Journal of Pharmaceutical Analysis

Analysis of isoquinoline alkaloids from Mahonia leschenaultia and Mahonia napaulensis roots using UHPLC-Orbitrap-MSn and UHPLC-QqQLIT-MS/MS

Awantika Singh, Vikas Bajpai, Sunil Kumar, Ajay Kumar Singh Rawat, Brijesh Kumar

2017, 7(2): 77-86.

Abstract(173) PDF(9)

Abstract:
Mahonia leschenaultia (ML) and Mahonia napaulensis (MN) are less known and unexplored medicinal plants of the family Berberidaceae. They are used by the Todas of Nilgiris in their religious and medical practices but chemically less identified. Hence, we decided to do extensive phytochemical analysis to explore the potential of these plant extracts. An ultrahigh performance electrospray tandem mass spectrometry (UHPLC–ESI–MS/MS) method was successfully developed for qualitative analysis of the bioactive components in Mahonia species using Orbitrap Velos Pro mass spectrometer. Sixteen compounds were identified by comparison of their retention times and mass spectra (MS) with authentic standards and reported literature. Multi-stage mass spectra (MS2–8) for the identification of protoberberine and aporphine alkaloids showed the sequential expulsion of all the substituents attached with their basic skeleton followed by CO loss. Eight of the identified compounds (berberine, jatrorrhizine, palmatine, magnoflorine, isocorydine, glaucine, tetrahydropalmatine and tetrahydroberberine) were simultaneously determined by another UHPLC–ESI–MS/MS method under the multiple reactions monitoring (MRM) mode quantitatively using triple quadrupole linear ion trap mass spectrometer. The analytical method was validated for 8 bioactive compounds with overall recovery in the range 98.5%–103.6%(RSD≤2.2%), precise (RSD≤2.07%) and linear (r≥0.9995) over the concentration range of 0.5–1000 ng/mL and successfully applied in ML and MN roots, which suggests the suitability of the proposed approach for the routine analysis of Mahonia species and their quality control.

N-glycans released from glycoproteins using a commercial kit and comprehensively analyzed with a hypothetical database

Xue Sun, Lei Tao, Lin Yi, Yilan Ouyang, Naiyu Xu, Duxin Li, Robert J. Linhardt, Zhenqing Zhang

2017, 7(2): 87-94.

Abstract(138) PDF(6)

Abstract:
The glycosylation of proteins is responsible for their structural and functional roles in many cellular activities. This work describes a strategy that combines an efficient release, labeling and liquid chromatography–mass spectral analysis with the use of a comprehensive database to analyze N-glycans. The analytical method described relies on a recently commercialized kit in which quick deglycosylation is followed by rapid labeling and cleanup of labeled glycans. This greatly improves the separation, mass spectrometry (MS) analysis and fluorescence detection of N-glycans. A hypothetical database, constructed using GlycResoft, provides all compositional possibilities of N-glycans based on the common sugar residues found in N-glycans. In the initial version this database contains >8,700 N-glycans, and is compatible with MS instrument software and expandable. N-glycans from four different well-studied glycoproteins were analyzed by this strategy. The results provided much more accurate and comprehensive data than that had been previously reported. This strategy was then used to analyze the N-glycans present on the membrane glycoproteins of gastric carcinoma cells with different degrees of differentiation. Accurate and comprehensive N-glycan data from those cells was obtained efficiently and their differences were compared corresponding to their differentiation states. Thus, the novel strategy developed greatly improves accuracy, efficiency and comprehensiveness of N-glycan analysis.

An improved LC–MS/MS method for the quantification of alverine and para hydroxy alverine in human plasma for a bioequivalence study

Dhiraj M. Rathod, Keyur R. Patel, Hiren N. Mistri, Arvind G. Jangid, Pranav S. Shrivastav, Mallika Sanyal

2017, 7(2): 95-102.

Abstract(121) PDF(5)

Abstract:
A highly sensitive and selective high performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of alverine (ALV) and its active metabolite, para hydroxy alverine (PHA), in human plasma. For sample preparation, solid phase extraction of analytes was performed on Phenomenex Strata-X cartridges using alverine-d5 as the internal standard. The analytes were separated on Symmetry Shield RP18 (150 mm×3.9 mm, 5 μm) column with a mobile phase consisting of acetonitrile and 10 mM ammonium formate (65:35, v/v). Detection and quantitation was done by electrospray ionization mass spectrometry in the positive mode using multiple reaction monitoring. The assay method was fully validated over the concentration range of 15.0–15,000 pg/mL for ALV and 30.0–15,000 pg/mL for PHA. The intra-day and inter-day accuracy and precision (%CV) ranged from 94.00%to 96.00%and 0.48%to 4.15%for both the analytes. The mean recovery obtained for ALV and PHA was 80.59% and 81.26%, respectively. Matrix effect, expressed as IS-normalized matrix factor ranged from 0.982 to 1.009 for both the analytes. The application of the method was demonstrated for the specific analysis of ALV and PHA for a bioequivalence study in 52 healthy subjects using 120 mg ALV capsules. The assay reproducibility was also verified by reanalysis of 175 incurred subject samples.

