Functionalized nanoparticles based solid-phase membrane micro-tip extraction and high-performance liquid chromatography analyses of vitamin B complex in human plasma.

Iron nanoparticles were prepared by a green method following functionalization using 1-butyl-3-methylimidazolium bromide. 1-Butyl-3-methylimidazole iron nanoparticles were characterized using FTIR spectroscopy, energy dispersive X-ray fluorescence, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The nanoparticles were used in solid-phase membrane micro-tip extraction to separate vitamin B complex from plasma before high-performance liquid chromatography. The optimum conditions obtained were sorbent (15 mg), agitation time (30 min), pH (9.0), desorbing solvent [water (5 mL) + methanol (5 mL) + sodium hydroxide (0.1 N) + acetic acid (d = 1.05 kg/L, pH 5.5), desorbing volume (10 mL) and desorption time (30 min). The percentage recoveries of all the eight vitamin B complex were from 60 to 83%. A high-performance liquid chromatography method was developed using a PhE column (250 × 4.6 mm, 5.0 µm) and water/acetonitrile (95:5, v/v; pH 4.0 with 0.1% formic acid) mobile phase. The flow rate was 1.0 mL/min with detection at 270 and 210 nm. The values of the capacity, separation and resolution factor were 0.57-39.47, 1.12-6.00 and 1.84-26.26, respectively. The developed sample preparation and chromatographic methods were fast, selective, inexpensive, economic and reproducible. The developed method can be applied for analyzing these drugs in biological and environmental matrices.

Development and validation of high-performance liquid chromatography and high-performance thin-layer chromatography methods for the quantification of khellin in Ammi visnaga seed.

OBJECTIVE: The present study was used to design simple, accurate and sensitive reversed phase-high-performance liquid chromatography RP-HPLC and high-performance thin-layer chromatography (HPTLC) methods for the development of quantification of khellin present in the seeds of Ammi visnaga. MATERIALS AND METHODS: RP-HPLC analysis was performed on a C18 column with methanol: Water (75: 25, v/v) as a mobile phase. The HPTLC method involved densitometric evaluation of khellin after resolving it on silica gel plate using ethyl acetate: Toluene: Formic acid (5.5:4.0:0.5, v/v/v) as a mobile phase. RESULTS: The developed HPLC and HPTLC methods were validated for precision (interday, intraday and intersystem), robustness and accuracy, limit of detection and limit of quantification. The relationship between the concentration of standard solutions and the peak response was linear in both HPLC and HPTLC methods with the concentration range of 10-80 µg/mL in HPLC and 25-1,000 ng/spot in HPTLC for khellin. The % relative standard deviation values for method precision was found to be 0.63-1.97%, 0.62-2.05% in HPLC and HPTLC for khellin respectively. Accuracy of the method was checked by recovery studies conducted at three different concentration levels and the average percentage recovery was found to be 100.53% in HPLC and 100.08% in HPTLC for khellin. CONCLUSIONS: The developed HPLC and HPTLC methods for the quantification of khellin were found simple, precise, specific, sensitive and accurate which can be used for routine analysis and quality control of A. visnaga and several formulations containing it as an ingredient.

Analyses of anticancer drugs by capillary electrophoresis: a review.

Capillary electrophoresis is a fast, inexpensive and low detection limit technique for the analysis of anticancer drugs. It has been used to analyze various anticancer drugs in biological samples, pharmaceutical preparations and environmental matrices. It has also been used to detect various cancer biomarkers in cancer patients. The present article describes the state-of-the art of capillary electrophoresis for the analyses of anticancer drugs. Various drugs discussed belong to several groups such as antimitotic agents, nucleoside analogs, antibiotics, topoisomerase inhibitors and DNA intercalating agents. In addition, efforts have also been made to discuss sample preparation, applications of capillary electrophoresis in genomic research, optimization and future perspectives.

Curcumin-I Knoevenagel's condensates and their Schiff's bases as anticancer agents: synthesis, pharmacological and simulation studies.

Pyrazolealdehydes (4a-d), Knoevenagel's condensates (5a-d) and Schiff's bases (6a-d) of curcumin-I were synthesized, purified and characterized. Hemolysis assays, cell line activities, DNA bindings and docking studies were carried out. These compounds were lesser hemolytic than standard drug doxorubicin. Minimum cell viability (MCF-7; wild) observed was 59% (1.0 µg/mL) whereas the DNA binding constants ranged from 1.4×10(3) to 8.1×10(5) M(-1). The docking energies varied from -7.30 to -13.4 kcal/mol. It has been observed that DNA-compound adducts were stabilized by three governing forces (Van der Wall's, H-bonding and electrostatic attractions). It has also been observed that compounds 4a-d preferred to enter minor groove while 5a-d and 6a-d interacted with major grooves of DNA. The anticancer activities of the reported compounds might be due to their interactions with DNA. These results indicated the bright future of the reported compounds as anticancer agents.

