Leela, N K; Madhavan Pillai, P; Dr. Vijay Nair, G(Regional Research Laboratory (CSIR), July , 2002)
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Abstract:
In the present scenario, there is an increasing demand for natural products in
food industry, pharmaceuticals, cosmetics and agricultural sectors. In this context
phytochemical study to identify newer chemicals has got great relevance.
Phytochemical studies have become more reliable and encouraging with the
development of modern analytical techniques.In the present work the leaves of Piper colubrinum (Piperaceae), aerial parts
of Mussaenda fiondosa (Rubiaceae) and Humboldtia vahliana (Leguminosae) and
the pericarp of fruits of Artocarpus heterophyllus (Moraceae) were investigated for
their secondary metabolites. The major compounds isolated belong to the groups of
flavonoids and triterpenoids.Naturally occurring flavonoids have been used widely in chemotaxonomic
studies of plants. Flavones and flavonols constitute a group of biosynthetically
related natural products. No universal function has been established for flavones
and flavonols in plants. However, many functions in individual plants have been
demonstrated. These include protection of plants from ultraviolet light, insects and
pests; pollinator attractants; antioxidants; plant hormone controllers; enzyme
inhibitors and allelopathic agents. Flavonoids are attracting the attention of medical
scientists in recent years because of their anticarcinogenic, antiallergic and antiinflammatory
properties. The recent discovery that flavonoids are involved in the
process of nitrogen fixation in plants also opens the way for agricultural application
of these constituents.Triterpenoids are another class of compounds that are ubiquitous in plants.
Some triterpenoids present in the latex and resins of plants are believed to be
involved in chemical defence against pathogens and herbivores. Triterpenoids
possess various biological properties including anti-inflammatory, antifeedant,
pesticidal, fungitoxic and antimicrobial activities. Triterpenoids with cytotoxic
activity and inhibitory effect on seed germination are also known.
Christudhas, Williams B; Dr.Chandrasekaran,M(Cochin University of Science and Technology, August 9, 1999)
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Abstract:
There is no baseline data available at present on the nature of various
diseases that occur in a orchid population, under cultivation, in any commercial
orchid farm maintained by small scale entrepreneurs who invest considerable amount of money, effort and time. The available data on type of disease symptoms, causative agent, , nature of pathogens, as to bacteria or ftmgi or any other biological agents, and their source, appropriate and effective control measures could not be devised, for large scale implementation and effective management, although arbitrary methods are being practiced by very few farms. Further influence of seasonal variations and environmental factors on disease outbreak is also not scientifically documented and statistically verified as to their authenticity.
In this context, the primary objective of the present study was to create a data
bank on the following aspects
1. Occurrence of different disease symptoms in Dendrobium hybrid over a period of one year covering all seasons
2. Variations in the environmental parameters at the orchid farms
3. Variations in the characteristics of water used for irrigation in the selected orchid farm
4. Microbial population associated with the various disease symptoms
5. Isolation and identification of bacteria isolated from diseased plants
6. Statistical treatment of the quantitative data and evolving statistical model
Description:
Department of Biotechnology, Cochin
University of Science and Technology
Maya,K; Seralathan,P(Dept. of Marine Geology and Geophysics,Faculty of Science, March , 2005)
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Abstract:
The present study is an attempt to address issues related to sediment properties like texture, mineralogy and geochemistry as well as water quality of two important rivers of central Kerala-the Periyar and the Chalakudy rivers. The main objectives of the study are to investigate the textural and mineralogical characteristics as well as transportation and depositional mechanisms of the sediments of Periyar and Chalakudy rivers, to find out the geochemical variability of organic carbon, phosphorus and certain major (Na,K,Ca and Mg) and minor/trace(Mn,Pb,Ni,Cr, and Zn) elements in the bulk sediments and mud fraction of these rivers, to evaluate the status of heavy metal pollution registered in the sediments of these rivers, to assess the physico-chemical characteristics and water quality of Periyar and Chalakudy rivers and to estimate the dissolved nutrient flux through the Periyar and Chalakudy rivers into the receiving coastal waters.