Investigation of binding behaviour of procainamide hydrochloride with human serum albumin using synchronous, 3D fluorescence and circular dichroism

Kirthi Byadagi, Manjunath Meti, Sharanappa Nandibewoor, Shivamurti Chimatadar

2017, 7(2): 103-109.

Abstract(184) PDF(8)

Abstract:
Interaction of procainamide hydrochloride (PAH) with human serum albumin (HSA) is of great significance in understanding the pharmacokinetic and pharmacodynamic mechanisms of the drug. Multi-spectroscopic techniques were used to investigate the binding mode of PAH to HSA and results revealed the presence of static type of quenching mechanism. The number of binding sites, binding constants and thermodynamic parameters were calculated. The results showed a spontaneous binding of PAH to HSA and hydrophobic interactions played a major role. In addition, the distance between PAH and the Trp–214 was estimated employing the F?rster's theory. Site marker competitive experiments indicated that the binding of PAH to HSA primarily took place in subdomain ⅡA (Sudlow's site I). The influence of interference of some common metal ions on the binding of PAH to HSA was studied. Synchronous fluorescence spectra (SFS), 3D fluorescence spectra and circular dichroism (CD) results indicated the conformational changes in the structure of HSA.

Square wave voltammetric quantification of folic acid, uric acid and ascorbic acid in biological matrix

Majid Arvand, Akram Pourhabib, Masoud Giahi

2017, 7(2): 110-117.

Abstract(141) PDF(7)

Abstract:
Nowadays, modified electrodes with metal nanoparticles have appeared as an alternative for the electroanalysis of various compounds. In this study, gold nanoparticles (GNPs) were chosen as interesting metal nanoparticles for modifying carbon paste electrode (CPE). GNPs and the gold nanoparticles-modified carbon paste electrode (GNPs/CPE) were characterized by UV–Vis spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). GNPs/CPE as a simple and sensitive electrode was used to study three important biological molecules:folic acid (FA), uric acid (UA) and ascorbic acid (AA). Square wave voltammetry (SWV) was used as an accurate technique for quantitative measurements. A good linear relation was observed between anodic peak current (ipa) and FA (5.2 × 10?6–2.5 × 10?5 M), UA (1.2 × 10?6–2.1 × 10?5 M) and AA (1.2 × 10?6–2.5 × 10?5 M) concentrations in simultaneous determination of these molecules.

Degradation kinetics of larotaxel and identification of its degradation products in alkaline condition

Xiaoming Liang, Zhenzhen Liu, Huiyan Shi, Yuanyuan Zhang, Shixiao Wang, Kaishun Bi, Xiaohui Chen

2017, 7(2): 118-122.

Abstract(105) PDF(3)

Abstract:
Larotaxel, a new taxane compound prepared by partial synthesis from 10-deacetyl baccatin Ⅲ, is active against tumors. In this research, a selective LC–MS method was developed and validated for the study of degradation kinetics of larotaxel, which was carried out in aqueous solutions with different pH (1.5, 3.0, 5.0, 6.5, 7.4, 9.0, 10 and 11.0) and temperature (0, 25, 37 and 45 °C). The linear range was 0.5–25μg/mL, the intra-and inter-day precisions were less than 7.0%, and accuracy ranged from 97.4–104.5% for each analyte. The observed rate obtained by measuring the remaining intact larotaxel was shown to follow first-order kinetics. The activation energies for degradation were 126.7 and 87.01 kJ/mol at pH 1.5 and 11, respectively. Although larotaxel was stable in pH 5, 6.5 and 7.4 buffers at 37 °C for 24 h during our study, increasing or decreasing the pH of the solutions would decrease its stabilities. Moreover, three main degradation products in alkaline condition were separated by HPLC and identified by Q–TOF–MS. The three degradation products were confirmed as 10-deacetyl larotaxel, 7, 8-cyclopropyl baccatin Ⅲ and 10-deacetyl-7, 8-cyclopropyl baccatin Ⅲ.

