International Journal of Chemical and Analytical Science最新文献

Emergence of drug resistance is a serious problem in controlling fungal infectious diseases, thus there is a need to look for new drugs from various sources to combat with the problem. Many plants are used in traditional medicine as therapeutic agents which need scientific validation. In the present investigation, Eclipta prostrata L. a known medicinal plant of tropics is evaluated for antifungal potential against species of human infectious Microsporum and Trichophyton following CLSI protocols. Of the five extracts significant activity was observed in petroleum ether extract with a MIC of 0.15 mg mL⁻¹ against all the test fungi. Attempts to isolate the active principle by TLC revealed 5 bands, but none of the bands showed activity in bioautography, suggesting the synergistic effect. Further work is in progress to identify the combination of molecules responsible for the synergism.

Aim

In this work we studied four azo dyes which are proposed for synthetic colorants in foods applications and named L₁: Sunset Yellow, E110, L₂: Tartrazin, E102, L₃: Amaranth, E123, L₄: Red Ponceau 4R, E124. In addition, electron density analysis has been carried out to highlight the possible strengths of interaction of these four azo dyes with metal ions.

Materials and methods

Density Functional Theory (DFT) was utilized, using the B3LYP functional and the 6-31G(d) basis set. This level of calculation was used to find the optimized molecular structure and to predict the molecular orbitals energies, dipole moment, Fukui function values ${f^{-}}_k$, locals nucleophilicity indexes N_k and the chemical reactivity parameters that arise from Conceptual DFT. Also, the steric energies values from the four complexes were calculated with the EMO program using MM2 method.

Results

Complexes forms with mercury are easier to form and more stable than copper. These show that the mercury intoxication is faster than the copper, knowing that mercury is toxic even with low dose. For that, the men who carry amalgams, we advise may be avoid to eat food and drugs which contain azo dyes because there exists a high trend between these azo dyes and the metal ions which released by the amalgams.

Background/Objective

A direct, accurate, precise, reproducible and cost-time efficient approach for calibration of HPLC using mass spectrometer as detector has been described which simulates the routine analysis in bioanalytical laboratories.

Methods

Injector position check and injection volume repeatability test for the calibration of autosampler; and pump flow rate accuracy test for the calibration of pumps were illustrated using direct weighing method. Carryover test, pump repeatability test, linearity and precision were carried out for holistic (overall system) calibration of the instrument using a sensitive high throughput LC–MS/MS pre-validated method.

Results/Conclusion

The results of calibration experiments for individual modules suggested that pumps are yielding accurate flow rate, autosampler is aspirating the correct injection volume irrespective to position or volume, and column oven and autosampler chambers are maintaining steady temperatures. Holistic calibration verified the accuracy, precision, repeatability and reproducibility of the instrument with insignificant carryover.

Aim

In recent years oxidative stress was found to play the significant role in causing various diseases, including neurodegenerative disorders like, Alzheimer's. Lack of antioxidant mechanisms is the major cause for increased oxidative stress. Flavonoids and phenolic compounds from herbs are going to play efficient role in scavenging the free radicals responsible for oxidative stress. Present investigation deals with the free radical scavenging activity of Leucas species in relation to neurodegenerative disorder.

Methods

Ethanolic extract of selected plant was estimated for phenolic and flavonoids contents and then screened for free radical scavenging activity with various oxygen radicals. The extract was further tested invitro for acetylcholinesterase inhibitory activity along with cytotoxic activity.

Results

The extract was found to contain 42.28 ± 8.88 RE/g of flavonoids and 38.624 ± 14.171 GAE/g of phenolic compounds along with significant free radical scavenging activity in comparison with the standard Quercetin. The extract was found to be non cytotoxic with no inhibitory activity on acetylcholinesterase.

Conclusion

Inspite of its inability to inhibit acetylcholinesterase, the selected plant extract can be safely used for treating neurodegenerative disorders like Alzheimer's because of its effective free radical scavenging activity.

An asymmetric synthesis of the piperidine alkaloid (−)-sedridine isolated from Sedum acre, has been accomplished starting from S-malic acid as the chiral precursor employing Maruoka Keck allylation, azide nucleophillic substitution and ring closing metathesis as the key steps.

Objective

To develop a simple, novel, sensitive, precise and specific RP-HPLC method for the determination of Tapentadol hydrochloride in bulk and its tablet dosage forms.

Methods

The chromatographic separation was achieved on C18 Licrosphere column (150 mm × 4.6 mm inner diameter, 5 μm particle size) as a stationary phase using Methanol: 0.1 mM Dipotassium Phosphate buffer (pH 4, adjusted with ortho phosphoric acid) as mobile phase at detection wavelength 280 nm in isocratic mode at a flow rate of 1 ml/min.

Results

The calibration curve for Tapentadol hydrochloride was linear from 75 to 450 μg/ml. The correlation coefficient (r²) value was found to be 0.9994. Precision study showed % CV value less than 2% in all selected concentrations. The % recoveries of Tapentadol hydrochloride are in the range of 99.96–100.01%. The limit of detection and limit of quantification for Tapentadol hydrochloride were found to be 0.25 μg/ml and 0.75 μg/ml respectively.

Conclusion

The developed method has good sensitivity, reproducibility and specificity for the determination of Tapentadol hydrochloride in bulk and its tablet dosage forms. This method was simple, fast, accurate, and precise. Hence this method was validated and found to be suitable for determining the purity of Tapentadol hydrochloride in bulk drugs and pharmaceutical formulations. The proposed validated method was successfully used for the quantitative analysis of commercially available dosage form.

A rapid, sensitive and specific method based on high performance liquid chromatography (HPLC) has been developed for the simultaneous determination of amitriptyline hydrochloride and Sildenafil citrate in the blood of rats. Sample preparation involved liquid–liquid extraction with n-hexane after alkalified with 0.5 M NaOH. Chromatographic separation was performed on XDB C-18 column with particle size of 5 μm (150 × 4.6 mm) with mobile phase acetonitrile and 20 mM KH₂PO₄ buffer, pH = 3 using flow rate 1.5 ml/min. Calibration curves were linear within the ranges of 0.25–50 and 0.1–50 μg/ml for amitriptyline hydrochloride and Sildenafil citrate, respectively. This method was successfully applied to the pharmacokinetic study in rats after oral administration of amitriptyline hydrochloride and Sildenafil citrate for 24 h.

Background/objectives

The importance of food fibers has led to the development of a large and potential market for fiber-rich products and ingredients and in recent years. There is a trend to find new sources of dietary fiber that can be used in the food industry. Resistant maltodextrin is a water soluble fiber and short chain polymer of glucose that are resistant to digestion in the human digestive system.

Method

As per the AOAC method for determination of total dietary fiber the estimation of low molecular weight resistant maltodextrin involves many tedious steps which make it lengthy & time consuming.

Results

Being colorless, tasteless and of low calorific value, resistant maltodextrin qualifies to be a perfect material to used for dietary fiber fortification purposes. Keeping in view the time of analysis, possibility of analytical errors in multiple processing steps & cost of analysis, a simple procedure for determination of resistant maltodextrin has been developed and validate using High performance liquid chromatograph with refractive index detector (HPLC-RID) in fortified fruit juices in 0range citrus Punch.

Conclusion

For the confirmation of newly developed analytical method several samples of juices were also analyzed. The method given specifically measures resistant maltodextrin.