Mosquitocidal activities of Chenopodium botrys whole plant n-hexane extract against Culex quinquefasciatus

This research aimed to investigate various mosquitocidal activities of Chenopodium botrys whole- plant n-hexane extract against Culex quinquefasciatus. The extract showed remarkable larvicidal, pupicidal, adulticidal, oviposition deterrent and adult emergence inhibitory activities against Cx. quinquefasciatus. During the larvicidal and pupicidal activities, the 24-hour lethal concentration (LC50) of extract against 2nd instar larvae, 4th instar larvae and pupae were 324.6, 495.6 and 950.8 ppm, respectively. During the CDC (Centers for Disease Control and Prevention) bottle bioassay for adulticidal activity, the median knockdown times (KDT50) at 1.25% concentration was 123.4 minutes. During the filter paper impregnation bioassay for adulticidal activity, the KDT50 value at 0.138 mg/cm2 concentration was 48.6 minutes. The extract was fractionated into 14 fractions through silica gel column chromatography which were then combined into six fractions on the basis of similar retention factor (Rf) value. These fractions were screened for adulticidal activity by applying CDC bottle bioassay. The fraction obtained through 60:40 to 50:50% n-hexanes-chloroform mobile phase with 0.5 Rf value showed 100% adulticidal activity at 0.2% concentration. During oviposition deterrent activity, the highest concentration (1000 ppm) showed 71.3 ± 4.4% effective repellence and 0.6 ± 0.1 oviposition activity index. During adult emergence inhibition activity, the median emergence inhibition (EI50) value was 312.3 ppm. From the outcome of the present investigation, it is concluded that the n-hexane extract of C. botrys whole- plant possesses strong larvicidal, pupicidal, adulticidal, oviposition deterrent and adult emergence inhibitory activities against Cx. quinquefasciatus.

Study of anaesthetical activity of alkoxyphenylcarbamic acid esters using statistical methods

Anaesthetical activity of 113 morpholinoethyl-, piperidinoethyl-, piperidinopropyl- and azepanoethyl- ester derivatives of alkoxyphenylcarbamic acid was characterized by several chemometrical techniques. The surface anaesthetical activity, A, and the infiltration anaesthetical activity, B, were correlated to lipophilicity, (expressed by the logarithm of the HPLC retention factor, log k), the length of the side alkoxy chain (represented by the number n of carbon atoms), molar mass M as well as the ester type. Principal component analysis and cluster analysis were used for predicting both types of the anaesthetic activity of the alkoxyphenylcarbamic acid esters.

IN SILICO MODELLING, SYNTHESIS, AND ANTI-DIABETIC EVALUATION OF BENZOTHIAZOLE SUBSTITUTED OXADIAZOLE DERIVATIVES

Objective: The study contemplates in silico modeling, synthesis and in-vitro anti-diabetic evaluation of benzothiazole substituted oxadiazole derivatives. [{5-[(1, 3-benzothiazol-2-ylsulfanyl) methyl]-1, 3, 4-oxadiazol-2-yl} sulfanyl) methyl] derivatives were synthesized by a conventional method. Methods: All the newly synthesized derivatives were characterized by determining their melting point, retention factor from thin-layer chromatography, and spectral methods (Infrared, 1H NMR spectroscopy, 13C NMR spectroscopy, Mass spectroscopy) and evaluated for their anti-diabetic activity. Results: [{5-[(1, 3-benzothiazol-2-ylsulfanyl) methyl]-1, 3, 4-oxadiazol-2-yl} sulfanyl) methyl] derivatives have been made and characterized using physical and spectral methods. The in-vitro anti-diabetic screening study revealed that BZT1 and BZT4 exhibited high inhibition against glucose uptake assay and alpha-amylase enzyme. But only the derivative BZT4 showed inhibition against alpha-glucosidase enzyme. Conclusion: Various benzothiazole substituted oxadiazole derivatives were synthesized, characterized by spectral studies. The anti-diabetic studies revealed that the synthesized derivatives have significant anti-diabetic properties and further structure-activity relationship studies may develop more potent and less toxic molecules.

