Disease relevance of AIDS160500

• PURPOSE: Our purpose was to compare, on a pharmacokinetic, biological, and clinical basis, the racemic mixture d,l-FA with the pure l-FA in rescue of high-dose MTX therapy (5 g/m2) in children with acute lymphocytic leukemia (ALL) [1].
• The (+) and (-) isomers of the above racemic mixture did not differ significantly in their capacity to inhibit phage replication [2].
• It is administered clinically as a racemic mixture, but only one enantiomer is active (eutomer) while the other (distomer) has been implicated in causing toxicity [3].
• The subsequently determined crystal structure with HIV-1 protease, cocrystallized from a racemic mixture, exclusively reveals the S,R,S-enantiomer accommodated to the binding pocket [4].
• Beginning with a cocrystal structure of a Phe-Pro peptidomimetic bound to the HIV Pr, design was initiated that resulted in the substituted 2-butanol compound 8 as the lead compound (Ki = 24.5 microM, racemic mixture) [5].

Psychiatry related information on AIDS160500

• Even though the apparent anaesthetic state produced in these healthy volunteers did not differ qualitatively between the three drug groups, recovery times (assessed using a standardized battery of psychometric tests) were consistently shorter following the individual isomers compared with the racemic mixture [6].

High impact information on AIDS160500

• Here we report scanning tunnelling microscopy studies of cysteine adsorbed to a (110) gold surface, which show that molecular pairs formed from a racemic mixture of this naturally occurring amino acid are exclusively homochiral, and that their binding to the gold surface is associated with local surface restructuring [7].
• 4-Hydroxy-2-nonenal (HNE), a racemic mixture of 4R- and 4S-enantiomers, is a major product of lipid peroxidation and is believed to be largely responsible for the cytopathological effects observed during oxidative stress [8].
• We studied the cardiac effects of i.v. administration of each isomer and the racemic mixture (dl-) in six normal males by digitized echocardiography, systolic time intervals and ECG [9].
• Nevertheless, our results suggest that the racemic mixture of AP5 should not be used as an NMDA antagonist in retinal research, due to the AP4-like actions of its L-enantiomer [10].
• Dose-dependent insulin-releasing activities at 3.3 and 16.7 mM glucose levels were determined for the racemic mixture containing all four stereoisomers [11].

Chemical compound and disease context of AIDS160500

• Racivir [RCV; (+/-)-beta-2',3'-dideoxy-5-fluoro-3'-thiacytidine], a 50:50 racemic mixture of the two beta nucleoside enantiomers, is currently in development for the treatment of human immunodeficiency virus type 1 (HIV-1) infections [12].
• Lactobacillus sp. strain 173 produced a racemic mixture of D- and L-lactic acid at pH 6.3, whereas the proportion of L-lactic acid was higher than that of D-lactic acid at pH 5 [13].
• We previously reported that the racemic mixture and both enantiomers of gossypol inhibit the replication of human immunodeficiency virus-type 1 (HIV-1) (Lin et al., Antimicrob Agents Chemother 33: 2149-2151, 1989) [14].
• Propranolol is a nonselective beta-adrenergic blocker used as a racemic mixture in the treatment of hypertension, cardiac arrhythmias, and angina pectoris [15].
• Both clenbuterol enantiomers produced significant increases in skeletal muscle mass, while being less active in producing cardiac ventricular muscle hypertrophy than the racemic mixture [16].

Biological context of AIDS160500

• The results of analysis of the product mixture derived from autoxidation of optically pure Ch-15-HpETE by atmospheric pressure chemical ionization-mass spectrometry coupled with chiral high performance liquid chromatography indicate that the major isoprostane diastereomers are formed as a racemic mixture [17].
• Substituting a racemic mixture of the beta-amino acid isoserine for serine in a related peptide ligand (SFLLRN) produced an active peptide ((iso-S)FLLRN) that is approximately 15-20% as potent as SFLLRN as judged by platelet aggregation [18].
• The experimental observation that in the racemic mixture, (2S, 5S)-5-fluoromethylornithine is exclusively responsible for the enzyme inhibition can be explained on the basis of the active site topology [19].
• The racemic mixture has an IC50 of 11.2 +/- 0.5 microM, whereas (S)-HA-966 has an IC50 greater than 900 microM [20].
• Hybrid silicas with hollow tubular morphologies were obtained by the hydrolysis of the enantiomerically pure compounds, (R,R)-1 or (S,S)-1, whereas the corresponding racemic mixture, rac-1, led to a hybrid with ball-like structures [21].