Glutamic acid and its derivatives: candidates for rational design of anticancer drugs.

Throughout the history of human civilizations, cancer has been a major health problem. Its treatment has been interesting but challenging to scientists. Glutamic acid and its derivative glutamine are known to play interesting roles in cancer genesis, hence, it was realized that structurally variant glutamic acid derivatives may be designed and developed and, might be having antagonistic effects on cancer. The present article describes the state-of-art of glutamic acid and its derivatives as anticancer agents. Attempts have been made to explore the effectivity of drug-delivery systems based on glutamic acid for the delivery of anticancer drugs. Moreover, efforts have also been made to discuss the mechanism of action of glutamic acid derivatives as anticancer agents, clinical applications of glutamic acid derivatives, as well as recent developments and future perspectives of glutamic acid drug development have also been discussed.

Recent developments in HPLC analysis of ß-blockers in biological samples.

ß-Adrenergic blockers represent a very important class of drugs that are used worldwide for treating various cardiac diseases. The present article describes the state-of-the art of analyses of ß-adrenergic blockers using high-performance liquid chromatography (HPLC). Sample preparation techniques such as liquid-liquid extraction, solid-phase extraction and solid-phase microextraction have been discussed, which are essential prior to HPLC analysis. Additionally, applications of liquid chromatography coupled with tandem mass spectrometry are included. HPLC methods have been reported to include 0.6-26 min as the run times and 0.01 ng/mL to 25 µg/mL as detection limits. The most commonly used columns were C18 with various buffers as the mobile phases, along with various organic modifiers. The optimization of HPLC conditions has been discussed. It has been observed that the reported methods are quite satisfactory for the analyses of ß-adrenergic blockers in biological samples. Future perspectives in the hyphenation of solid-phase microextraction-nano-liquid chromatography-tandem mass spectrometry have also been highlighted to achieve detections at nanogram and picogram levels. The present article is very useful for academicians, scientists, drug and pharmaceutical personnel and government regulatory authorities.

Synthesis, DNA binding, hemolysis assays and anticancer studies of copper(II), nickel(II) and iron(III) complexes of a pyrazoline-based ligand.

BACKGROUND: Over the last few decades, metal-based drugs, particularly cisplatin and its analogs have been used for the treatment of various cancers. Currently, scientists are developing other metal complexes as anticancer agents to eliminate the toxicity associated with platinum drugs. RESULTS: Claisen-Schmidt condensation was used to synthesize the pyrazoline-based ligand; (5-(4-chlorophenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide), followed by the synthesis of its complexes with copper(II), nickel(II) and iron(III) metal ions. DNA binding and in silico studies indicated quite good binding with DNA; requirements for good anticancer drugs. CONCLUSION: DNA binding constants for ligand, copper, nickel and iron complexes were 1.42 × 10(4), 3.16 × 10(4), 5.82 × 10(5) and 6.72 × 10(5) M(-1), respectively, indicating strong binding with DNA. All the reported compounds were slightly hemolytic towards rabbit red blood corpuscles and exhibited moderate activities against MCF-7 cancer cell lines.

Platinum compounds: a hope for future cancer chemotherapy.

The discovery of cis-platin and its second and third generation analogues created a hope in cancer chemotherapy. Cis-platin and its second generation analogue carboplatin have been used for the treatment of some cancers from a long time. The third generation analogues have superior anti-cancer profiles for curing a few cancers. Unfortunately, certain side effects such as renal impairment, neurotoxicity and ototoxicity etc. are associated with these drugs. But, combination therapy makes these analogues more effective with fewer side effects. In addition, the results of some ongoing clinical trials will make the safety profile clear in near future. The present article describes the current status of cis-platin and its analogues in cancer chemotherapy. In addition, special emphasis has been made on cis-platin discovery, development of second (carboplatin, oxaliplatin, nedaplatin) and third (lobaplatin, heptalatin) generation analogues, comparison of their chemotherapies, mechanism of action, therapeutic status, recent developments and chronology. Moreover, attempts have been made to describe the future perspectives of these drugs in the cancer treatment.

