High-Performance Chromatographic Separation of Cerebrosides

High-performance thin layer chromatography (HPTLC) is a very robust, fast, and inexpensive technique that enables separation of complex mixtures. Here, we describe the analytical separation of glucosylceramide and galactosylceramide by HPTLC. This technique can be used for quantitation purposes but also with small modification for subsequent mass spectrum analysis for structural determination.

Biocompatible magnetite nanoparticles coated with ionic liquid-based surfactantas a hydrophilic sorbent for dispersive solid phase microextraction of cephalosporins prior to their quantitation by HPTLC

Extraction of highly hydrophilic compounds from biological fluids including urine or plasma samples is a dilemma due to high hydrophilicity of the matrix itself. The main aim of the current work is to explore the competence of ionic liquid (IL)-based surfactant-coated mineral oxide nanoparticles (NPs) in dispersive solid-phase microextraction (d-SPME) of highly hydrophilic analytes taking cefoperazone (CPZ) as a model analyte for the study. The IL-based surfactant coated Fe₃O₄ NPs is utilized as an innovative adsorbent for the separation and pre-concentration of CPZ after intramuscular injection (I.M) in rabbits. The utilized magnetite NPs were synthesized via simple and reliable co-precipitation procedure, which doesn't require any air-free environment and depends on a single iron (III) salt. Characterization of the as-synthesized NPs was achieved by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) and energy dispersive X-ray (EDX). Surface area measurements show that Fe₃O₄ NPs have large surface area of 75 m² g^-1. The developed approach utilizes the unique properties of the IL-based surfactant including multiple polar interaction types provided by the polar head in addition to merits of Fe₃O₄ nanoparticles, which include large adsorptive capacity and magnetic properties, to improve separation, save time, and achieve satisfactory recovery. Comprehensive study was developed for the factors, that affect the adsorption capacity such as pH, NPs amount, IL-based surfactant concentration, ionic strength, adsorption time, and desorption conditions. Moreover, the adsorption data was fitted to Langmuir and second-order kinetic models as reflected by the reasonable determination coefficients of 0.9319 and 0.9726, respectively. Under the optimized conditions, the developed approach achieves good correlation coefficient of 0.9975, and 0.9981 over linearity range of 0.7-12.0 and 4.0-50.0 µg mL^-1 for both CPZ standard solutions and spiked rabbit plasma, respectively. It also provides good sensitivity expressed by the low values of limit of detection (LOD) of 0.2 and 1.2 µg mL^-1 and limit of quantitation (LOQ) of 0.7 and 4.0 µg mL^-1 for both the standard solutions and spiked plasma, respectively. The developed approach was also applied successfully for monitoring CPZ in rabbit plasma samples with satisfactory recovery % (83-110). In addition, a detailed pharmacokinetic study is performed where pharmacokinetic parameters of CPZ in rabbit plasma samples were calculated.

A critical assessment of transmethylation procedures for n-3 long-chain polyunsaturated fatty acid quantification of lipid classes

Lipid transmethylation methods described in the literature are not always evaluated with care so to insure that the methods are effective, especially on food matrix or biological samples containing polyunsaturated fatty acid (PUFA). The aim of the present study was to select a method suitable for all lipid species rich in long chain n-3 PUFA. Three published methods were adapted and applied on individual lipid classes. Lipid (trans)methylation efficiency was characterized in terms of reaction yield and gas chromatography (GC) analysis. The acid-catalyzed method was unable to convert triglycerides and sterol esters, while the method using an incubation at a moderate temperature was ineffective on phospholipids and sterol esters. On the whole only the method using sodium methoxide and sulfuric acid was effective on lipid classes taken individually or in a complex medium. This study highlighted the use of an appropriate (trans)methylation method for insuring an accurate fatty acid composition.

Nicotine quantity and packaging disclosure in smoked and smokeless tobacco products in India

OBJECTIVES

A variety of smoked and smokeless tobacco products with varying nicotine content are accessible in India. Nicotine quantity in tobacco products has direct bearing on tobacco dependence. Our objective was to estimate nicotine content in various types of smoked and smokeless products. Disclosure for essential health warning was also checked.

MATERIALS AND METHODS

Liquid-liquid extraction was used for nicotine extraction and high-performance thin layer chromatography technique was applied for quantification of nicotine in seventy-one smoked and smokeless tobacco products.

RESULTS

Significant variation in nicotine content was observed across products. In smoked tobacco, nicotine content varied from 1.01 to 13.0 mg/rod, while in smokeless tobacco products it ranged from 0.8 mg/g to 50.0 mg/g. Moisture content varied from 9% to 21%.