The granulometric characteristics as well as statistical parameters of the sediments of Periyar and Chalakudy rivers depend on the flow pattern controlled by the gradient of the terrain. Compared to Periyar, fluctuations in the dispersal of particles are more in Chalakudy river. In Periyar river, the P and Fe in bulk sediments show a positive correlation with C-org, while in Chalakudy river, both the elements are related to THM concentration. In general, C-org, Fe and P Shows an increasing trend downstream. In Periyar river, the P and Fe in bulk sediments show a positive correlation with C-org, while in Chalakudy river, both the elements are related to THM concentration. Among these two rivers, the pollution of water is several fold higher in Periyar river due to influx due to influx of considerable quantity of liquid and solid wastes of industrial/domestic/urban origin. Nutrient analysis reveals 2-3 times increase in N and P during monsoon season whereas SiO2-Si shows a decreasing trend.
Kala, K; Dr. N. Manoj(Cochin University of Science and Technology, July 3, 2016)
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Abstract:
Organic molecules with π-conjugated scaffolds end-capped with electron donor and acceptor groups are widely investigated due to their immense application potentials and hence belong to a promising area of organic chemistry. Donor-acceptor materials have found wide variety of applications such as dyes in dye-sensitised solar cells (DSSCs), organic photovoltaics, organic light emitting diodes, nonlinear optical devices, chemosensors, diagnostic probes and as therapeutic agents. Despite their use in such a wide range of applications, many fundamental properties of donor acceptor materials are still poorly understood. Even simple structural modifications can bring unexpected electronic and photophysical properties and wider understanding of the interaction between donor and acceptor is thus required. Furthermore, many such systems show diversity in properties in solution state or in their condensed state such as crystalline or amorphous forms. For example, some of these molecules show aggregation induced quenching or enhancement in emission in the solid state. Thus, structural motifs that facilitate intermolecular interaction via hydrophobic association, hydrogen bonding or electrostatic effects can lead to excellent control over their supramolecular functions. Some of the important structural types which used as donors are triarylamines, carbazoles, phenothiazine, fluorenes, thiophenes, and oligothiophenes. Strongly electron withdrawing groups or electron deficient heterocyclic systems such as oxadiazoles, diarylborons, quinolines, quinoxalines, thienopyrazines, and benzothiadiazoles, cyanoacetic acid, rhodanine-3-acetic acid, barbituric acid, and thiobarbituric acid etc., have been used as the acceptors in the
design of donor-acceptor systems.
Rekha R mallia; Dr.Prathapan, S(Cochin University of Science and Technology, December , 2007)
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Abstract:
The thesis entitled ‘Studies on the Solvent Dependence in the
Reaction of a Few (Anthracen-9-yl)methylamines and Sulfanes with
Reactive Acetylenes’ is divided into six chapters. ln Chapter l a general
survey of electron transfer reactions, Diels-Alder reactions and Michael-type
additions is presented. A detailed discussion on the synthesis of several
(anthracen-9-yl)methylamines is presented in Chapter 2. In Chapter 3,
results of preliminary photophysical studies on a few (anthracen-9yl)
methylamines are compiled. A detailed discussion on extensive
examination of dependence in the reaction of (anthracen-9-yl)methylamines
with reactive acetylenes is presented Chapter 4. Details on the synthesis and
reaction of a few (anthracen-9-yl)methylsulfanes with DMAD are described in
Chapter 5.
Malini, K A; Dr.Anantharaman, M R(Cochin University of Science and Technology, May 30, 2001)
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Abstract:
This thesis mainly deals with the preparation and studies on magnetic composites based on spinel ferrites prepared both chemically and mechanically. Rubber ferrite composites (RFC) are chosen because of their mouldability and flexibility and the ease with which the dielectric and magnetic properties can be manipulated to make them as useful devices. Natural rubber is chosen as the
Matrix because of its local availability and possible value addition. Moreover, NR represents a typical unsaturated nonpolar matrix. The work can be thought of as two parts. Part l concentrates on the preparation and characterization of nanocomposites based on y-Fe203. Part 2 deals with the preparation and characterization of RFCs containing Nickel zinc ferrit In the present study magnetic nanocomposites have been prepared by ionexchange method and the preparation conditions have been optimized. The insitu incorporation of the magnetic component is carried out chemically. This method is selected as it is the easiest and simplest method for preparation of nanocomposite. Nanocomposite samples thus prepared were studied using VSM, Mossbauer spectroscopy, Iron content estimation, and ESR spectroscopy. For the preparation of RFCs, the filler material namely nickel zinc ferrite having the general formula Ni)_xZnxFez04, where x varies from 0 to 1 in steps of 0.2 have been prepared by the conventional ceramic techniques. The system of Nil_xZn"Fe204 is chosen because of their excellent high frequency characteristics. After characterization they are incorporated into the polymer matrix of natural rubber by mechanical method. The incorporation is done according to a specific recipe and for various Loadings of magnetic fillers and also for all compositions. The cure characteristics, magnetic properties and dielectric properties of these composites are evaluated. The ac electrical conductivity of both ceramic nickel zinc ferrites and rubber ferrite composites are also calculated using a simple relation. The results are correlated.
