Exploring potential coformers for oxyresveratrol using principal component analysis

Ag@Au core-shell nanoparticle-based surface-enhanced Raman scattering coupled with chemometrics for rapid determination of chloramphenicol residue in fish

The alarming increase in drug-resistant bacteria in fish resulting from the misuse of antibiotics poses a significant threat to ecosystems and human health. Therefore, the development of a reliable approach for detecting antibiotic residues in fish is crucial. In this study, a rapid and simple method for detecting chloramphenicol (CAP) residue in tilapia was developed using surface-enhanced Raman scattering (SERS) combined with chemometric algorithms. Silver and gold core-shell nanoparticles (Ag@Au CSNPs) were used as SERS nanosensors to achieve strong signal amplification with an enhancement factor of 2.67 × 106. The results demonstrated that the variable combination population analysis-partial least square (VCPA-PLS) model combined with the standard normal variable transformation pretreatment method exhibited the best predictive performance with a detection limit of 1 × 10-5 µg/mL. Thus, an SERS technique was established based on Ag@Au CSNPs combined with VCPA-PLS to rapidly detect CAP in tilapia.

Characterization of the molecular interactions between resveratrol derivatives and death-associated protein kinase 1

Death-associated protein kinase 1 (DAPK1), a Ca2+/calmodulin-regulated serine/threonine kinase, regulates cell apoptosis and autophagy and has been implicated in the pathogenesis of Alzheimer's disease (AD). Targeting DAPK1 may be a promising approach for treating AD. In our previous study, we found that a natural polyphenol, resveratrol (1), is a moderate DAPK1 inhibitor. In the present study, we investigated the interactions between natural and synthetic derivatives of 1 and DAPK1. Binding assays including intrinsic fluorescence quenching, protein thermal shift and isothermal titration calorimetry indicated that oxyresveratrol (3), a hydroxylated derivative, and pinostilbene (5), a methoxylated derivative, bind to DAPK1 with comparable affinity to 1. The enzymatic assay showed that 3 more effectively inhibits the intrinsic ATPase activity of DAPK1 compared with 1. Crystallographic analysis revealed that the binding modes of the methoxylated derivatives were different from those of 1 and 3, resulting in a unique interaction. Our results suggest that 3 may be helpful in treating AD and provide a clue for the development of promising DAPK1 inhibitors.

Improving the dissolution behaviors and bioavailability of abiraterone acetate via multicomponent crystal forms

Abiraterone acetate (ABA), the first-line drug for the treatment of metastatic castration resistant prostate cancer (mCRPC), is administered at a high daily dosage of 1000 mg due to its poor solubility, and its fasted absolute oral bioavailability is estimated to be less than 10%. In this work we have focused on developing multicomponent forms with improved dissolution behaviors and bioavailability. Two salts of ABA with malonic acid (ABA-MA) and saccharin (ABA-SAC), and five cocrystals with trans-aconitic acid (ABA-TAA), 1-hydroxy-2-naphthoic acid (ABA-1HNA), pyrocatechol (ABA-PCA), resorcinol (ABA-RES) and hydroquinone (ABA-HDE) were successfully obtained. Their crystal structures were elucidated by single crystal X-ray diffraction, and these multicomponent forms were fully characterized by powder X-ray diffraction, thermal analysis and Fourier Transform Infrared spectra. Among them, ABA-TAA cocrystal shows substantial enhancements both in the solubility and intrinsic dissolution rates in different buffer solutions. In the meantime, we unexpectedly found the gelation of ABA-MA salt and ABA-SAC salt in pH 2.0 buffer solution. The gel-like materials generated on the surface of drug will suppress the release of ABA. Moreover, in vivo pharmacokinetic study on beagle dogs was conducted for ABA-TAA cocrystal preparation and ABA commercial product, and ABA-TAA cocrystal preparation shows enhanced absorption. These advantages in dissolution behaviors and bioavailability demonstrate the potential of ABA-TAA cocrystal to be a better candidate for the treatment of mCRPC compared with ABA.

