Stereochemical inversion of (S)-reticuline by a cytochrome P450 fusion in opium poppy.

The gateway to morphine biosynthesis in opium poppy (Papaver somniferum) is the stereochemical inversion of (S)-reticuline since the enzyme yielding the first committed intermediate salutaridine is specific for (R)-reticuline. A fusion between a cytochrome P450 (CYP) and an aldo-keto reductase (AKR) catalyzes the S-to-R epimerization of reticuline via 1,2-dehydroreticuline. The reticuline epimerase (REPI) fusion was detected in opium poppy and in Papaver bracteatum, which accumulates thebaine. In contrast, orthologs encoding independent CYP and AKR enzymes catalyzing the respective synthesis and reduction of 1,2-dehydroreticuline were isolated from Papaver rhoeas, which does not accumulate morphinan alkaloids. An ancestral relationship between these enzymes is supported by a conservation of introns in the gene fusions and independent orthologs. Suppression of REPI transcripts using virus-induced gene silencing in opium poppy reduced levels of (R)-reticuline and morphinan alkaloids and increased the overall abundance of (S)-reticuline and its O-methylated derivatives. Discovery of REPI completes the isolation of genes responsible for known steps of morphine biosynthesis.

Nanosized solvent superstructures in ultramolecular aqueous dilutions: twenty years' research using water proton NMR relaxation.

BACKGROUND: proton nuclear magnetic resonance (NMR) relaxation times T1, T2, T1/T2 are sensitive to motion and organization of water molecules. Especially, increase in T1/T2 reflects a higher degree of structuring. My purpose was to look at physical changes in water in ultrahigh aqueous dilutions. METHODS: Samples were prepared by iterative centesimal (c) dilution with vigorous agitation, ranging between 3c and 24c (Avogadro limit 12c). Solutes were silica-lactose, histamine, manganese-lactose. Solvents were water, NaCl 0.15 M or LiCl 0.15 M. Solvents underwent strictly similar, simultaneous dilution/agitation, for each level of dilution, as controls. NMR relaxation was studied within 0.02-20 MHz. RESULTS: No changes were observed in controls. Increasing T1 and T1/T2 were found in dilutions, which persisted beyond 9c (manganese-lactose), 10c (histamine) and 12c (silica-lactose). For silica-lactose in LiCl, continuous decrease in T2 with increase in T1/T2 within the 12c-24c range indicated growing structuring of water despite absence of the initial solute. All changes vanished after heating/cooling. These findings were interpreted in terms of nanosized (>4-nm) supramolecular structures involving water, nanobubbles and ions, if any. Additional study of low dilutions of silica-lactose revealed increased T2 and decreased T1/T2 compared to solvent, within the 10(-3)-10(-6) range, reflecting transient solvent destructuring. This could explain findings at high dilution. CONCLUSION: Proton NMR relaxation demonstrated modifications of the solvent throughout the low to ultramolecular range of dilution. The findings suggested the existence of superstructures that originate stereospecifically around the solute after an initial destructuring of the solvent, developing more upon dilution and persisting beyond 12c.

Isopathic versus enantiomeric inhibition of U-50488 HCl toxicity--experimental studies.

BACKGROUND: Previous studies have investigated toxicity inhibition of optically active compounds by potentized preparations of their enantiomers. It was hypothesised that inhibition of toxicity may be stereospecific. This paper presents 2 studies investigating stereoisomer potencies in terms of their ability to counteract toxicity of the (-) stereoisomer. The stereoisomers used were (-)-trans-(1S,2S)-U-50488 HCl and (+)-trans-(1R,2R)-U-50488 HCl. MATERIALS & METHODS: Designs were prospective, blind, randomised, intention-to-treat and compared the efficacy of 2 indistinguishable treatments. The outcome was the difference in survival. Potency 'chords' consisting of 4th, 12th and 30th approximately centesimal dilutions were prepared, representing concentrations of 1.08 x 10(-10) M. One study compared inhibition of (-)-U-50488 toxicity injected ip at the estimated LD50 into male ICR mice, treated with a potency chord of the same stereoisomer, with control ('isopathic' study). The other study compared inhibition of toxicity by potency chords made from the stereoisomers (+)-U-50488 and (-)-U-50488 ('enantiomer' study), Treatments were administered orally on 11 occasions: twice before and nine times after ip injections. RESULTS: The isopathic study did not yield a significant result. In the enantiomer study, comparison of isopathy with enantiomer potency treatment showed a highly significant difference odds ratio 1.97 (95% CI: 1.23-3.14). CONCLUSION: We conclude that enantiomeric potencies are superior to identically produced isopathic potencies, in inhibiting toxicity of (-)-U-50488 HCl. Homeopathic inhibition of toxicity may be stereospecific.

Synthesis, stereochemical analysis, and neuromuscular blocking activity of oximino ether derivatives of progesterone.

This study consists of the synthesis, separation, and stereochemical analysis of oximino ethers, followed by a preliminary pharmacological evaluation for neuromuscular blockade. Synthesis of the compounds began with the double oximation of progesterone, which yielded EE and ZE dioximes as major products. Both stereoisomers were separated and purified by chromatography followed by crystallization. The diether of each dioxime was prepared by O-alkylation with 2-dimethylaminoethyl chloride hydrochloride, using a mixture of potassium tert-butoxide and sodium hydride as base. The diethers were separated from the monoethers by vacuum chromatography. Configurational assignments of all compounds were based on 1HNMR and 13CNMR spectroscopy. Quaternization with methyl bromide yielded the salts which were purified via fractional crystallization. A preliminary pharmacological evaluation was conducted by using mice on a treadmill apparatus. Structure-activity relationships are discussed on the basis of similarities to succinylcholine.

