistance against artemisinin-based combination therapies (ACTs) as well as previous first-line therapies, and the continuing absence of vaccine, have given impetus to research in all areas of malaria control. This review portrays the ongoing progress in several directions of malaria research. The variants of RTS,S and apical membrane antigen 1 (AMA1) are being developed and test adapted as multicomponent and multistage malaria control vaccines, while many other vaccine candidates and methodologies to produce antigens are under experimentation. To track and prevent the spread of artemisinin resistance from Southeast Asia to other parts of the world, rolling circle-enhanced enzyme activity detection (REEAD), a time- and cost-effective malaria diagnosis in field conditions, and a DNA marker associated with artemisinin resistance have become available. Novel mosquito repellents and mosquito trapping and killing techniques much more effective than the prevalent ones are undergoing field testing. Mosquito lines stably infected with their symbiotic wild-type or genetically engineered bacteria that kill sympatric malaria parasites are being constructed and field tested for stopping malaria transmission. A complementary approach being pursued is the addition of ivermectin-like drug molecules to ACTs to cure malaria and kill mosquitoes. Experiments are in progress to eradicate malaria mosquito by making it genetically male sterile. High-throughput screening procedures are being developed and used to discover molecules that possess long in vivo half life and are active against liver and blood stages for the fast cure of malaria symptoms caused by simple or relapsing and drug-sensitive and drug-resistant types of varied malaria parasites, can stop gametocytogenesis and sporogony and could be given in one dose. Target-based antimalarial drug designing has begun. Some of the putative next-generation antimalarials that possess in their scaffold structure several of the desired properties of malaria cure and control are exemplified by OZ439, NITD609, ELQ300 and tafenoquine that are already undergoing clinical trials, and decoquinate, usnic acid, torin-2, ferroquine, WEHI-916, MMV396749 and benzothi