Different Chemical Classes (different + chemical_class)

Distribution by Scientific Domains


Selected Abstracts


Recent developments in anti-inflammatory natural products

MEDICINAL RESEARCH REVIEWS, Issue 5 2009
Raju Gautam
Abstract Many of the inflammatory diseases are becoming common in aging society throughout the world. The clinically used anti-inflammatory drugs suffer from the disadvantage of side effects and high cost of treatment (in case of biologics). Alternative to these drugs are traditional medicines and natural products, which offer a great hope in the identification of bioactive lead compounds and their development into drugs for treating inflammatory diseases. Since ancient times traditional medicines and phytopharmaceuticals are being used for the treatment of inflammatory and other disorders. The present review article describes anti-inflammatory natural products derived from plants and marine sources reported during last decade. The compounds described belong to different chemical classes such as alkaloids, steroids, terpenoids, polyphenolics, phenylpropanoids, fatty acids and lipids, and various miscellaneous compounds. The attempt is also being made to enumerate the possible leads, e.g. curcumin, resveratrol, baicalein, boswellic acid, betulinic acid, ursolic acid, and oleanolic acid, for further development with the help of structure,activity relationship (SAR) studies and their current status. In addition SAR studies carried out on the anti-inflammatory activity of flavonoid compounds and clinical studies performed on anti-inflammatory natural products are also discussed. © 2009 Wiley Periodicals, Inc. Med Res Rev, 29, No. 5, 767,820, 2009 [source]


Nematicidal activity of anion transport blockers against Meloidogyne incognita, Caenorhabditis elegans and Heterorhabditis bacteriophora

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 6 2008
Dhana Raj Boina
Abstract BACKGROUND: Because methyl bromide has been phased out as a soil sterilant, new nematicides are urgently needed. Four different chemical classes of organic acids acting as anion transport (AT) blockers were tested against a free-living nematode, Caenorhabditis elegans Maupas, a plant-parasitic nematode, Meloidogyne incognita (Kofoid and White) Chitwood, and an entomopathogenic nematode, Heterorhabditis bacteriophora Poinar, in toxicity bioassays. The materials tested were DIDS (4,4,-diisothiocyanatostilbene-2,2,-disulfonic acid), 9-AC (anthracene-9-carboxylic acid), NPPB [5-nitro-2-(3-phenylpropylamino)benzoic acid] and IAA-94 (indanyloxyacetic acid). RESULTS: All the compounds showed slowly developing nematicidal activity against second-stage juveniles of M. incognita and adults of C. elegans, but not against H. bacteriophora infective-stage juveniles. The LC50 values of these compounds were < 50 mg L,1 after 48 and 72 h incubation, while at 168 h incubation the LC50 values were < 10 mg L,1 for both sensitive species. Across both species and time, the LC50 values generally differed no more than twofold among the four compounds tested in this study. In contrast, none of the compounds (200 mg L,1) caused more than control mortality to H. bacteriophora, even after 168 h of incubation. CONCLUSION: These compounds are potential leads for commercial nematicides. The insensitivity to H. bacteriophora is consistent with the natural exposure of this nematode to DST (3,5-dihydroxy-4-isopropylstilbene), a stilbene produced by its symbiotic bacterium. Based on the known activity of the compounds used in this study, it is suggested that anion transporters form the probable target sites for DIDS, 9-AC, NPPB and IAA-94 in nematodes. Copyright © 2008 Society of Chemical Industry [source]


Cotton whitefly (Bemisia tabaci) resistance to organophosphate and pyrethroid insecticides in Pakistan

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 2 2002
Mushtaq Ahmad
Abstract Resistance to three organophosphate and four pyrethroid insecticides was monitored from 1992 to 2000 in field populations of adult whiteflies, Bemisia tabaci, from Pakistan using a leaf-dip method. There was generally a very high resistance to dimethoate and deltamethrin, and a moderate resistance to monocrotophos during 1992 to 1996. From 1997 to 2000, resistance to these insecticides dropped to low levels because of less reliance on them for whitefly control, and introduction of new chemistries with novel modes of action that had no cross-resistance to conventional insecticides. Concurrently, whitefly resistance to acephate, fenpropathrin, lambda-cyhalothrin and bifenthrin mostly remained low. An insecticide resistance management strategy is recommended that particularly emphasizes the rotation of still-effective insecticides from different chemical classes along with the use of novel chemicals and other tactics of integrated pest management. © 2001 Society of Chemical Industry [source]


