Investigation on phytochemical constituents and biological potential of some traditional medicinal plants

Plants and microorganisms provide the pharmaceutical industry with some of the most important sources of components for the research of new medications This thesis involves the study of three medicinal plants belonging to three different important families viz, Cyperus rotundus (Cyperaceae), Stereospermum colais (Bignoniaceae) as well as the well known medicinal plant Zingiber officinale (Zingiberaceae) as the third. The first chapter gives an overview of biologically active natural products with special reference to antioxidant, antidiabetic, anti-inflammatory and antimicrobial molecules from terrestrial sources. Chapter 2 of the thesis deals with the isolation of phytochemical constituents of the medicinal plant Cyperus rotundus and its antioxidant and radical scavenging potential. Chapter 3 of the thesis describes the studies on the roots of Stereospermum colais, A Bignoniaceae plant belonging to the genus Stereospermum which is used extensively. Chapter 3 of the thesis describes the studies on the roots of Stereospermum colais, a Bignoniaceae plant belonging to the genus Stereospermum which is used extensively in Ayurveda. Chapter 4 describes the biological potential of rhizomes of Zingiber officinale. Ethyl acetate extract of ginger (EAG) possessed antioxidant activity as is evident from the results of various in vitro assays compared to other extracts .In conclusion, medicinal plants Cyperus rotundus and Stereospermum colais have been analysed for their phytochemical constituents. Also, the positive results obtained from biological activity studies such as antioxidant, anti-inflammatory and antimicrobial activity on the isolated compounds/extracts add on to the medicinal properties of these plants. Apart from that, ethyl acetate extract of Zingiber officinale (ginger) rhizomes has been shown to have very good biological potential including glucose lowering and adipocyte differentiation inhibitory effect.Cochin university of Science & technolog

Microstructural, thermal and electrical properties of electron irradiated Li₂CO₃ doped PVA

616-620Poly (vinyl alcohol) doped with Li2CO3 composite films have been prepared by solvent casting method and irradiated with energetic electrons. The FTIR study shows that the electron irradiation creates free radicals, chain scission and cross-linking within the polymer composite. The effect of these changes induces structural modifications and enhances the amorphosity of the composite, which has been studied using X-ray diffraction method. The thermal properties have been studied using thermogravimetric analysis and it has been found that the onset temperature (To) of decomposition increases up to 150 kGy and then decreases for higher doses. Using this data activation energy of the thermal decomposition has been determined which is in good corroborated with To values. This indicates that the cross-linking of polymer chains takes place in lower dose and the cleavage occurs at higher doses. The DC conductivity results show that the conductivity increases up to 1.0103×10-3S/cm for 300 kGy doses

Not Available

Not AvailableNIn this study, the efficacy of two entomopathogenic nematode species, Heterorhabditis indica and Steinernema asiaticum were evaluated against the larvae of the rice leaf folder, Cnaphalocrosis medinalis and the greater wax moth, Galleria mellonella. Combined inoculation of H. indica and S. asiaticum each at 75 IJs/larva resulted in faster larval mortality on C. medinalis (24.6 h) and G. mellonella (31 h). The percent larval mortality caused by H. indica alone was resulted significantly more (90% on G. mellonella and 60% on C. medinalis) than S. asiaticum (10% on G. mellonella and 40% on C. medinalis). Progeny produced by H indica and S. asiaticum was significantly more (84134 and 80458 IJs/larva respectively) on G. mellonella than they produced on C. medinalis larva (4843 and 4330 IJs/larva respectively). The combined use of entomopathogenic nematodes may offer an integrated approach to increase the efficacy of control of the rice leaf folder, Cnaphalocrosis medinalis and it could be a viable component in the Integrated Pest Management (IPM) where other control measures are ineffective or cannot be imposed.ot AvailableNot Availabl

Estimation of Land Surface Temperature to Study Urban Heat Island Effect using Landsat ETM

