Chiral separation and modeling of baclofen, bupropion, and etodolac profens on amylose reversed phase chiral column

Recent Trends in Ibuprofen and Ketoprofen Electrochemical Quantification - A Review

Non-steroidal anti-inflammatory drugs are intensively manufactured, used, and regulated. However, these compounds incur toxic effects on gastrointestinal, cardiovascular, and renal systems when administered in high doses for extended periods. Additionally, once these drugs reach the ecosystems through various pathways, they become environmental contaminants and raise ecological concerns. Traditional detection methods proposed for non-steroidal anti-inflammatory drugs detection encompass certain limitations. In this context, the need for simple, cost-effective, sensitive, and selective detection methods that could improve the quality of analysis led the attention of the scientific community toward electrochemical sensors. The lowest limit of detection of ibuprofen (33.33 × 10-12 μmol L-1) was recorded for a sensor based on ibuprofen specific aptamer bound with nitrogen-doped graphene quantum dots and gold nanoparticles nanocomposite modified glassy carbon electrode using differential pulse voltammetry, while the lowest limit of detection reported for ketoprofen was 0.11 μmol L-1 when differential pulse voltammetry was used. This review focuses on the construction, analytical performances, and applicability of electrochemical sensors developed for ibuprofen and ketoprofen determination. This work covers 24 articles published between 2016 and 2022.

Enantioseparation, quantification, molecular docking and molecular dynamics study of five β-adrenergic blockers on Lux-Cellulose-2 column

Enantioseparation of five β-adrenergic blockers was studied using two mobile phases on a cellulose tris(3-chloro-4-methylphenylcarbamate) (Lux-Cellulose-2) chiral column in normal phase mode. The first mobile phase composed of n-hexane: ethanol: diethylamine 60: 40: 0.1 by volume has successfully resolved the chromatographic peaks of three pairs of β-adrenergic blockers namely, bisoprolol, carvedilol and atenolol. A mixture of n-hexane: ethanol: diethyl amine 75: 25: 0.1 by volume was used as the second mobile phase to separate the four pairs of enantiomers, metoprolol, carvedilol, nebivolol and atenolol with high resolution values. The mobile phases were pumped at a flow rate 1 mL/min with column temperature 25 °C using a UV detector at 230 nm. Molecular docking simulations of the five pairs of enantiomers was carried out in the cavities of the chiral stationary phase to gain a better understanding of the interaction between analyte enantiomers and chiral stationary phase and to better understand the mechanism of chiral recognition. According to the results, hydrogen bond interactions and π-π- interactions were the main types of interaction involved in the chiral recognition. Molecular dynamics simulation was performed to investigate the solvent effect on the interaction of the five pair of enantiomers in the chiral stationary phase cavity under dynamic conditions.

Cucurbituril-assisted sensitive fluorescence detection and quantitation of naproxen drug in wastewater samples: Guest-host characterization and HPLC investigation

Sensitive spectrofluorometric and liquid chromatography with fluorescence detection methods have been developed for detection and determination of naproxen drug in the presence of cucurbit7uril (CB7). Fluorescence signals have been improved with the addition of CB7 to the drug aqueous solution. Fluorescence spectroscopy, mass spectrometry, ¹H-NMR, and liquid chromatography with fluorescence detection were used to investigate the guest-host interaction of naproxen drug and cucurbiturils. Naproxen was found to form a supramolecular complex with CB7 that had a high formation constant. The optimal conditions for the interaction were discovered using spectroflurometry to be 0.2 mg/ml of CB7, 2.4 μg/ml of naproxen drug, and pH10. A 1:1 complex between naproxen and CB7 is revealed by proton NMR and tandem mass spectrometry. Using the standard addition calibration method, an HPLC with a fluorescence detector was used to detect naproxen in influent and effluent wastewater samples. Finally, it was discovered that the measured concentrations of naproxen in the influent and the effluent wastewater were 1.87 × 10^-4 ppb and 2.1 × 10^-5 ppb, respectively. This was done by sample enrichment, which reduced the 1000 mL into 1 ml.