Migration behavior of benzobicyclon hydrolysate and associated influencing factors in different agricultural soils

Benzobicyclon is a triketone pro-herbicide that needs to be hydrolyzed to form an active compound benzobicyclon hydrolysate (BH). This study aimed to investigate the migration behavior of BH in different types of agricultural soil and the associated influencing factors. Soil thin-layer chromatography and column leaching tests were used to study the migration behavior of BH in these soils. Based on the mobility retention factor (Rf = 0.34–0.90), the mobility of BH in thin soil layers was ranked in the order Lixisols > Anthrosols > Ferralsols > Phaeozems. The Rf value of BH was linearly positively correlated with soil sand content and pH, and negatively correlated with other physical and chemical properties of soil. BH was difficult to leach in Phaeozems, less difficult to leach in Ferralsols, and easy to leach in Anthrosols and Lixisols. Increasing the BH dosage and rainfall amount or adding humic acid and anionic (dodecyl benzene sulfonic acid) or nonionic (Tween-80) surfactant blocked BH migration in soil columns. In contrast, increasing the leaching solution pH and adding cationic surfactant (cetyl trimethyl ammonium bromide) promoted BH migration in soil columns.BH application has a low risk of groundwater pollution in Phaeozems and Ferralsols, but poses a potential threat to groundwater in Anthrosols and Lixisols.

Preliminary pharmaceutico-analytical study of Mukhadooshikaharalepa Churna

Introduction: Lepa is a bahirparimarjana chikitsa that helps in bringing samyata in sthanika dosha and dhatu. Many lepa are mentioned in Ayurveda pharmaceutics for the treatment of mukhadooshika. Among it, one is a combination of Lodhra, Kustumburu, Vacha, Vatapallava, and Narikelashuktya. Mukhadooshika is a type of kshudraroga, featuring the formation of pidaka on face. The symptoms of mukhadooshika resembles with acne vulgaris. Aim: An attempt is made to analyze the physico-chemical parameters of the mukhadooshikahara lepa churna. Materials and methods: The pharmaceutical preparation is easy and simple with easily available ingredients. The organoleptic characters like appearance, odour, taste and physico-chemical parameters like pH, total ash. Water Soluble ash, Alcohol soluble extractives, Water soluble extractives, loss on drying and HPTLC were carried out. Observations and results: The obtained results were discussed in the present paper. Discussion and conclusion: Mukhadooshikahara lepa churna is a simple preparation and can be prepared by easily available drugs. HPTLC fingerprinting at different wavelengths was carried out. At 254 nm, 366nm and 620nm 11, 8 and 10 peaks were found with different retention factor starting from 0.02 to 0.80, 0.03 to 0.096 and 0.07 to 0.80respectively. The analytical study findings can be taken as a preliminary standard for mukhadooshikahara lepa churna.

Optimization, purification and characterization of α-glucosidase inhibitors from Streptomyces costaricanus EBL.HB6 isolated in Vietnam

BackgroundDiabetes, a disease that has been a great burden of the treatment cost for patients and society. There are many drugs have been used to cure this disease available on the pharmaceutical market. One of the most prevalent source to produce these compounds are microorganism. Among them, Streptomyces sp. are popular microorganisms used for the production of α-glucosidase inhibitors (AGIs). Methods and ResultsIn this study, different cultivation conditions were optimized to enhance the production of AGIs. Purification and evaluation of AGIs from S. costaricanus EBL.HB6 were also performed. Our results demonstrated that Streptomyces costaricanus EBL.HB6 had the highest α-glucosidase inhibitory activity among 6 Streptomyces sp. strains were isolated in Vietnam. The 16S rRNA sequencing of isolating HBC6-2 indicated 99% identity to the corresponding sequence of Streptomyces costaricanus, and was registered on GenBank with the code MT 453944.1. Streptomyces costaricanus EBL.HB6 was able to produce melanin yellow pigment, and its aerial and substrate mycelia have brown and yellow-grey pigment on ISP2 cultivating medium, respectively. The α-glucosidase inhibitory activity of the supernatant was increased by a factor of 1.2 under optimal conditions (media containing 1.5% glucose, 1.2% yeast extract at 28°C, initial pH of 6.5, and culture time for 120 h) in comparison with the initial media and condition. The purified efficacy of a-glucosidase inhibitors was 5% with a retention factor of 0.71 on thin-layer chromatography and IC50 value of 9.59 mg/mL.ConclusionsStreptomyces costaricanus EBL.HB6 strain was selected, purified and evaluated for its highly producible of α-glucosidase inhibitors.

How to keep employees in your organization

The article is devoted to the relevance of using corporate culture in an organization and its role as a retention factor for employees. Particular attention is paid to corporate culture as a motivating factor for work. The authors conclude that the interest of employees in furtherwork, and therefore their retention in the company, is directly related to the activities within the framework of corporate culture.

