(1) Acetaldehyde and acetone were also detected in the irradiated squalene, which may be formed via a 6-methyl-5-hepten-2-one intermediate.
(2) When treated with the carbonyl reagent 2,4-dinitrophenylhydrazine, the reactive fractions yielded derivatives, some of which were identified by mass spectrometry as hydrazones of nonenal, heptenal, pentenal, and crotonaldehyde.
(3) L. leiopenis secretion contains E-4-methyl-4-hepten-3-one(IV), 4-methylheptan-3-one(V), E,E-2,4-dimethylhexa-2,4-dien-1-ol(VII), and E,E-2,4-dimethylhepta-2,4-dien-1-ol(VIII).
(4) NB-598, (E)N-ethyl-N-(6,6-dimethyl-2-hepten-4-ynyl)-3-[(3,3'-bith iophen-5-yl)methoxy]benzene-methanamine, was found to inhibit human microsomal squalene epoxidase (from Hep G2 cells) in a competitive manner.
(5) The effects of varying the structure of philanthotoxin (PhTX) were investigated on binding of the channel blockers: [3H]perhydrohistrionicotoxin (H12-HTX) to the nicotinic acetylcholine receptor (nACh-R) of Torpedo electric organ and [3H]MK-801 [( 3H]-5-methyl-10,11-dihydro-5H-dibenzocyclo-hepten-5,10-imine maleate) to the N-methyl-D-aspartate receptor (NMDA-R) of rat brain cortex.
(6) Application of (+)-5-methyl-10,11-dihydro-5H-dibenzo-[a,d]cyclo-hepten- 5,10-imine hydrogen maleate (MK-801) and 2-amino-5-phosphonopentanoic acid (2-AP5), antagonists of N-methyl-D-aspartate (NMDA) excitatory amino acid (EAA) receptors, reduced the late multiple population spike component in slices from aged rats incubated in 8-CPT.
(7) antagonists such as kynurenic acid, 2-amino-5-phosphonopentanoic acid (AP5), cis-2,3-piperidine dicarboxylic acid (cis-2,3 PDA) and (+)-5-methyl-10,11,-dihydro-5H-dibenzo(a,d)cyclo-hepten-5,10-imine maleate (MK 801), has been studied on the epileptiform activity elicited in rat hippocampal slices, bathed in penicillin (1 mM).
(8) For these investigations 14C-labelled levomenol ((-)-6-methyl-2-(4-methyl-3-cyclohexen-1-yl)-5-hepten-2-ol; (-)-alpha-bisabolol) was prepared by biochemical incorporation of [14C]-acetate into the molecule.
(9) Perhaps 2-tr-heptenal is only produced in the presence of a defined ratio of both isomeric hydroperoxides.
(10) 6-Methyl-5-hepten-2-one can also undergo breakdown to form malonaldehyde.
(11) Six components, whose concentrations were depressed after adrenalectomy, were identified: 2-heptanone, trans-5-hepten-2-one, trans-4-hepten-2-one, n-pentyl acetate, cis-2-penten-1-yl acetate, and 2,5-dimethylpyrazine.
(12) Compounds with high activity and a broad activity spectrum are 2-ethyl-hexen-2al, 2-isopropyl-5-methyl-hexen-2-al and 2-propyl-hepten-2-al, these compounds are specially active against spores and mycobacteria.
(13) From the leaves and flowers of Lippia dulcis collected in Panama, a new sweet sesquiterpene identified as (+)-4 beta-hydroxyhernandulcin [2] was isolated, accompanied by (+)-hernandulcin [1], (-)-epihernandulcin [3] (a novel natural product), and 6-methyl-5-hepten-2-one [4].
(14) Synthesis of 6,6-dimethyl-1-hepten-4-yn-3-ol and 2-alken-4-ynylamines were modified.
(15) cis-2-Methyl-6-methylamino-2-hepten-1-ol was identified as a minor urinary metabolite of isometheptene in the rat.
(16) Four additional new bioactive heptenes, melodorinol [2], homomelodienone [4], 7-hydroxy-6-hydromelodienone [5], and homoisomelodienone [7] have been isolated from Melodorum fruticosum.
(17) The beta-alkyl substituted acrolein congeners crotonaldehyde, trans-2-pentenal, trans-2-hexenal, 2,4-hexadienal, and trans-2-heptenal were clearly mutagenic in a slightly modified preincubation Ames test with Salmonella typhimurium TA100 with and without S9 mix using a threefold bacterial cell density and a 90-min preincubation time, whereas trans-cis-2,6-nonadienal did not show any mutagenic activity.
