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1.
Nat Prod Res ; 35(4): 600-606, 2021 Feb.
Article in English | MEDLINE | ID: mdl-30931616

ABSTRACT

Falcatane A (1) and B (2), 4-oxo-3,24-dinor-2,4-secooleanane- and 3-oxo-24- noroleanane-type triterpenoids, together with seven known triterpenoids involving 2-hydroxy-3-oxo-24-noroleana-1,4,12-trien-28-oic acid (3) and oleanolic acid (4), were separated from the ethyl acetate roots extract of Dolichos trilobus using the column chromatography of silica gel, MCI gel, and Sephadex LH-20. The compounds were determined by analysis of IR, NMR spectroscopic data and mass spectrometry. In the bioassay, all isolates showed varying degree of the α-glucosidase inhibitory activity except compound 2.


Subject(s)
Dolichos/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Triterpenes/isolation & purification , Triterpenes/pharmacology , Dolichos/drug effects , Glycoside Hydrolase Inhibitors/chemistry , Magnetic Resonance Spectroscopy , Mass Spectrometry , Plant Roots/chemistry , Spectrophotometry, Infrared , Triterpenes/chemistry
2.
Biochem J ; 395(3): 629-39, 2006 May 01.
Article in English | MEDLINE | ID: mdl-16441240

ABSTRACT

Plant-pathogen interactions play a vital role in developing resistance to pests. Dolichos biflorus (horse gram), a leguminous pulse crop of the subtropics, exhibits amazing defence against attack by pests/pathogens. Investigations to locate the possible source of the indomitable pest resistance of D. biflorus, which is the richest source of LOX (lipoxygenase) activity, have led to a molecule that exhibits LOX-like functions. The LOX-like activity associated with the molecule, identified by its structure and stability to be a tetrameric lectin, was found to be unusual. The evidence for the lectin protein with LOX activity has come from (i) MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS, (ii) N-terminal sequencing, (iii) partial sequencing of the tryptic fragments of the protein, (iv) amino acid composition, and (v) the presence of an Mn2+ ion. A hydrophobic binding site of the tetrameric lectin, along with the presence of an Mn2+ ion, accounts for the observed LOX like activity. This is the first ever report of a protein exhibiting both haemagglutination and LOX-like activity. The two activities are associated with separate loci on the same protein. LOX activity associated with this molecule adds a new dimension to our understanding of lectin functions. This observation has wide implications for the understanding of plant defence mechanisms against pests and the cellular complexity in plant-pathogen interactions that may lead to the design of transgenics with potential to impart pest resistance to other crops.


Subject(s)
Dolichos/enzymology , Lipoxygenase/metabolism , Plant Lectins/metabolism , Seeds/enzymology , Amino Acid Sequence , Antibodies/immunology , Dolichos/drug effects , Enzyme Stability , Lipoxygenase/chemistry , Lipoxygenase/immunology , Lipoxygenase/isolation & purification , Lipoxygenase Inhibitors/pharmacology , Molecular Sequence Data , Plant Lectins/chemistry , Plant Lectins/immunology , Plant Lectins/isolation & purification , Seeds/drug effects , Sequence Alignment , Spectrum Analysis , Substrate Specificity , Temperature
3.
Int J Environ Res Public Health ; 2(2): 219-27, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16705821

ABSTRACT

We investigated the changes in the properties of water when exposed to sunlight for 40 days. We hypothesize and prove that solar irradiation to water entraps electromagnetic radiation as potential energy, which becomes kinetic energy in various systems. It is postulated that photochemically-induced energy transfers, associated with individual spectral emission of visible spectrum of solar light, exert diverse influences on biological systems. Bottles of distilled water, individually wrapped in spectral-colored cellophane were exposed to sunlight and compared to an unwrapped bottle to determine chemical and physical changes as well as modifications of biological properties. Each bottle of water was named according to the color of cellophane paper with letter E (stands for exposed) as a prefix with (E-violet, E-indigo, E-blue, E-green, E-yellow, E-orange, and E-red). E-control (without wrap) was exposed to polychromatic sunlight. This study addresses two main issues viz., the chemical and physical changes in E-water and its effect on biological activities. Chemical and physical composition analysis using inductively coupled plasma atomic emission spectrometry; physical conductance by a Wheatstone Bridge type conductivity meter; osmolarity by a vapor pressure osmometer; and, salt solubility profile of 10% sodium bicarbonate were determined. Furthermore, testing the effect of E-waters on human lymphocyte proliferation, mosquito larvae hatching and seed germination determined the functional role of solar radiation through specific spectrum/s of visible light on various biological processes. We found that water exposed to visible spectral emissions of sunlight had an altered elemental composition, electrical conductance, osmolarity and salt-solubility, as well as differences in bio-modulatory effects. A gradual increase in leaching of Boron from E-violet to E-red was noted. E-indigo showed maximal increase in electrical conductance and maximal salt solubility of sodium bicarbonate. E-blue inhibited phyto-hemagglutinin-induced immune cell proliferation and mosquito larvae hatching. E-orange stimulated root elongation in seed germination. We conclude that 40-day exposure of water to specific solar spectrum changes chemical and physical properties and influences on biological activity.


Subject(s)
Color , Sunlight , Water/chemistry , Water/pharmacology , Animals , Anopheles , Boron/analysis , Cell Proliferation/drug effects , Cells, Cultured , Dolichos/drug effects , Dolichos/growth & development , Germination/drug effects , Humans , Larva/drug effects , Larva/growth & development , Seeds/drug effects , Seeds/growth & development , Sodium Bicarbonate/chemistry , Solubility , T-Lymphocytes/drug effects , T-Lymphocytes/metabolism , Water/analysis
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