Abstract The urban air temperature is gradually rising in all cities in the world. One of the possible causes is the drastic reduction in the greenery area in cities. The distinguished climatic condition termed 'Urban Heat Island' (UHI) is developing in the rapidly urbanized cities. Vijayawada city of Andhrapradesh is experiencing rapid urbanization that has resulted in remarkable UHI. Understanding the distribution of Land Surface Temperature (LST) and its spatial variation will be helpful to decipher its mechanism and find out possible solution. This study tries to investigate and identify land use types which have the most influence to the increase of ambient temperature in Vijayawada city. For the present study Landsat ETM+ images of 2001 was obtained from USGS for the study area. Using bands 1-5 and 7 of the pre-processed images the land use / cover pattern was mapped by supervised classification with the maximum likelihood classification algorithm of ERDAS imagine 9.1 software. Five classes considered for the study are Built-up land, Barren Land, Water bodies, Agricultural fields and Vegetation. Normalized Difference Vegetation Index (NDVI) image was developed. The digital number of thermal infrared band is converted in to spectral radiance using the equation supplied by the Landsat user's hand book. The effective at-sensor brightness temperature is obtained from the spectral radiance using Plank's inverse function. The surface emissivity based on NDVI classes is used to retrieve the final LST. It was noted that maximum air temperature was observed in built up areas of the city and minimum temperatures are observed in areas where vegetation cover is more. Urban heat island phenomenon is evident from the LST images. NDVI is found to have negative correlation with LST. The study reveals that appropriate strategies are necessary for the sustainable management of the urban area. Key words: Urban Heat Island, Land Surface Temperature, Land Use/Cover, NDVI INTRODUCTION Urban growth and sprawl have severely altered the biophysical environment. Rapid urbanization has significant influence on different aspects of the quality of life and research in determining the patterns of urbanization and quantifying their impacts is the need of the hour. Unplanned urbanization an urban sprawl will directly affect the land use and land cover of the area. The changes in land use/cover include loss of agricultural lands, loss of forest lands, increase of barren area, increase of impermeable surface of the area because of the built up area, etc. Development of land use land cover is very much useful to the city planner and policy makers. For the sustainable urban ecosystems the amount of land required for growing the vegetation can be estimated from these studies. One of the major implications of urbanization is increase of surface temperature and development of Urban Heat Island. Surface temperature is increased by anthropogenic heat discharges due to energy consumption, increased land surface coverage by artificial materials having high heat capacities and conductivities, and the associated decrease in vegetation and water pervious surfaces which reduce the surface temperature through evapotranspiration. Landsat ETM images are widely used to observe and model the biophysical characteristics of the land surface. In addition to the development of Land use/cover maps band 6 of the Landsat imagery is useful for deriving the surface temperature. Several researchers used the Landsat imagery to develop land use/cover images as well as temperature images

Not Available

larval transcriptome of yellow stem borer was studiedABSTRACT The yellow stem borer (YSB), Scirpophaga incertulas, is a prominent pest in rice cultivation causing serious yield losses. The larval stage is an important stage in YSB, responsible for maximum infestation. However, limited knowledge exists on the biology and mechanisms underlying the growth and differentiation of YSB. To understand and identify the genes involved in YSB development and infestation, so as to design pest control strategies, we performed de novo transcriptome analysis at the first, third, fifth, and seventh larval developmental stages employing Illumina Hi-seq. High-quality reads (HQR) of 229 Mb were assembled into 24,775 transcripts with an average size of 1485 bp. Genes associated with various metabolic processes, i.e., detoxification mechanism [CYP450, GSTs, and carboxylesterases (CarEs)], RNA interference (RNAi) machinery (Dcr-1, Dcr-2, Ago-1, Ago-2, Sid-1, Sid-2, Sid-3, and Sid-1-related gene), chemoreception (CSPs, GRs, OBPs, and ORs), and regulators [transcription factors (TFs) and hormones] were differentially regulated during the developmental stages. Identification of stage-specific transcripts made it possible to determine the essential processes of larval development. Comparative transcriptome analysis revealed that YSB has not evolved much with respect to the detoxification mechanism, but showed the presence of distinct RNAi machinery. The presence of strong specific visual recognition coupled with chemosensory mechanisms supports the monophagous nature of YSB. Designed expressed sequenced tags-simple-sequence repeats (EST-SSRs) will facilitate accurate estimation of the genetic diversity of YSB. This is the first report on characterization of the YSB transcriptome and the identification of genes involved in key processes, which will help researchers and industry to devise novel pest control strategies. This study also opens up a new avenue to develop next-generation resistant rice using RNAi or genome editing approaches.Not Availabl