(18) The origin of 2-tr-heptenal could not be clarified; it occured neither in the experiments with predominating 9-LHPO nor in those with predominating 13-LHPO.
(19) Washing the microsomes after incubation with hexenal or heptenal did not substantially decrease the inhibition, but with nonenal the inhibition was reduced by washing.
(20) As reaction products of thermal treatments among other increased amounts of acetoin, furfural, 5-methylfurfural and 6-methyl-5-hepten-2-one were established.
Isomer
Definition:
(n.) A body or compound which is isomeric with another body or compound; a member of an isomeric series.
Example Sentences:
(1) An unsaturated fatty acid auxotroph of Escherichia coli was grown with a series of cis-octadecenoate isomers in which the location of the double bond varied from positions 3 to 17.
(2) Fluorination with [18F]acetylhypofluorite yields 6-[18F]fluoro-L-dopa with 95% radiochemical purity; fluorination of the same substrate with [18F]F2 yields a mixture of all three structural isomers in a ratio of 70:16:14 for 6-, 5-, and 2-fluoro compounds.
(3) The cis isomer was retained longer in liver, particularly in mitochondria, but had low retention in that portion of the endoplasmic reticulum isolated as the rough membrane fraction.
(4) The purity and configuration of each isomer of the free acid and N-chloroacetylated derivative were ascertained by: (a) paper chromatography in five solvent systems, (b) elemental analysis, (c) Van Slyke nitrous acid determination of alpha-carbonyl carbon, and (d) Van Slyke ninhydrin determination of alpha-carbonyl carbon, and (e) optical rotation.
(5) The stronger negative potentials may weaken electrostatic receptor interactions and, thereby, cause the trans(E)-isomers to be less active than cis(Z)-isomers.
(6) The identity of each of the three forms was determined by carboxymethylation of the free cysteines in each isomer with [3H]iodoacetic acid followed by determination of the labelled cysteines by tryptic peptide mapping.
(7) In contrast to the enantiomeric discrimination observed with racemic amine, the individual isomers were metabolized at approximately the same rate.
(8) To further assess different binding behavior of these two isomers, association rate was measured.
(9) None of the 3 beta- or 5 beta-isomers had any effect.
(10) Isomers and epimers of glucose influence insulin and cAMP in a parallel fashion as do sulfonylurea compounds (tolbutamide and glibenclamide).
(11) Bioaccumulation experiments were performed on the hexachlorocyclohexane isomers alpha-HCH, beta-HCH, gamma-HCH and delta-HCH, testing them simultaneously.
(12) Although serum total LDH activity was not altered, the LD5 isoenzyme was proportionately higher in the HCH isomers treated animals.
(13) Racemic verapamil and the L- and D-isomer increased cellular vincristine accumulation to the same extent.
(14) The hypothesis that opiate agonism requires an N substituent in the axial position does not appear to be consistent with the increased potency of beta isomers in which axial N substituents are thermodynamically more unstable.
(15) In the case of adducts with the diol-epoxides of benzo[c]phenanthrene, the energetically most favored structures are isomers with significant biological activity.
(16) Liver regeneration was stimulated in male rats with two-thirds of the liver removed by feeding a basal diet supplemented with acetaminophen (0.35-1.5%; weight basis), 2-acetamidophenol (1.0%) and acetophenetidin (1.0%) over a period of 10 days po, but was in the control range with the m-isomer, 3-acetamidophenol (1.0%), N-butyryl-p-aminophenol (1.0%), o-, m- and p-aminophenols (0.50%) and 4-acetamidothiophenol.
(17) However, exposure of the cells to either of the two isomers of azoxy-procarbazine led to significant DNA damage and cytotoxicity.
(18) 1"-Oxobufuralol (3) was reduced with a complex of (2S)-(-)-2-amino-3-methyl-1,1-diphenylbutan-1-ol and borane, yielding 2, which had a 95:5 ratio of the possible 1"R and 1"S isomers as determined by HPLC.
(19) As the two signals had the same intensities, it was suggested that equivalent amounts of cis and trans isomers of the alkenylmether were formed.
(20) The most important recent work has concerned the different anticoagulant potencies and metabolic pathways of the optical isomers of some of these drugs.