EVALUATION OF THE QUALITY OF DIFFERENT BRANDS OF ASCORBIC ACID IN FREETOWN, SIERRA LEONE

Objective: This study evaluates the registration status and the quality of nine brands of Vitamin C sold in Freetown, Sierra Leone, using official and non-official methods of analysis. Methods: The parameters taken into consideration during the study include non-official methods (friability and disintegration) and the official methods (identification test, uniformity of dosage unit, and assay by titrimetric and colorimetric tests). The different brands of vitamin C were selected and classified as registered and unregistered based on the data derived from the National Medicines Regulatory Authority. Results: One vitamin C product collected was unregistered at the National medicines regulatory authority (Pharmacy Board of Sierra Leone). All nine vitamin C products met the requirements for uniformity of dosage unit. The vitamin C products also conformed to the BP specification for friability and identification test (retention factor). The identification test showed that each brand contained vitamin C (ascorbic acid). The disintegration test was not applicable for chewable tablets. Three of the four non-chewable vitamin C products complied with the BP specification for disintegration, while one failed and did not meet the requirement. The assay results for ascorbic acid using titration and colourimetric method were comparable and appropriate for determining vitamin C. Out of a total of nine samples; seven met the requirement for BP specification (Passed) for assay. In contrast, one product did not meet the BP requirement (failed), and one sample had more vitamin C than the Pharmacopoeia limit. Conclusion: Periodic quality evaluation and routine checks for pharmaceutical products can ascertain the quality of products, their storage conditions and identify potential counterfeit medications.

Development and Validation of Retention Models in Supercritical Fluid Chromatography for Impregnation Process Design

The retention factor is the key quantity for the thermodynamic analysis of the retention mechanism in chromatographic experiments. In this work, we measure retention factors for moderately polar solutes on four silica-based porous matrices as stationary phases by supercritical fluid chromatography. Elution of the solutes is only possible with binary mixtures of supercritical carbon dioxide (sc-CO2) and modifier (methanol) due to the low polarity of pure sc-CO2. The addition of modifiers makes the retention mechanism more complex and masks interactions between solute and stationary phase. In this work, we develop and validate several retention models that allow the obtaining of retention factors in modifier-free sc-CO2. Such models pave the way for quantifying adsorption interactions between polar solutes and non-swellable porous matrices in pure sc-CO2 based on retention data obtained in sc-CO2/modifier mixtures. The obtained information will thereby facilitate the understanding and design of impregnation processes, which are often performed in modifier-free conditions.

Experiments and Simulation on Integrated Approach of CO2 EOR and Storage in Mature Reservoirs

CO2 storage mechanisms in an EOR process in mature reservoirs are measured to determine three types of storage factors, which are introduced into compositional numerical simulation. The hybrid objective function coupli ng the oil recovery factor and the CO2 storage ratio is proposed to optimize the injection and production parameters in CO2 flooding. Three storage factors of the oil and water partition coefficient, the permeability change coefficient and the CO2 retention factor are measured in a laboratory, which is utilized to modify the grid properties of oil, brine, rock in compositional numerical simulation. The restart procedure is automatically adopted to consider these storage mechanisms in CO2 EOR. The bi-objective function of the oil recovery factor and the CO2 storage ratio is used to optimize the injection and production parameters for CO2 EOR, which concludes the design principles on CO2 EOR and storage. The oil and water partition coefficient defined as the ratio of the CO2 solubility in the oil phase and the brine phase is a constant for a specific reservoir condition. The permeability change coefficient caused by the mineral dissolution effect of carbonate water decreases slightly in the early stage and increases gradually with the long term injection. The CO2 retention factor that is induced by the relative permeability hysteresis decreases with the pressure and the permeability. These equivalent treated methods that modify fluids and rock in the real-time are inserted into the procedure of compositional numerical simulation to take into account the storage mechanisms in CO2 EOR. The results show that the effect of the storage mechanisms on EOR is evident. Furthermore, the bi - objective optimization indicates that the injection rate should be reduced largely in the medium and the later stages to control gas channeling as the EOR scenario is focused. And the bottom wellhole pressure of producers should be decreased to the lower level to maximize oil recovery. As the storage scenario is concentrated, the injection rate is required to be slightly controlled. As the producers are shut off, the injection rate must be increased significantly to maximize CO2 storage. The storage mechanisms in the CO2 EOR process have not been understood thoroughly. The methodology of numerical simulation coupling CO2 EOR and storage is not mature, which is still not taken into account in commercial software. The results above provide a way to optimize CO2 EOR and storage simultaneously, which is significant for the large scale storage after CO2 EOR in mature oilfield.