CONCLUSION

This work lists a range of smoked and smokeless tobacco products available in this region. We report a wide variability in nicotine quantity across smoked and smokeless tobacco products. Such variation in nicotine content may have important implications for tobacco cessation interventions and policies.

Pharmacognostic Screening of Piper trichostachyon Fruits and its Comparative Analysis with Piper nigrum Using Chromatographic Techniques

BACKGROUND

Piper trichostachyon is a wild, endemic Piper species from Western Ghats of India. The folklore healers of Belagavi region use this plant, similar to Piper nigrum.

AIMS

The present study investigates the comparison between P. nigrum and P. trichostachyon using pharmacognostic parameters.

MATERIALS AND METHODS

Pharmacognostic evaluation was carried out in terms of morphological, microscopic characters, and phytochemical analysis using standard methods. Comparative physicochemical analysis between P. trichostachyon and P. nigrum was also carried out through estimation of micro-macro nutrients, high-performance thin layer chromatography (HPTLC) investigation and using piperine as a marker compound for reversed phase-ultra flow liquid chromatographic (RP-UFLC) technique.

RESULTS

P. trichostachyon grows in the forests, and the fruits are morphologically similar to P. nigrum fruits, so the name in Kannada "Kaadu Kalu menasu" (wild/forest black pepper). The microscopy revealed the presence of stone cells, starch grains, oil cells and globules, beaker cells, and yellowish brown pigment layer, parenchymatous cells. The presence of alkaloids, oil, and tannins were observed in P. trichostachyon fruits. The HPTLC studies visibly indicated differences among two species with 12 peaks and varied banding pattern. RP-UFLC results showed less amount of piperine in P. trichostachyon (0.05 ± 0.002 mg/g) than in P. nigrum (16.14 ± 0.807 mg/g).

CONCLUSION

The study reports on pharmacognostic parameters of P. trichostachyon for the 1(st) time and will be useful for the identification and authentication. The comparative HPTLC and RP-UFLC studies resolve the differentiation impasse among two species. However, further biological efficacy studies are required to establish its use in traditional medicine.

SUMMARY

Piper trichostachyon grows in the forests, and the fruits are morphologically similar to Piper nigrum fruitsThe microscopy of P. trichostachyon revealed the presence of stone cells, starch grains, oil cells and globules, beaker cells and yellowish brown pigment layer, parenchymatous cellsThe high-performance thin layer chromatography studies visibly indicated differences among two species with varied banding patternReversed phase-ultra flow liquid chromatographic results showed less amount of piperine in P. trichostachyon than in P. nigrum. Abbreviation used: HPTLC: High Performance Thin Layer Chromatography, RP-UFLC: Reversed phase-ultra flow liquid chromatographic analysis, DST: Length of line, Maj: Length of large half axis for ellipse RDS - radius for circle, Rf: Retention Factor, TS: Transverse Section, TLC: Thin Layer Chromatography.

Chromatographic Study of Novel Heteronuclear Complexes with Schiff Base as Main Ligand

The properties of 12 new heterodi- and heterotrinuclear complexes having general formulae [Cu2Ln(L)2(NO3)(H2O)2](NO3)2·3H2O [where Ln = Pr (1), Nd (2), Sm (3) and Eu (4)], and [CuLn(L)(NO3)2(H2O)3MeOH]NO3·MeOH [where Ln = Gd (5), Tb (6), Dy (7), Ho (8), Ef (9), Tm (10), Yb (11) and Lu (12)], and their main ligand [L = C19H18N2O4Br2 = N,N'-bis(5-bromo-3-methoxysalicylidene)propylene-1,3-diamine] have been characterized by chromatographic analyses. The parameter of relative lipophilicity (RM0) of the tested compounds was determined experimentally by reversed-phase high-performance thin layer chromatography method with mixtures of methanol and water as a mobile phase. We also described interactions between chromatographed substances and various surfaces (silica-SiO2 and modified by hydrocarbon chains-RP-2, RP-8, RP-18 phases). This study also investigates the effect of pH of the mobile phase on the retention on the polar stationary phase. Thin layer chromatography combined with magnetic and electric field has been proposed as a complementary method for the determination of physicochemical properties of the investigated compounds. The chromatograms in the field and outside of it were developed simultaneously in three identical chromatographic chambers. One of them was placed in external magnetic field of 0.4 T inductivity, and the second in external electrical field. In magnetic and electric fields, retention of some complexes changed, which indicated that the presence of these fields influenced physicochemical properties of the compounds and their interactions with the stationary phase.