Amino acids and its pharmaceutical applications: A mini review

Amino acids are natural compounds that can be safely used in pharmaceutical applications. Considering the great interest in the amino acids used in the pharmaceutical industry, this article presents an overview of investigations reported in recent years. In this regard, the first sections begin with an introductory description of the properties, classification and safety of amino acids, while in the other sections the most common methods for the preparation of amino acids formulations and their application on solubilization, permeation and stabilization of several active pharmaceutical ingredients are described. Furthermore, available data about the multicomponent systems approach is included. Lastly, the impact of amino acids formulations on therapeutic efficacy is explored. The advantages illustrated suggest that amino acids are capable of improving the biopharmaceutical properties of drugs.

Rapid detection and prediction of chloramphenicol in food employing label-free HAu/Ag NFs-SERS sensor coupled multivariate calibration

Considering growing food safety issues, hollow Au/Ag nano-flower (HAu/Ag NFs) nanosensor has been synthesized for label-free and ultrasensitive detection of chloramphenicol (CP) via integrating the surface-enhanced Raman scattering (SERS) and multivariate calibration. As the anisotropic plasmonic nanomaterials, HAu/Ag NFs had numerous nano-chink on their surface, which offered huge hotspots for analytes. CP generated a strong SERS signal while adsorbed on the surface of HAu/Ag NFs and noted excellent linearity with 1st derivative-competitive adaptive reweighted sampling-partial least squares (CARS-PLS) in the range of 0.0001-1000 µg/mL among the four applied multivariate calibrations. Additionally, CARS-PLS generated the lowest prediction error (RMSEP) of 0.089 and 0.123 µg/mL for milk and water samples, respectively, and any CARS-PLS model could be used for both samples according to T-test results (P > 0.05). The intra- and interday recovery for both samples were in the range of 92.62-96.74% with CV < 10%, suggested the proposed method has excellent accuracy and precision.

Four Novel Pharmaceutical Cocrystals of Oxyresveratrol, Including a 2 : 3 Cocrystal with Betaine

Cocrystal engineering can alter the physicochemical properties of a drug and generate a superior drug candidate for formulation design. Oxyresveratrol (ORV) exhibits a poor solubility in aqueous environments, thereby resulting in a poor bioavailability. Extensive cocrystal screening of ORV with 67 cocrystal formers (coformers) bearing various functional groups was therefore conducted using grinding, liquid-assisted grinding, solvent evaporation, and slurry methods. Six cocrystals (ORV with betaine (BTN), L-proline (PRL), isonicotinamide, nicotinamide, urea, and ethyl maltol) were found, including four novel cocrystals. Powder X-ray diffraction, low frequency Raman spectroscopy, and thermal analysis revealed unique crystal forms in all obtained samples. Conventional Raman and infrared data differentiated the cocrystals by the presence or absence of a hydrogen bond interacting with the aromatic ring of ORV. The crystal structures were then elucidated by single-crystal X-ray diffraction. Two new cocrystals consisting of ORV : BTN (2 : 3) and ORV : PRL : H₂O (1 : 2 : 1) were identified, and their crystal structures were solved. We report novel cocrystalline solids of ORV with improved aqueous solubilities and the unique cage-like crystal structures.

Pharmaceutical cocrystals: A review of preparations, physicochemical properties and applications

Pharmaceutical cocrystals are multicomponent systems in which at least one component is an active pharmaceutical ingredient and the others are pharmaceutically acceptable ingredients. Cocrystallization of a drug substance with a coformer is a promising and emerging approach to improve the performance of pharmaceuticals, such as solubility, dissolution profile, pharmacokinetics and stability. This review article presents a comprehensive overview of pharmaceutical cocrystals, including preparation methods, physicochemical properties, and applications. Furthermore, some examples of drug cocrystals are highlighted to illustrate the effect of crystal structures on the various aspects of active pharmaceutical ingredients, such as physical stability, chemical stability, mechanical properties, optical properties, bioavailability, sustained release and therapeutic effect. This review will provide guidance for more efficient design and manufacture of pharmaceutical cocrystals with desired physicochemical properties and applications.