Inhibition of (-)-propranolol hydrochloride by its enantiomer in white mice.

BACKGROUND: This study is based on the hypothesis, that the toxic or physiological effects of an optical isomer may be counteracted or reversed by the administration of a potentized preparation of one of its stereoisomers. In the present study the enantiomer was used. METHODS: 154 ICR conventional mice were used. 77 mice were administered (R)-(+)-propranolol HCl homeopathic potency prior to and during the experiment, and the other 77 were administered indistinguishable placebo. On the day of the experiment the mice were sedated with intraperitoneal Rometar. Once sedated they were injected intraperitoneally with the LD50 dose of (S)-(-)-propranolol HCl. RESULTS: The end point for statistical analysis was the difference in survival between the placebo and treatment mice. The odds ratio for survival of treatment mice relative to placebo mice was 1.64. The hypothesis of equal survival proportions gave a chi-square of 2.0916 (1 degree of freedom), which has a p-value of 0.1481. The analysis was then adjusted for mouse weight and intraperitoneal (-)-propranolol dosage using a logistic regression (LR) model. The LR treatment odds ratio was 2.017 and the LR treatment chi-square was 2.8864 (1 degree of freedom), which has a p-value of 0.0893. Consequently we accept the null hypothesis of no treatment effect on survival. The odds ratio estimates show that the treatment mice are 2.02 times more likely to survive than placebo mice, but this was not statistically significant with p = 0.089. Nine percent more treatment mice survived than placebo mice. The investigators accustomed to handling rodents noted that mouse recovery seemed substantially faster in the treatment mice than in the placebo mice.

Inhibition of (-)-trans-(1S,2S)-U50488 hydrochloride by its enantiomer in white mice -- a placebo-controlled, randomized study.

BACKGROUND: Previous studies have been performed to see if toxicity of optically active compounds may be inhibited by potentized preparations of their enantiomers. The present study is based on the hypothesis that the toxic effects of an optical isomer may be counteracted or reversed by the administration of a potentized preparation of one of its stereoisomers and in particular the enantiomer (patent applied for). METHODS: The design was prospective, blind, randomized, and placebo-controlled. 210 ICR conventional mice were used. 105 mice were administered a mixture of (+)-U50488 hydrochloride homeopathic potencies prior to and during the experiment, and the other 105 were administered indistinguishable placebo. The first 52 mice were used to establish an LD(50) of intraperitoneally administered (-)-U50488 hydrochloride under the conditions of this experiment. The estimated LD(50) was 25 mg/kg. The remaining 158 mice were then administered this LD(50) of (-)-U50488 HCl intraperitoneally. One mouse from the placebo group was excluded from the analysis because it died immediately after the possibly intravenous injection of (-)-U50488 HCl. RESULTS: 67% of homeopathy mice survived compared with 47% of placebo mice. The end point for statistical analysis was the difference in survival between the placebo and homeopathy mice. The analysis was adjusted for mouse weight using a logistic regression (LR) model. The LR treatment odds ratio for survival of treatment mice relative to placebo mice was 2.301 and the LR treatment chi-square was 6.2030 (1 degree of freedom), which has a p-value of 0.0128. Consequently, we reject the null hypothesis of no treatment effect on survival. CONCLUSION: We conclude that toxicity of intraperitoneal injection of (-)-U50488 hydrochloride may be inhibited by administration of a mixture of potencies of its enantiomer.

Inhibition of (-)-propranolol hydrochloride by its enantiomer in white mice--a placebo-controlled randomized study.

BACKGROUND: A previous pilot study was performed to see if toxicity of (S)-(-)-propranolol hydrochloride may be inhibited by a potentized preparation of its enantiomer. The present study is based on the hypothesis that the toxic effects of an optical isomer, may be counteracted or reversed by the administration of a potentized preparation of one of its stereoisomers, and in particular the enantiomer. METHODS: 508 ICR conventional mice were used. 254 mice were administered (R)-(+)-propranolol HCl homeopathic potency prior to and during the experiment, and the other 254 were administered indistinguishable placebo. On the day of the experiment mice were anesthetized with intraperitoneal Rometar. Once sedated the mice were administered the LD50 dose of (-)-propranolol HCl intraperitoneally. RESULTS: The end point for statistical analysis was the difference in survival between the placebo and treatment mice. The odds ratio for survival of treatment mice relative to placebo mice was 1.52. The hypothesis of equal survival proportions gave a chi-square of 5.0429 (1 degree of freedom), which has a p-value of 0.0247. The analysis was then adjusted for mouse weight and intraperitoneal (-)-propranolol dosage using a logistic regression (LR) model. The LR treatment odds ratio was 1.51 and the LR treatment chi-square was 4.8112 (1 degree of freedom), which has a p-value of 0.0283. Consequently, we reject the null hypothesis of no treatment effect on survival. Eleven percent more treatment mice survived than placebo mice. CONCLUSION: We conclude that the toxicity of intraperitoneal (-)-propranolol HCl, may be counteracted by administration of a potency of its enantiomer, in ICR conventional mice which have survived preceding intraperitoneal Rometar injection, and pre-dosing with (+)-propranolol HCl homeopathic potency.