Syntheses, DNA binding and anticancer profiles of L-glutamic acid ligand and its copper(II) and ruthenium(III) complexes.

A new multidentate ligand (L) has been synthesized by the controlled condensation of L-glutamic acid with formaldehyde and ethylenediamine. Cu(II) and Ru(III) metal ion complexes of the synthesized ligand have also been prepared. The ligand and the metal complexes were purified by chromatography and characterized by spectroscopy and other techniques. Molar conductance measurements suggested ionic nature of the complexes. The ligand and the complexes are soluble in water with quite good stabilities; essential requirements for effective anticancer drugs. DNA binding constants (Kbs) for copper and ruthenium complexes were 1.8 x 103 and 2.6 x 103 M-1 while their Ksv values were 7.9 x 103, and 7.3 x 103; revealing strong binding of these complexes with DNA. Hemolytic assays of the reported compounds indicated their significantly less toxicity to RBCs than the standard anticancer drug letrazole. Anticancer profiles of all the compounds were determined on HepG2, HT-29, MDA-MB-231 and HeLa human cancer cell lines. All the compounds have quite good activities on HeLa cell lines but the best results were of CuL on HepG2, HT-29 and MDA-MB-231 cell lines.

Synthesis and synergistic antifungal activities of a pyrazoline based ligand and its copper(II) and nickel(II) complexes with conventional antifungals.

A pyrazoline based ligand; (5-(4-chlorophenyl)-3-phenyl-4, 5-dihydro-1H-pyrazole-1-carbothioamide) has been synthesized by Claisen-Schmidt condensation of acetophenone with p-chlorobenzaldehyde, followed by sodium hydroxide assisted cyclization of the resulting chalcone with thiosemicarbazide. Metal ion complexes of the synthesized ligand were prepared with Cu(II) and Ni(II) metal ions, separately and respectively. Ligand and the metal complexes were characterized by elemental analysis, FT-IR, UV-Vis, (1)HNMR, ESI-MS and (13)CNMR spectroscopic techniques. Molar conductance measurements in DMSO suggested non-electrolytic nature of the complexes. Tetragonally distorted octahedral geometry for copper and octahedral geometry for the nickel complexes was proposed on the basis of UV-Vis spectroscopic studies and magnetic moment measurements. The complexes were investigated for their ability to kill human fungal pathogen Candida by determining MICs (Minimum inhibitory concentrations), inhibition in solid media and ability to produce a possible synergism with conventional most clinically practiced antifungals by disc diffusion assay and FICI (fractional inhibitory concentration index).

Enantiomeric resolution of ibuprofen and flurbiprofen in human plasma by SPE-chiral HPLC methods.

Chiral analysis of profens in human plasma is an important area of research due to different pharmaceutical activities of their enantiomers. The solid phase extraction of ibuprofen and flurbiprofen from human plasma was carried out on C18 cartridges by using phosphate buffer (50 mM, pH 6.0) followed by elution with methanol. Chiral-HPLC was performed on AmyCoat RP (150 mm x 46 mm, 3 µm particle size) column by using different combinations of water-acetonitrile-trifluoro acetic acid at 1.5 mLmin-1 flow rate. The detection was achieved at 236 and 254 nm for ibuprofen and flurbiprofen, respectively with 27±1°C as working temperature. The chromatographic parameters i.e. retention (k), separation (α) and resolution (Rs) factors ranged from 4.54-14.42, 1.10-1.30 and 1.01-1.49, respectively. The binding differences of enantiomers of ibuprofen and flurbiprofen were 4.4 and 5.2, respectively. These values suggest that S-(+)- enantiomer of flurbiprofen is more active than ibuprofen due to low enantiomeric difference of the later drug. The developed SPE-Chiral HPLC methods were validated, which are selective, efficient and reproducible.

Simultaneous HPTLC determination of strychnine and brucine in strychnos nux-vomica seed.