Metabolites Identification of Chemical Constituents From the Eggplant (Solanum melongena L.) Calyx in Rats by UPLC/ESI/qTOF-MS Analysis and Their Cytotoxic Activities

Eggplant (Solanum melongena L.) Calyx is a medicinal and edible traditional Chinese medicine with anti-inflammatory, anti-oxidant, and anti-cancer properties. However, the pharmacodynamic components and metabolic characteristics remain unclear. Amide and phenylpropanoid were the two main constituents, and four amides, including n-trans-p-coumaroyltyramine (1), n-trans-p-coumaroyloctopamine (2), n-trans-p-coumaroylnoradrenline (3), n-trans-feruloyloctopamine (4), and a phenylpropanoid neochlorogenic acid (5) were selected. In this study, these five representative compounds showed cytotoxic activities on A549, HCT116, and MCF7 cells. In addition, the metabolites of 1–5 from the eggplant calyx in rats were identified. In total, 23, 37, 29, and 17 metabolites were separately characterized in rat plasma, urine, feces, and livers, by UPLC/ESI/qTOF-MS analysis. The metabolism of amides and phenylpropanoid was mainly involved in hydroxylation, methylation, glucuronidation, or sulfation reactions. Two hydroxylated metabolites (1-M2 and 2-M3) were clearly identified by comparison with reference standards. Rat liver microsome incubation experiments indicated that P450 enzymes could hydroxylate 1–5, and the methylation reaction of the 7-hydroxyl was also observed. This is the first study on the in vivo metabolism of these compounds, which lays a foundation for follow-up studies on pharmacodynamic evaluations and mechanisms.

Oxyresveratrol: Sources, Productions, Biological Activities, Pharmacokinetics, and Delivery Systems

Oxyresveratrol has recently attracted much research attention due to its simple chemical structure and diverse therapeutic potentials. Previous reviews describe the chemistry and biological activities of this phytoalexin, but additional coverage and greater accessibility are still needed. The current review provides a more comprehensive summary, covering research from 1955 to the present year. Oxyresveratrol occurs in both gymnosperms and angiosperms. However, it has never been reported in plants in the subclass Sympetalae, and this point might be of both chemotaxonomic and biosynthetic importance. Oxyresveratrol can be easily obtained from plant materials by conventional methods, and several systems for both qualitative and quantitative analysis of oxyresveratrol contents in plant materials and plant products are available. Oxyresveratrol possesses diverse biological and pharmacological activities such as the inhibition of tyrosinase and melanogenesis, antioxidant and anti-inflammatory activities, and protective effects against neurological disorders and digestive ailments. However, the unfavorable pharmacokinetic properties of oxyresveratrol, including low water solubility and poor oral availability and stability, have posed challenges to its development as a useful therapeutic agent. Recently, several delivery systems have emerged, with promising outcomes that may improve chances for the clinical study of oxyresveratrol.

Fingerprinting and Determination of Hepatotoxic Constituents in Polygoni Multiflori Radix Praeparata of Different Producing Places by HPLC

Polygoni Multiflori Radix Praeparata (PMRP) is used as Chinese herbal medicine with long history. However, reports about PMRP hepatotoxicity have increased recently, and producing area might be one reason. This article aims to figure out the relationship between producing area and hepatotoxic ingredients in PMRP. HPLC fingerprint for PMRP was established and the contents of gallic acid, trans-stilbene glycoside (TSG), emodin-8-O-β-D-glucoside (EG), emodin and physcion were determined. Clustering heatmap was implemented by TCMNPAS software，and principal component analysis was implemented by SPSS and SIMCA-P software. Hepatotoxic constituents' contents of PMRP from separate producing area were different. PMRP from Guangxi had the highest content of gallic acid, TSG, EG, emodin and physcion, followed by Hubei, Guangdong, Guizhou, Yunnan. PMRP from Henan had the lowest contents of hepatotoxic components. Hepatotoxic components' contents of PMRP in southern were higher than central China. This study carried out a preliminary qualitative and quantitative investigation on the PMRP from different producing places, which provided a basis for safe medication of PMRP.