Description:
Physics Department,
Cochin UniversIty of Science & Technology
Annam,Chacko P; Dr.Madhavan Pillai, P(Cochin University of Science and Technology, May , 1987)
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Abstract:
Strychnine, the major alkaloid present in Strychnos nuxvomica seeds has been reported to stimulate the entire central nervous system with preference for the spinal cord. It is a powerful convulsant and because of this property, it is an important pharmacological tool as it plays a unique role as an inhibitor of post synaptic inhibitory impulses. It is useful to study inhibitory
transmitter and receptor types. However, because of its extreme toxicity, strychnine does not have any therapeutic application in the Western system of medicine. The present work was undertaken with a view to obtaining strychnine derivatives having CNS stimulating properties but with sufficiently low toxicity so that they may eventually find some application in medicine. As strychnine is isolated from the locally available strychnos Nugvomica seeds, it’s possible utilization in therapeutics will have considerable commercial significance. This work tries to provide several new compounds which are significantly less toxic than strychnine and its N—oxide as shown from the pharmacological Studio As they also possessed CNS stimulating properties, they are well suited for further screening to assess their potential as valuable therapeutic agents.
Description:
Department of Applied Chemistry, Cochin University
of Science and Technology
Vidya,Raman; Prathapan,S(Department of Applied Chemistry ,Faculty of Science, 2004)
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Abstract:
The thesis entitled studies on the synthesis and transformations of a few 2(3H)- and 3(2H)- furanones. Furanones represent an interesting class of heterocyclic compounds, which constitute the central ring system of many natural products. The derivatives of furan is divided, depending on their structure 2(3H)-furanones(I), 2(5H)-furanones(II), and 3(2H)-furanones(III). Systems I&II are unsatured gama lactones known as ‘butenolides’. Compounds of this type also known as ‘crotonolactones’ based on the parent crotonic acid. In conclusion a number of 2(3H)-and 3(2H)- furanones were synthesized from dibenzoylalkene precursors and were characterized on the basis of spectral analytical and X-ray data. On direct irradiation 3,3-bis(4-chloropheneyl)-5-aryl-3H-furan -2-ones underwent decarbonylation to yield the corresponding alpha, beta- unsaturated carbonyl compounds and upon sensitized irradiation they underwent dimersation arising through a 2+2 cycloaddition reaction. Our studies on 3(2H)-furanones revealed that these compounds are thermally stable, while they undergo extensive decomposition to intractable mixtures under the influence of light. Similarly, the novel dibenzoylalkenes- type systems containing hetroatomatic rings synthesized by us also underwent extensive decomposition under the influence of heat. Some of the 3(2H)-furanones synthesized by us exhibit remarkable anti-proliferative activity.
Jean John, Vadakkan; Dr.Prathapan, S(Cochin University of Science & Technology, September , 2002)
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Abstract:
In this thesis, we report our endeavours in the synthesis of a few polycyclic compounds. We were interested in the synthesis of a few bicyclic compounds designed to undergo interesting photochemical transformations including tripletmediated di-π-methane rearrangement and/or competing singlet-mediated electrocyclic reactions. Our target molecules have "inbuilt" structural features which will potentially alter the photochemistry of the substrate under consideration.The present investigation was undertaken to test our hypothesis on selective intramolecular quenching of singlet or triplet excited states of molecules.We adopted Dies-Alder reaction for the synthesis of several of the bicyclic compounds we were interested in. Some of the precursor dienes synthesised by us are capable of undergoing intramolecular cycloaddition reactions as well. So, it was important to delineate the conditions and structural features that will enable a particular molecule to undergo intermolecular and intramolecular Dies-Alder reaction when treated with a suitable dienophile.Though, the main focus of this thesis is on the synthesis of bicyclic and tricyclic systems capable of undergoing di-π-methane rearrangement, in the last chapter of this thesis, we describe our findings on the synthesis of a few dispirocompounds. These systems were encountered as unexpected products in the attempted synthesis of novel dibenzoylalkene-type systems. Consequently, a brief survey on the synthesis and transformations of dibenzoylalkenes is also included as an integral part of this thesis.
Description:
Department of Applied Chemistry, Cochin University of Science and Technology