Influence of Cultivar and Maturity at Harvest on the Essential Oil Composition, Oleoresin and [6]-Gingerol Contents in Fresh Ginger from Northeast India

Severe flooding of the Brahmaputra River during the monsoon season and continuous rainfall in the northeast region (NER) of India cause an enormous loss of ginger crop every year. In this context, the present study investigates the variation in the essential oil composition and oleoresin and [6]-gingerol contents in 10 different fresh ginger cultivars harvested at 6- and 9-month maturity from five different states of NER. Monoterpenes, sesquiterpenes, and citral composition in the essential oil were evaluated to ascertain their dependence upon the maturity of ginger. Except Mizoram Thinglaidum, Mizoram Thingria, Nagaland Nadia, and Tripura I ginger cultivars, all other cultivars showed an increase in the citral content during the maturity that was observed for the first time. At 6-month maturity, a higher undecanone level was found in Nagaland Nadia (7.36 ± 0.61%), Tripura I (6.23 ± 0.61%), and Tripura III (9.17 ± 0.76%) cultivars, and these data can be used as a benchmark to identify those immature varieties. Interestingly, the Nagaland Nadia cultivar showed higher <i>ar</i>-curcumene (9.57 ± 0.58%) content than zingiberene (5.84 ± 0.24%), which was unique among all cultivars. Ginger harvested at 9-month maturity from the Tripura II cultivar had the highest citral content (22.03 ± 0.49%), and the Meghalaya Mahima cultivar had the highest zingiberene content (29.89 ± 2.92%). The oleoresin content was found to decrease with maturity in all cultivars, except Assam Fibreless and Manipur I. Moreover, the highest oleoresin (11.43 ± 0.58 and 9.42 ± 0.63%) and [6]-gingerol (1.67 ± 0.03 and 1.67 ± 0.05 g) contents were observed for Tripura II and Nagaland Nadia, respectively. This study suggests that Tripura and Nagaland are the most ideal locations in NER for ginger cultivation to obtain high yields of oleoresin and [6]-gingerol contents and harvesting at the 6-month maturation will compensate for the loss of ginger crop caused by the Brahmaputra River flooding in NER every year

Not Available

Not AvailableBacterial blight (BB) of rice caused by the pathogen Xanthomonas oryzae pv. oryzae and the insect gall midge (GM) (Orseolia oryzae) are two major constraints of rice production. The present study was carried out to improve RPHR-1005, a stable restorer line of the fine-grain-type rice hybrid DRRH-3, for BB and GM resistance through marker-assisted backcross breeding (MABB). Two major GM resistance genes, Gm4 and Gm8, and a major BB resistance gene, Xa21, were selected as target genes for transfer to RPHR-1005. Two sets of backcrosses were carried out to combine either Xa21 + Gm4 or Xa21+ Gm8 into RPHR-1005 using breeding lines in the genetic background of ISM possessing either Gm4 or Gm8 along with Xa21. Foreground selection was performed for Xa21, Gm4, Gm8, and the major fertility restorer genes Rf3 and Rf4 using gene-specific markers, while 61 polymorphic simple sequence repeat (SSR) markers were used for background selection and markerassisted backcrossing was continued until BC2 generation. A promising homozygous backcross-derived plant at the BC2F2 generation possessing Xa21 + Gm4, and another possessing Xa21 + Gm8, were intercrossed to stack the target resistance genes. At ICF4 (inter-crossed F4) , three promising lines possessing the three target resistance genes in a homozygous condition along with fine-grain type, complete fertility restoration, and better panicle exsertion than RPHR-1005 have been identified. Among these, a single line, # RPIC-16-65-125, showed better yield, was highly resistant to BB and GM, was of medium– slender grain type, and had complete fertility restoration along with better panicle exsertion and taller plant type than RPHR-1005. This is the first report of combining resistance against BB and GM in the genetic background of a hybrid rice parental lineDB