OBJECTIVE: A simple, sensitive, and specific thin layer chromatography (TLC) densitometry method has been developed for the simultaneous quantification of strychnine and brucine in the seeds of Strychnos nux-vomica. MATERIALS AND METHODS: The method involved simultaneous estimation of strychnine and brucine after resolving it by high performance TLC (HPTLC) on silica gel plate with chloroform-methanol-formic acid (8.5:1.5:0.4 v/v/v) as the mobile phase. RESULTS: The method was validated as per the ICH guidelines for precision (interday, intraday, intersystem), robustness, accuracy, limit of detection, and limit of quantitation. The relationship between the concentration of standard solutions and the peak response was linear within the concentration range of 50-1000 ng/spot for strychnine and 100-1000 ng/spot for brucine. The method precision was found to be 0.58-2.47 (% relative standard deviation [RSD]) and 0.36-2.22 (% RSD) for strychnine and brucine, respectively. Accuracy of the method was checked by recovery studies conducted at three different concentration levels and the average percentage recovery was found to be 100.75% for strychnine and 100.52% for brucine, respectively. CONCLUSIONS: The HPTLC method for the simultaneous quantification of strychnine and brucine was found to be simple, precise, specific, sensitive, and accurate and can be used for routine analysis and quality control of raw material of S. nux-vomica and several unani and ayurvedic formulations containing this as an ingredient.

Chiral analyses at nano-scale.

Nano scale chiral separation is essential and has become the demand of current century in drugs development, proteomic, genomic and environmental sciences. Some drugs remain in our body tissues for several weeks at nano scale, which are out of the domain of detection by conventional analytical methods. Similarly, the analyses and detection of xenobiotics; present at nano or low levels; are essential for our health. The present review describes the state-of-art of nano scale chiral separations by nano liquid chromatography (NLC) and nano capillary electrophoresis (NCE). The optimization strategies of chiral separations have been also discussed. Furthermore, efforts were made to discuss the mechanisms of chiral separations in NLC and NCE.

Chiral separations of some beta-adrenergic agonists and antagonists on AmyCoat column by HPLC.

Sixteen beta-adrenergic antagonists namely acebutalol, alprenolol, atenolol, bisoprolol, bopindolol, bufurolol, carazolol, celiprolol, indenolol, metaprolol, nebivolol, oxprenolol, practolol, propranolol, tertalol, and timolol, and two beta-adrenergic agonists namely cimeterol and clenbuterol were resolved on AmyCoat (150 x 46 mm, 3 microm size of silica particle) by using (85:15:0.1, v/v/v), (90:10:0.1, v/v/v), and (95:05:0.1, v/v/v) combinations of n-heptane, ethanol, and diethylamine solvents, respectively. The flow rates used were 0.5, 1.0, 2.0, and 3.0 ml/min with detection at 225 nm. The values of capacity, separation, and resolution factors ranged from 0.38 to 19.70, 1.08-2.33, and 1.0 and 4.50, respectively. The maximum and minimum resolutions were achieved for celiprolol and bufurolol, respectively. The chiral recognition mechanisms were also discussed. The values of validation parameters were calculated.

Nanoparticles of cationic chimeric peptide and sodium polyacrylate exhibit striking antinociception activity at lower dose.

The current study investigates the performance of polyelectrolyte complexes based nanoparticles in improving the antinociceptive activity of cationic chimeric peptide-YFa at lower dose. Size, Zeta potential and morphology of the nanoparticles were determined. Size of the nanoparticles decreases and zeta potential increases with concomitant increase in charge ratio (Z(+/-)). The nanoparticles at Z(+/-)12 are spherical with 70+/-7 nm diameter in AFM and displayed positive surface charge and similar sizes (83+/-8 nm) by Zetasizer. The nanoparticles of Z(+/-) 12 are used in this study. Cytotoxicity by MTT assay on three different mammalian cell lines (liver, neuronal and kidney) revealed lower toxicity of nanoparticles. Hematological parameters were also not affected by nanoparticles compared to normal counts of water treated control group. Nanoparticles containing 10 mg/kg YFa produced increased antinociception, approximately 36%, in tail-flick latency test in mice, whereas the neat peptide at the same concentration did not show any antinociception activity. This enhancement in activity is attributed to the nanoparticle associated protection of peptide from proteolytic degradation. In vitro peptide release study in plasma also supported the antinociception profile of nanoparticles. Thus, our results suggest of a potential nanoparticle delivery system for cationic peptide drug candidates for improving their stability and bioavailability.

Lack of tolerance and morphine-induced cross-tolerance to the analgesia of chimeric peptide of Met-enkephalin and FMRFa.

