Detailed quantum mechanical studies on bioactive benzodiazepine derivatives and their adsorption over graphene sheets.

Estazolam (Z1) and related derivatives, adinazolam (Z2), alprazolam (Z3), 4-hydroxyalprazolam (Z4) and triazolam (Z5) have been studied by using various computational tools to analyze their geometry and spectral characteristics. The compounds were found to interact with graphene monolayer results shows that there is enhancement in various physico-chemical descriptors and surface enhanced Raman spectra (SERS). The various reactive descriptors obtained from the FMO analysis predict the reactive nature of the compound. The various lone pair/sigma to pi conjugation was analyzed using NBO formalism, which provides valuable information about intra molecular electron transfer which is vital in predicting the inherent stability of the molecule. Simulated electronic spectra using TD-DFT and CAM-B3LYP functional are discussed in detail with respect to electronic transitions and light harvesting efficiency. Suitability of candidates as a photo sensitizer in dye sensitized solar cells was studied and 4-Hydroxyalprazolam is identified as a suitable candidate. Nucleophilic and electrophilic regions of the molecules are identified using MESP, which adds to the reactivity information. It can be seen that the highest interaction energy has been obtained in the case of the Z5-graphene system, while the lowest interaction energy has been obtained in the case of the Z1-graphene system. Docking indicates that the ligands adsorbed over graphene also form stable complexes with the receptors as indicated by the high binding affinity energy values.

A Rapid Detection Method for On-site Screening of Estazolam in Beverages with Au@Ag Core-shell Nanoparticles Paper-based SERS Substrate.

Estazolam (EST) is a common sedative-hypnotic drug with a risk of abuse. Therefore, rapid on-site detection of EST is necessary to control the abuse of EST. In this paper, a fast, simple, and sensitive method is demonstrated for the detection of EST in both water and beverages, using surface-enhanced Raman spectroscopy (SERS) techniques. Au@Ag core-shell nanoparticles (NPs) assembled on the filter paper as a SERS substrate exhibit good applicability and practicality. At the same time, density functional theory (DFT) is used to assign the vibration mode of the EST molecules, which can be used as a guide for subsequent experiments. The lowest detectable concentration of EST in aqueous solution can be as low as 5 mg/L, and signal uniformity is excellent (RSD687 = 5.56%, RSD1000 = 4.35%). In addition, EST components artificially added to orange juice and pomegranate juice can be effectively detected by simple pretreatment with a minimum detection concentration as low as 10 mg/L. Therefore, this study found that the use of Au@Ag core-shell nanoparticles paper-based SERS substrate provides a quick and easy method for the detection of illegally added drugs in beverages.

[A Forensic Autopsy Case in which Sulpiride and Estazolam Were Detected in an Adipoceratous Cadaver by LC-MS/MS].

We had a forensic autopsy case in which drugs were detected in a cadaver that had been stored in a cold and wet condition for 5 years. The skin of the cadaver was hard, and the color was partly whitish or dark brown. Though the cadaver had transformed into adipocere in the wet and cold condition, QuEChERS extraction and LC-MS/MS revealed the presence of sulpiride and estazolam in the femoral muscle and bone marrow. The concentrations of sulpiride and estazolam in the femoral muscle were 10.6 ng/g and 39.9 ng/g, respectively. The result of a drug screening test led not only to the cause of death but also to the personal identification of the cadaver. The individual had a history of drug taking, which had been stored in his medical records at the hospital for a long time. The fact of taking sulpiride and estazolam at the same time was characteristic, and it was useful in identifying the cadaver in this case. The progress in analytical technology has made possible the detection of particle drugs from old or adipoceratous cadavers, but there have been no reports of particle drugs being detected in a cadaver that had been dead for 5 years and had transformed to adipocere, as in our present case. The analytical results by LC-MS/MS were certainly important for the diagnosis of the cause of death, and, moreover, they were useful for the purpose of personal identification.

Benzodiazepine stability in postmortem samples stored at different temperatures.

Benzodiazepine (lorazepam, estazolam, chlordiazepoxide, and ketazolam) stability was studied in postmortem blood, bile, and vitreous humor stored at different temperatures over six months. The influence of NaF, in blood and bile samples, was also investigated. A solid-phase extraction technique was used on all the studied samples, and benzodiazepine quantification was performed by high-performance liquid chromatography-diode-array detection. Benzodiazepine concentration remained almost stable in all samples stored at -20°C and -80°C. Estazolam appeared to be a stable benzodiazepine during the six-month study, and ketazolam proved to be the most unstable benzodiazepine. A 100% loss of ketazolam occurred in all samples stored over 1 or 2 weeks at room temperature and over 8 or 12 weeks at 4°C, with the simultaneous detection of diazepam. Chlordiazepoxide suffered complete degradation in all samples, except preserved bile samples, stored at room temperature. Samples stored at 4°C for 6 months had a 29-100% decrease in chlordiazepoxide concentration. The data obtained suggest that results from samples with these benzodiazepines stored long-term should be cautiously interpreted. Bile and vitreous humor proved to be the most advantageous samples in cases where degradation of benzodiazepines by microorganisms may occur.

[Determination of benzodiazepines by thermospray liquid chromatograph-mass spectrometer. Part 1. Nitrazepam, estazolam, bromazepam, flunitrazepam].

Thermospray liquid chromatography mass spectrometric method is described for the determination of the benzodiazepines (Nitrazepam, Estazolam, Bromazepam, Flunitrazepam). Reversed-phase liquid chromatography was performed using a 15 cm Shim-pack CLC-ODS (Shimadzu) column, with acetonitrile-water (40:60) + 0.1 M ammonium acetate as mobile phase, at a flow rate of 1.0 ml/min. The temperature of the vaporizer, block and TH of the source block were 166, 270 and 275 degrees C, respectively. Positive ion thermospray mass spectra by thermospray ionization (TSP ionization) mode or thermospray on filament ionization (filament-on ionization) mode were obtained. Formation of the MH+ ion was observed as a base peak under TSP ionization and filament-on ionization conditions and fragment ions were very few. On both ionization mode, peaks representing nitrazepam as MH+ at m/z 282 at a retention time (R.T.) of 6.4 min, from estazolam as MH+ at m/z 295 at an R.T. of 6.4 min, from bromazepam as MH+ at m/z 316 at an R.T. of 4.5 min and from flunitrazepam as MH+ at m/z 314 at an R.T. of 8.8 min. The detection limit for all the benzodiazepines under investigation was less than 0.5 ng (S/N = 9.4 +/- 4.6) using selected ion monitoring.

A new method for the determination in blood and urine of a novel triazolobenzodiazepine (estazolam) by HPLC.

In this study the authors report a new method to determine estazolam in blood and urine by high pressure liquid chromatography (HPLC). This compound is a triazolobenzodiazepine and shows an interesting psychopharmacological activity. The extraction from biological fluids was carried out using a mixture of ethylenechloride, methylenechloride, and ethylacetate (1:1:8). The HPLC analysis was carried out with a C18 column, using methanol:phosphate buffer (pH 7.5, 0.011M):acetonitrile (65:33:2) as mobile phase. The detector was set at lambda = 240 nm. The method shows good repeatability and a linear response in the range of 0.6 to 10 micrograms estazolam/mL both in serum and urine. A case of non-lethal acute intoxication in which the method was applied is also reported.