Anatomical context of AIDS160500

• In one series of experiments, PAF was applied focally to single, isolated osteoclasts (1 nM to 1 microM racemic mixture, in an application micropipette) [22].
• Embryos of two stages (3-4 and 5-6 somites) were exposed for 24 h to a racemic mixture of D-L B-OHB at levels of 8, 16, or 32 mM/L [23].
• After incubation of a synthetic racemic mixture of 9,10-epoxystearic acid with microsomes of yeast expressing CYP94A1, the chirality of the residual epoxide was shifted to 66:34 in favour of the (9S,10R) enantiomer [24].
• (S)-11a was evaluated as a substrate for P815 tryptophan hydroxylase and determined to have an apparent Km of 4.31 +/- 1.07 mM, essentially half the value previously reported for the racemic mixture of 11a with rat brain stem tryptophan hydroxylase [25].
• The enantiomer more active on HMG-CoA reductase was 70- and 1.6-fold more potent on arterial myocyte proliferation than its antipode and the racemic mixture, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)[26]

Associations of AIDS160500 with other chemical compounds

• Single-crystal X-ray diffraction analysis of a racemic mixture of Ru(Zn2L4)3 showed that three of the six Zn2+-cyclen units are orientated to face the opposite side of the molecule with three apical ligands (Zn2+-bound HO-) of each of the three Zn2+ located on the same face [27].
• Another type of the one-step (S)-isomer biocatalytic preparation from racemic mixture of propranolol is the biodegradation with the fungus [28].
• In epitrochlearis muscles isolated from obese Zucker rats, insulin (2 mU/ml) significantly (p < 0.05) increased in vitro protein synthesis (phenylalanine incorporation into protein) and decreased net protein degradation (tyrosine release), whereas a racemic mixture of ALA (2 mM) had no effect on either process [29].
• The most widely used long-acting amide local anaesthetic is bupivacaine, a racemic mixture of 2 stereoisomers [30].
• This paper describes the labeling of the highly potent serotonin (5-HT) uptake blocker, McN-5652-Z (trans-1,2,3,5,6,10 beta-hexahydro-6-[4-(methylthio)phenyl]pyrrolo-[2,1-a]-isoquinoline; racemic mixture), with 11C and the evaluation of this radiotracer in rodents with respect to its in vivo binding characteristics [31].

Gene context of AIDS160500

• S-fluoxetine is on average a 5 fold weaker CYP2C9 inhibitor than either R-fluoxetine or the racemic mixture [32].
• The Ser-->Phe substitution indeed affected the potency and P-gp isoform specificity of some of the modulators, in particular that of CP117227 (racemic mixture and enantiomers), which were active against wild-type but not mutant mdr3 [33].
• The two enantiomers of the racemic mixture MEPQ inhibited AChE at similar rates [34].
• 1. We investigated the effects of the non-peptide NK1 receptor antagonist, CP-96,345, its inactive enantiomer CP-96,344, and the racemic mixture (+/-)-CP-96,345, on the binding of [3H]-nimodipine and [3H]-diltiazem to L-type calcium channels in rat cerebral cortex membranes [35].
• The new analogues comprise the four possible stereoisomers of 1-amino-1-carboxycyclopentane-3-acetic acid (1,3-homo-ACPD) and the racemic mixture of (1RS,2RS)-1-amino-1-carboxycyclopentane-2-acetic acid (1RS,2RS-homo-ACPD), (1RS,2RS)-Homo-ACPD was shown to be a competitive mGlu2 receptor antagonist with a KB of 391 microM [36].

Analytical, diagnostic and therapeutic context of AIDS160500

• This species was shown by x-ray crystallography to be a racemic mixture of P-P and M-M helices [37].
• Although used clinically as a racemic mixture, S(-)-bupivacaine appears less toxic than the R(+)-enantiomer despite at least equal potency for local anesthesia [38].
• DESIGN: In this randomized, placebo-controlled, double-blind study, 160 women received 400 microg FA, the equimolar amount of MTHF (480 microg, racemic mixture), or a placebo daily during an 8-wk treatment period [39].
• In previous studies, a racemic mixture of (R)-[(11)C]verapamil and (S)-[(11)C]verapamil has been used as tracer for assessing P-gp function using positron emission tomography (PET) [40].
• The racemic mixture was resolved on a chiral HPLC column to obtain pure samples of (-)-6-[18F]FNE and (+)6-[18F]FNE [41].

References