Anti-atherosclerotic activity of root bark of Premna integrifolia Linn. in high fat diet induced atherosclerosis model rats

Chitra Subramani, Arivukkodi Rajakkannu, Arunadevi Rathinam, Sudesh Gaidhani, Ilavarasan Raju, Dhiman Vaidya Kartar Singh

2017, 7(2): 123-128.

Abstract(172) PDF(13)

Abstract:
Premna integrifolia Linn. is a medicinal plant used in"Dhasamula"drug preparation of Ayurvedic systems of medicine in the treatment of various ailments like bronchitis, dyspepsia, liver disorders, piles, constipation, hyperlipidemia and fever. The anti-atherosclerotic activity of hydroalcoholic extract (HAE) of root bark of P. integrifolia was evaluated in high fat diet induced atherosclerosis rats. Sixty Wistar rats were divided into six groups:the first group served as control, the second group was fed with high fat diet and the other three groups were fed with high fat diet along with various concentrations of HAE and the last group was treated with atorvastatin for 30 days. Lipid and lipoprotein profile, atherogenic index, and cardiac markers and histopathological evaluation of aorta were determined in high fat diet induced atherosclerosis rats. HAE of P. integrifolia produced a significant and dose-dependent anti-atherosclerotic activity in terms of reduction in lipids and lipoprotein profile, atherogenic index, HMG-CoA reductase activity, marker enzymes such as lactate dehydrogenase (LDH), creatine phosphokinase (CPK), aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP), alteration in collagen and calcium contents, mild mineralization and focal rupture of intima and media of aorta was noticed in treated groups as compared to the control. The results suggested that anti-atherosclerotic activity of HAE of P. integrifolia Linn. was due to its modulatory activity on metabolic pathway of lipid. The results contribute to the validation of the traditional use of Agnimantha in high fat diet induced atherosclerosis rats.

A stability-indicating high performance liquid chromatography method to determine apocynin in nanoparticles

Juliana Kovalczuk de Oliveira, Débora Fernanda Veres Ronik, Jociani Ascari, Rubiana Mara Mainardes, Najeh Maissar Khalil

2017, 7(2): 129-133.

Abstract(211) PDF(3)

Abstract:
In this study, we developed and validated a fast, specific, sensitive, precise and stability-indicating high performance liquid chromatography (HPLC) method to determine the drug apocynin in bovine serum albumin (BSA) nanoparticles. Chromatographic analyses were performed on an RP C18 column and using a photodiode array detector at a wavelength of 276 nm. Mobile phase consisted of a mixture of acetonitrile and 1%acetic acid (60:40, v/v), and it was eluted isocratically at a flow rate of 0.8 mL/min. The retention time of apocynin chromatographic peak was 1.65 min. The method was linear, precise, accurate and specific in the range of 5–100μg/mL. The intra-and inter-day precisions presented relative standard deviation (RSD) values lower than 2%. The method was robust regarding changes in mobile phase proportion, but not for flow rate. Limits of detection and quantitation were 78 ng/mL and 238 ng/mL, respectively. Apocynin was exposed to acid and alkali hydrolysis, oxidation and visible light. The drug suffered mild degradation under acid and oxidation conditions and great degradation under alkali conditions. Light exposure did not degrade the drug. The method was successfully applied to determine the encapsulation efficiency of apocynin in BSA nanoparticles.

Development and validation of a stability-indicating RP–HPLC method for estimation of atazanavir sulfate in bulk

S. Dey, S. Subhasis Patro, N. Suresh Babu, P.N. Murthy, S.K. Panda

2017, 7(2): 134-140.

Abstract(225) PDF(9)

Abstract:
A stability-indicating reverse phase–high performance liquid chromatography (RP–HPLC) method was developed and validated for the determination of atazanavir sulfate in tablet dosage forms using C18 column Phenomenix (250 mm×4.6 mm, 5μm) with a mobile phase consisting of 900 mL of HPLC grade methanol and 100 mL of water of HPLC grade. The pH was adjusted to 3.55 with acetic acid. The mobile phase was sonicated for 10 min and filtered through a 0.45μm membrane filter at a flow rate of 0.5 mL/min. The detection was carried out at 249 nm and retention time of atazanavir sulfate was found to be 8.323 min. Linearity was observed from 10 to 90μg/mL (coefficient of determination R2 was 0.999) with equation, y=23.427x+37.732. Atazanavir sulfate was subjected to stress conditions including acidic, alkaline, oxidation, photolysis and thermal degradation, and the results showed that it was more sensitive towards acidic degradation. The method was validated as per ICH guidelines.

2017 Vol. 7, No. 2