Racemization of oxazepam and chiral 1,4-benzodiazepines. DFT study of the reaction mechanism in aqueous solution

Cannabinoid-Induced Stereoselective Inhibition of R-S-Oxazepam Glucuronidation: Cannabinoid-Oxazepam Drug Interactions

Benzodiazepines (BZDs) such as oxazepam are commonly prescribed depressant drugs known for their anxiolytic, hypnotic, muscle relaxant, and anticonvulsant effects and are frequently used in conjunction with other illicit drugs including cannabis. Oxazepam is metabolized in an enantiomeric-specific manner by glucuronidation, with S-oxazepam metabolized primarily by UGT2B15 and R-oxazepam glucuronidation mediated by both UGT 1A9 and 2B7. The goal of the present study was to evaluate the potential inhibitory effects of major cannabinoids, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), and major THC metabolites, 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (11-COOH-THC), on the UGT-mediated metabolism of R- and S-oxazepam. The cannabinoids and metabolites were screened as inhibitors of R- and S-oxazepam glucuronidation in microsomes isolated from HEK293 cells overexpressing individual UGT enzymes (rUGTs). The IC50 values were determined in human liver microsomes (HLM), human kidney microsomes (HKM), and rUGTs and utilized to estimate the nonspecific, binding-corrected Ki (Ki,u) values and predict the area under the concentration-time curve ratio (AUCR). The estimated Ki,u values observed in HLM for S- and R-oxazepam glucuronidation by CBD, 11-OH-THC, and THC were in the micromolar range (0.82 to 3.7 µM), with the Ki,u values observed for R-oxazepam glucuronidation approximately 2- to 5-fold lower as compared to those observed for S-oxazepam glucuronidation. The mechanistic static modeling predicted a potential clinically significant interaction between oral THC and CBD with oxazepam, with the AUCR values ranging from 1.25 to 3.45. These data suggest a pharmacokinetic drug-drug interaction when major cannabinoids like CBD or THC and oxazepam are concurrently administered.

Theoretical study of interaction between temozolomide anticancer drug and hydroxyethyl carboxymethyl cellulose nanocarriers for targeted drug delivery by DFT quantum mechanical calculation

In this article for the first time the quantum calculations of 3-methyl-4-oxoimidazo[5,1-d][1,2,3,5]tetrazine-8-carboxamide (Temozolomide) in HCM-Cellulose Substrate are evaluated using the B3LYP/6-31G level of theory. The non-bonded interaction effects of the molecule Temozolomide, HCM-Cellulose on the electronic properties, chemical shift tensors and natural charge have also been detected. Natural bond orbital analysis (NBO) suggests that Temozolomide as an electron donor and HCM-Cellulose acted as an electron acceptor in the Temozolomide/HCM-Cellulose complex. The electronic spectra of the Temozolomide drug and Temozolomide/HCM-Cellulose complex in were calculated by Time-Dependent Density Functional Theory (TD-DFT) for the investigation of the adsorption effect of the Temozolomide drug over HCM-Cellulose on maximum wavelength. As a result, the feasibility of using HCM-Cellulose to deliver Temozolomide to diseased cells has been established.

Hydrolysis and Enantiodiscrimination of (R)- and (S)-Oxazepam Hemisuccinate by Methylated β-Cyclodextrins: An NMR Investigation

Partially and exhaustively methylated β-cyclodextrins [(2-methyl)-β-CD (MCD), heptakis-(2,6-di-O-methyl)-β-CD (DIMEB), and heptakis-(2,3,6-tri-O-methyl)-β-CD (TRIMEB)] have been compared in the hydrolysis and enantiodiscrimination of benzodiazepine derivative (R)- or (S)-oxazepam hemisuccinate (OXEMIS), using nuclear magnetic resonance (NMR) spectroscopy as an investigation tool. After 6 h, MCD induced an 11% hydrolysis of OXEMIS, remarkably lower in comparison with underivatized β-CD (48%), whereas no hydrolysis was detected in the presence of DIMEB or TRIMEB after 24 h. DIMEB showed greater ability to differentiate OXEMIS enantiomers in comparison to TRIMEB, by contrast MCD did not produce any splitting of racemic OXEMIS resonances. Both enantiomers of OXEMIS underwent deep inclusion of their phenyl pendant into cyclodextrins cavities from their wider rims, but tighter complexes were formed by DIMEB with respect to TRIMEB.

Conjugate Addition of Carbon Acids to β,γ-Unsaturated α-Keto Esters: Product Tautomerism and Applications for Asymmetric Synthesis of Benzo[a]phenazin-5-ol Derivatives

A correlation between the equilibrium ratio of tautomeric products generated by the asymmetric Michael reactions of cyclic carbon acids with β,γ-unsaturated α-keto esters and the chemical shift of the α-proton in starting nucleophilic substrates was revealed which makes equilibration predictable. New tetrahydropyran-fused benzo[a]phenazins were enantioselectively (up to 99% ee) synthesized from β,γ-unsaturated α-keto esters and benzo[a]phenazin-5-ol, a powerful anti-cancer agent sAJM589. Facile recyclability of catalyst Ia in the catalytic reactions was demonstrated.