Evaluation of Chiral Fungicide Penflufen in Legume Vegetables: Enantioseparation and Its Mechanism, Enantioselective Behaviors, and Risk Assessment

Illustrating the enantioselective behaviors of the novel chiral fungicide penflufen was extremely important for ecological safety and human health. For penflufen enantiomers, an excellent separation method including a short analysis time (4 min), a high sensitivity (2 ng/g), and lesser consumption of an organic solvent was first established through supercritical fluid chromatography-tandem mass spectrometry. The enantioseparation mechanism was explained by computational chemistry, and the stronger binding ability of S-(+)-penflufen with cellulose tris-(3-chloro-4-methylphenylcarbamate) (the chiral stationary phase OZ-3 column) contributed to the posterior elution. In legume vegetables, penflufen dissipation was the fastest in Pisum sativum Linn plants (half-life, 1 day) and the slowest in Glycine max plants (half-lives, 11.3-12.9 days). After 30, 50, and 40 days, the rac-penflufen residues were lower than the maximum residue level value in the Electronic Code of Federal Regulations (10 ng/g) in G. max, P. sativum Linn, and Vigna unguiculata, respectively. Abundant S-(+)-penflufen was found in these plants with stereoisomeric excess (se) changes being >10% in the initial stage, so the risk assessment might be driven by S-(+)-penflufen. However, the se changes were <10% in V. unguiculata plants, and the risk assessment might be calculated based on rac-penflufen. Moreover, penflufen enantiomers could be transferred from legume vegetables to soils, and the concentrations increased with time. The high persistence and medium mobility of penflufen in soils might lead to potential groundwater contamination, which was noteworthy. These results could contribute to a more accurate risk assessment of penflufen in legume vegetables.

The Target Determination and the Mechanism of Action of Chiral-Antimalarial Drugs: A Docking Approach

Due to an undecided target and the prescription of chiral-aminoquinolines (chloroquine, primaquine and quinacrine) in the racemic form, the mechanism of action as well as the reason of causing side effects become unclear. Based on computationally evaluated literature data, the things determined theoretically were (i) the target of aminoquinolines during antimalarial activity, (ii) the mechanism of action of chiral-aminoquinolines and (iii) biologically active enantiomers of aminoquinolines. For the presented study, the enantiomeric binding affinities of aminoquinolines with all the targets claimed by other scientists were calculated, and then used in interpretation with the help of many investigations done/observed by others. The results were very interesting based on which, a new and acceptable mechanism of action of chiral-aminoquinolines during malaria curing step, is given for the first time. The current docking study not only resolves the questionable point about a definite target of aminoquinolines but also makes the mechanism of action understandable.

Enantiomeric separation of six beta-adrenergic blockers on Chiralpak IB column and identification of chiral recognition mechanisms by molecular docking technique

Enantiomeric separation of six β-adrenergic blockers was systematically studied for the first time on a polysaccharide-based chiral stationary phase, i.e. Chiralpak IB, under the normal-phase mode. The effect of alcohol modifiers, alcohol content and basic additive on enantiomeric separation was evaluated and optimized. Under the optimal conditions, the enantiomers of atenolol, bevantolol, cartelol, esmolol, metoprolol and propranolol were all baseline resolved with resolutions of 1.50, 8.56, 2.05, 2.11, 3.56 and 4.02, respectively. Additionally, molecular docking was tested to explain chiral recognition mechanisms of this set of the drug enantiomers on Chiralpak IB. The details of the various interactions affecting enantiomeric separation were confirmed from the molecular level and the modeling data were in agreement with the chromatographic results concerning the enantioselectivity.

Enantioseparation using carboxymethyl-6-(4-methoxybenzylamino)-β-cyclodextrin as a chiral selector by capillary electrophoresis and molecular modeling study of the recognition mechanism

In this study, carboxymethyl-6-(4-methoxybenzylamino)-β-cyclodextrin (CMCDPN) was synthesized for the first time and managed to be used as a chiral selector to enantioseparate 13 kinds of chiral drugs by capillary electrophoresis.