Dry and Wet Mechanochemical Synthesis of Piroxicam and Saccharin Co-Crystals and Evaluation by Powder X-Ray Diffraction, Thermal Analysis and Mid- and Near- Infrared Spectroscopy

The purpose of this study is to investigate the effects of dry and wet mechanochemical synthesis on piroxicam (PX) and saccharin (SA) mixtures. For this purpose, PX and SA mixtures prepared by wet mechanochemical processes using three solvents and by dry mechanochemical synthesis were evaluated by mid-and near-infrared spectroscopy, powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). The mixtures of wet-type products were transformed into PX/SA 1:1 co-crystals. The effect of the solvent was key to the co-crystallization of PX and SA. The products from the dry process were transformed into the amorphous phase. For the sample of the amorphous mixture, two exothermic peaks due to crystallization were observed in the thermal analysis. Bulk PX was ground for the same number of times for transformation, but was not successfully transformed to the amorphous bulk; the same was observed for SA. It is suggested that the mutual existence of PX and SA promotes mutual amorphization.

Mechanochemistry: A Green Approach in the Preparation of Pharmaceutical Cocrystals

Mechanochemistry is considered an alternative attractive greener approach to prepare diverse molecular compounds and has become an important synthetic tool in different fields (e.g., physics, chemistry, and material science) since is considered an ecofriendly procedure that can be carried out under solvent free conditions or in the presence of minimal quantities of solvent (catalytic amounts). Being able to substitute, in many cases, classical solution reactions often requiring significant amounts of solvents. These sustainable methods have had an enormous impact on a great variety of chemistry fields, including catalysis, organic synthesis, metal complexes formation, preparation of multicomponent pharmaceutical solid forms, etc. In this sense, we are interested in highlighting the advantages of mechanochemical methods on the obtaining of pharmaceutical cocrystals. Hence, in this review, we describe and discuss the relevance of mechanochemical procedures in the formation of multicomponent solid forms focusing on pharmaceutical cocrystals. Additionally, at the end of this paper, we collect a chronological survey of the most representative scientific papers reporting the mechanochemical synthesis of cocrystals.

Determination of the physical state of a drug in amorphous solid dispersions using artificial neural networks and ATR-FTIR spectroscopy

The objective of the present study was to evaluate the use of artificial neural networks (ANNs) in the development of a new chemometric model that will be able to simultaneously distinguish and quantify the percentage of the crystalline and the neat amorphous drug located within the drug-rich amorphous zones formed in an amorphous solid dispersion (ASD) system. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy was used, while Rivaroxaban (RIV, drug) and Soluplus® (SOL, matrix-carrier) were selected for the preparation of a suitable ASD model system. Adequate calibration and test sets were prepared by spiking different percentages of the crystalline and the amorphous drug in the ASDs (prepared by the melting - quench cooling approach), while a 2⁴ full factorial experimental design was employed for the screening of ANN's structure and training parameters as well as spectra region selection and data preprocessing. Results showed increased prediction performance, measured based on the root mean squared error of prediction (RMSEp) for the test sample, for both the crystalline (RMSEp _(crystal) = 0.86) and the amorphous (RMSEp _(amorphous) = 2.14) drug. Comparison with traditional regression techniques, such as partial least square and principle component regressions, revealed the superiority of ANNs, indicating that in cases of high structural similarity between the investigated compounds (i.e., the crystalline and the amorphous forms of the same compound) the implementation of more powerful/sophisticated regression techniques, such as ANNs, is mandatory.