Structural basis of pheromone binding to mouse major urinary protein (MUP-I)

PROTEIN SCIENCE, Issue 5 2001
David E. Timm
Abstract The mouse major urinary proteins are pheromone-binding proteins that function as carriers of volatile effectors of mouse physiology and behavior. Crystal structures of recombinant mouse major urinary protein-I (MUP-I) complexed with the synthetic pheromones, 2-sec-butyl-4,5-dihydrothiazole and 6-hydroxy-6-methyl-3-heptanone, have been determined at high resolution. The purification of MUP-I from mouse liver and a high-resolution structure of the natural isolate are also reported. These results show the binding of 6-hydroxy-6-methyl-3-heptanone to MUP-I, unambiguously define ligand orientations for two pheromones within the MUP-I binding site, and suggest how different chemical classes of pheromones can be accommodated within the MUP-I ,-barrel. [source]


Proteome analysis of apoptosis signaling by S -trityl- L -cysteine, a potent reversible inhibitor of human mitotic kinesin Eg5

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 2 2008
Frank Kozielski
Abstract Mitotic kinesins represent potential drug targets for anticancer chemotherapy. Inhibitors of different chemical classes have been identified that target human Eg5, a kinesin responsible for the establishment of the bipolar spindle. One potent Eg5 inhibitor is S -trityl- L -cysteine (STLC), which arrests cells in mitosis and exhibits tumor growth inhibition activity. However, the underlying mechanism of STLC action on the molecular level is unknown. Here, cells treated with STLC were blocked in mitosis through activation of the spindle assembly checkpoint as shown by the phosphorylated state of BubR1 and the accumulation of mitosis specific phosphorylation on histone H3 and aurora A kinase. Using live cell imaging, we observed prolonged mitotic arrest and subsequent cell death after incubation of GFP-,-tubulin HeLa cells with STLC. Activated caspase-9 occurred before cleavage of caspase-8 leading to the accumulation of the activated executioner caspase-3 suggesting that STLC induces apoptosis through the intrinsic apoptotic pathway. Proteome analysis following STLC treatment revealed 33 differentially regulated proteins of various cellular processes, 31 of which can be linked to apoptotic cell death. Interestingly, four identified proteins, chromobox protein homolog, RNA-binding Src associated in mitosis 68,kDa protein, stathmin, and translationally controlled tumor protein can be linked to mitotic and apoptotic processes. [source]


Development and validation of a gas chromatography/mass spectrometry metabonomic platform for the global profiling of urinary metabolites

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 19 2008
Kishore K. Pasikanti
This paper presents a simple and reliable gas chromatography/mass spectrometry (GC/MS) method for the metabonomic analysis of human urine samples. The sample preparation involved the depletion of excess urea via treatment with urease and subsequent protein precipitation using ice-cold ethanol. An aliquot of the mixture was separated, dried, trimethylsilyl (TMS)-derivatized and 1.0,µL of the derivatized extract was injected into the GC/MS system via split injection (1:10). Approximately 150 putative metabolites belonging to different chemical classes were identified from the pooled human urine samples. All the identified metabolites were selected to evaluate precision and stability of the GC/MS assay. More than 95% of the metabolites demonstrated good reproducibility, with intra-day and inter-day precision values below 15%. Metabolic profiling of 53 healthy male and female urine samples in combination with pattern recognition techniques was performed to further validate the GC/MS metabolite profiling assay. Principal component analysis (PCA) followed by orthogonal partial least squares analysis (OPLS) revealed differences between urinary metabolite profiles of healthy male and female subjects. This validated GC/MS metabolic profiling method may be further applied to the metabonomic screening of urinary biomarkers in clinical studies. Copyright © 2008 John Wiley & Sons, Ltd. [source]