On the applicability of functional-group symmetry-adapted perturbation theory and other partitioning models for chiral recognition - the case of popular drug molecules interacting with chiral phases

The applicability of symmetry-adapted perturbation theory (SAPT) and functional-group SAPT (F-SAPT) to study chiral recognition is investigated on an example of three popular chiral drug molecules: ibuprofen, norepinephrine, and baclofen, interacting with phenethylamine or proline - two molecules that are often used as chiral phases in chromatography. The comparison of the F-SAPT with the interacting quantum atoms (IQA) approach is also provided. Accurate estimation of energetic differences of the non-covalent intermolecular complexes composed of two chiral molecules is a necessary prerequisite for the possibility of a prediction of the chiral recognition. The SAPT method with interacting molecules described on the density functional theory level provides accurate total interaction energies, while the F-SAPT approach is the most useful in determining which functional groups are responsible for strengthening or weakening of the interaction between chiral molecules. The largest difference in the interaction energies has been calculated for the baclofen-phenethylamine and norepinephrine-phenethylamine pairs, while the smallest for the ibuprofen-proline and baclofen-proline ones. In most cases, the intermolecular interaction is found to be composed of a strong directional hydrogen bond, which was stabilized by two or more weaker non-covalent interactions between groups (in accordance with the phenomological three-point rule), but in several cases more subtle factors are responsible for larger stability of one diastereoisomer, like the stabilization of the conformation involving two noninteracting functional groups attached to a chiral atom through intramolecular attraction. Additionally, the simulated IR spectra were analyzed for all pairs of diastereoisomeric complexes and the red- and blue-shifts of characteristic bond vibrations were discussed in the context of inter-group interactions.

Role of Unani Medicines in Cancer Control and Management

Background:

Cancer is a havoc and killer disease. Several ways including allopathic chemotherapy have been used in the cancer treatment. Allopathic chemotherapy has several limitations and side effects. Unani medicine is also one of the therapies to cure cancer.

Objective:

In this type of treatment, herbal drugs are used for the treatment and prevention of cancer. The main attractive thing about herbal drug is no side effect as compared to allopathic chemotherapy.

Methods:

Actually, herbal drugs are the extracts of medicinal plants. The plant extracts are obtained by crushing and heating the main part of the plants; showing anticancer activity. The main plants used in the treatment of cancer are oroxylum indicum, dillenia indica, terminalia arjuna etc.

Results:

Mainly the cancers treated are of digestive system, breast, cervical, brain, blood, bone, lungs, thyroid, uterine, bladder, throat etc.

Conclusion:

The present review article discusses the importance of Unani system of medicine for the treatment of cancer. Besides, the future perspectives of Unani medicine in cancer treatment are also highlighted.

Enantioseparation and determination of flumequine enantiomers in multiple food matrices with chiral liquid chromatography coupled with tandem mass spectrometry

The present work firstly described the enantioseparation and determination of flumequine enantiomers in milk, yogurt, chicken, beef, egg, and honey samples by chiral liquid chromatography-tandem mass spectrometry. The enantioseparation was performed under reversed-phase conditions on a Chiralpak IC column at 20°C. The effects of chiral stationary phase, mobile phase components, and column temperature on the separation of flumequine enantiomers have been studied in detail. Target compounds were extracted from six different matrices with individual extraction procedure followed by cleanup using Cleanert C18 solid phase extraction cartridge. Good linearity (R² >0.9913) was obtained over the concentration range of 0.125 to 12.5 ng g^-1 for each enantiomer in matrix-matched standard calibration curves. The limits of detection and limits of quantification of two flumequine enantiomers were 0.015-0.024 and 0.045-0.063 ng g^-1 , respectively. The average recoveries of the targeted compounds varied from 82.3 to 110.5%, with relative standard deviation less than 11.7%. The method was successfully applied to the determination of flumequine enantiomers in multiple food matrices, providing a reliable method for evaluating the potential risk in animal productions.

Chiral separation and a molecular modeling study of eight azole antifungals on the cellulose tris(3,5-dichlorophenylcarbamate) chiral stationary phase

Four immobilized polysaccharide-based chiral stationary phases have been examined for their enantioselectivity on azole analytes using normal phase liquid chromatography.