Chimeric peptide of Met-enkephalin and FMRFa (YGGFMKKKFMRFa-YFa), a kappa-opioid receptor specific peptide, did not induce tolerance and cross-tolerance effects to its analgesic action on day 5 after pretreatment with either YFa or morphine for 4 days. However, pretreatment with YFa for 4 days led to the development of cross-tolerance to the analgesic effects of morphine and also 4 days of pretreatment of morphine resulted in the expression of tolerance to its own analgesic effects. Similar expression of tolerance and cross-tolerance were also observed when YFa was compared with the kappa receptor agonist peptide dynorphin A(1-13) [DynA(1-13)]. Cross-tolerance effects between YFa and DynA(1-13) analgesia were also not observed on day 5. Interestingly, when YFa and DynA(1-13) were tested for their analgesic effects for 5 days, reduction in analgesia on day 3 was observed in case of DynA(1-13) whereas YFa maintained its analgesia for 5 days. Thus, chimeric peptide YFa may serve as a useful probe to understand pain modulation and expression of tolerance and cross-tolerance behavior with other opioids.

Supramolecular chiro-biomedical assays and enantioselective HPLC analyses for evaluation of profens as non-steroidal anti-inflammatory drugs, potential anticancer agents and common xenobiotics.

The permanent world-wide increase in therapeutic administration of racemic profens as easy available non-prescribed analgesic drugs and a common first-choice anti-inflammatory agents was recently linked with renewed interest in their beneficial use, also as enantiopure formulations, to treat and/or prevent a variety of human malignancies including its four major types as colorectal, breast, lung, and prostate cancer. This underlies the continuous need of selecting perfectly suited chiral separation methods of profens capable to determine nanolevels of a distomer in presence of the eutomer in a variety of complex biological and environmental media. Thus, current improvements for direct enantiomeric separations of profens by well defined supramolecular-based chiral HPLC and recently developed monolithic, combinatorial, bimodal and polymeric chiral stationary phases employing a modern supramolecular chirality concepts has been outlined in this review. The use of diverse supramolecular approaches for chiral HPLC as an easy accessible tool enabling fast development of nanoscale enantioselective, high-throughput and gradient screening procedures for in situ monitoring of stereoselective ADME properties of profens in range of anticancer drug discovery technologies has been also addressed.

Synthesis and in vitro antibacterial activity of new steroidal thiosemicarbazone derivatives.

We investigated the antibacterial activity of some new steroidal thiosemicarbazone derivatives, prepared from the reaction of cholest-5-en-7-one with thiosemicarbazides, in ethanol in the presence of a few drops of HCl at 80 degrees C in high yield. All the compounds have been characterized by means of elemental analyses, IR, 1H NMR and mass spectroscopic data, to find an effective antibacterial agent. The antibacterial activity was first tested in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria, and then the minimum inhibitory concentration (MIC) of compounds was determined. The results showed that the steroidal thiosemicarbazones derivatives inhibit growth of both types of the bacteria (Gram-positive and Gram-negative). The acetoxy and chloro derivatives of cyclopentyl and cyclohexyl amine thiosemicarbazones were found to have more antibacterial activity than the other derivatives.

Synthesis, structure elucidation and antibacterial evaluation of new steroidal -5-en-7-thiazoloquinoxaline derivatives.

Some heterocyclic systems namely cholest-5-en-7-thiazolo[4,5-b]quinoxaline-2-yl-hydrazone] were synthesized by the reaction of cholest-5-en-7-one-thiosemicarbazone with 2,3-dichloroquinoxaline at 80 degrees C in high yield. The thiosemicarbazone derivatives were obtained by the condensation of the thiosemicarbazide with steroidal ketones. All the compounds have been characterized by means of elemental analyses, IR, 1H NMR and mass spectroscopic data. The in vitro antibacterial activity was evaluated by disk diffusion method and then the minimum inhibitory concentration (MIC) of compounds was determined against the culture of Escherichia coli. The results were compared with the standard drug chloramphenicol. The results showed that compounds 7 and 8 are better antibacterial agents as compared to chloramphenicol.

Synthesis, characterization and in vitro antibacterial activity of thiourea and urea derivatives of steroids.

Some heterocyclic systems namely stigmest-6-en-7, 5alpha thiourea and stigmest-6-en-7, 5alpha urea derivatives of steroids were synthesized by the reaction of stigmest-5-en-7 one with thiourea/urea in the presence of a few drops of conc. HCl at 80 degrees C in high yield. All the compounds have been characterized by means of elemental analyses, IR, 1H NMR, 13C NMR and mass spectroscopic data. The antibacterial activity was first tested in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria, and then the minimum inhibitory concentration (MIC) of compounds were determined. The results showed that steroidal thiourea derivatives inhibit growth as compared to steroidal urea derivatives of both type of the bacteria (Gram-positive and Gram-negative). Compounds 3 and 4 are better antibacterial agents as compared to standard drug chloramphenicol.