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Green and Sustainable Chemistry 2015年第3期5卷 128-135页

作者： pranab jyoti das Jesmin Begum Department of Chemistry Gauhati University Guwahati India

A microwave mediated solvent free one pot synthesis of formazans is developed using the solid acid, KHSO4. The products were obtained in a short reaction time in high yield. This study was undertaken to find an alternative and green method for the synthesis of formazans in the absence of corrosive mineral acids, buffered solutions and volatile organic compounds (VOCs).

关键词： Formazan One Pot Synthesis Solvent Free Four Component Reaction Microwave KHSO4

Solvent Free One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles Catalyzed by Secondary Amine Based Ionic Liquid and Defective Keggin Heteropoly Acid

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Green and Sustainable Chemistry 2013年第4期3卷 6-13页

作者： pranab jyoti das Jupitara das Munni Ghosh Sabera Sultana Department of Chemistry Gauhati University Guwahati India Indian Institute of Technology Guwahati India

Secondary amine based ionic liquid and defective Keggin type heteropoly acid (HPA) are separately used for efficient one-pot four-component synthesis of 1,2,4,5-tetrasubstituted imidazoles assisted by microwave (MW). Eco-friendly solvent free procedure, short reaction time, high yield of products and reusability of catalysts are important features of the synthesis. A comparative study on the efficiency of the two catalysts is reported. This work further demonstrates the alternate use of urea, instead of often used ammonium acetate, as source of nitrogen.

关键词： Ionic Liquids Keggin Heteropolyacid Microwave Tetrasubstituted Imidazole Solvent Free Synthesis Multicomponent Reaction

Gas Chromatographic Method for Identification and Quantification of Commonly Used Residual Solvents in Pharmaceuticals Products

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American Journal of Analytical Chemistry 2024年第8期15卷 241-252页

作者： Sreekanta Nath Dalal pranab Kumar das Department of Applied Chemistry & Chemical Engineering Faculty of Engineering & Technology University of Dhaka Dhaka Bangladesh Department of Applied Chemistry & Chemical Engineering Faculty of Engineering University of Rajshahi Rajshahi Bangladesh

Background: Impurities are not expected in the final pharmaceutical products. All impurities should be regulated in both drug substances and drug products in accordance with pharmacopeias and ICH guidelines. Three different types of impurities are generally available in the pharmaceutical’s product specification: organic impurities, inorganic impurities, and residual solvents. Residual solvents are organic volatile chemicals used or generated during the manufacturing of drug substances or drug products. Purpose: The aim of this study is to develop a cost-effective gas chromatographic method for the identification and quantification of some commonly used solvents—methanol, acetone, isopropyl alcohol (IPA), methylene chloride, ethyl acetate, tetrahydrofuran (THF), benzene, toluene, and pyridine—in pharmaceutical product manufacturing. This method will be able to identify and quantify the multiple solvents within a single gas chromatographic procedure. Method: A gas chromatography (GC) equipped with a headspace sampler and a flame ionization detector, and a column DB 624, 30-meter-long × 0.32-millimeter internal diameter, 1,8 μm-thick, Brand-Agilent was used to develop this method. The initial GC oven temperature was 40°C and held for 5 minutes. It was then increase to 80˚C at a rate of 2˚C per minute, followed by a further increase to 225˚C at a rate of 30˚C per minute, with a final hold at 225˚C for 10 minutes. Nitrogen was used as a carrier gas at a flow rate of 1.20 mL per minute. Dimethyl sulfoxide (DMSO) was selected as sample solvent. Results: The developed method is precise and specific. The percent RSD for the areas of six replicate injections of this gas chromatographic method was within 10.0 and the recovery result found within 80.0% to 120.0%.

关键词： Method Development Gas Chromatography Compendial Method GDP Specificity Recovery

Robustness Study and Superior Method Development and Validation for Analytical Assay Method of Atropine Sulfate in Pharmaceutical Ophthalmic Solution

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American Journal of Analytical Chemistry 2024年第5期15卷 151-164页

作者： Md. Nazmus Sakib Chowdhury Sreekanta Nath Dalal Md. Ariful Islam Md. Anwar Hossain pranab Kumar das Shakawat Hossain Parajit das Department of Pharmacy Bangabandhu Sheikh Mujibur Rahman Science and Technology University Gopalganj Bangladesh Department of Applied Chemistry and Chemical Engineering University of Dhaka Dhaka Bangladesh Department of Applied Chemistry and Chemical Engineering University of Chittagong Chattogram Bangladesh Department of Applied Chemistry and Chemical Engineering Islamic University Kushtia Bangladesh Department of Applied Chemistry and Chemical Engineering University of Rajshahi Rajshahi Bangladesh Department of Pharmacy International Islamic University Chittagong Chittagong Bangladesh Department of Applied Chemistry and Chemical Engineering Bangabandhu Sheikh Mujibur Rahman Science and Technology University Gopalganj Bangladesh

Background: The robustness is a measurement of an analytical chemical method and its ability to contain unaffected by little with deliberate variation of analytical chemical method parameters. The analytical chemical method variation parameters are based on pH variability of buffer solution of mobile phase, organic ratio composition changes, stationary phase (column) manufacture, brand name and lot number variation;flow rate variation and temperature variation of chromatographic system. The analytical chemical method for assay of Atropine Sulfate conducted for robustness evaluation. The typical variation considered for mobile phase organic ratio change, change of pH, change of temperature, change of flow rate, change of column etc. Purpose: The aim of this study is to develop a cost effective, short run time and robust analytical chemical method for the assay quantification of Atropine in Pharmaceutical Ophthalmic Solution. This will help to make analytical decisions quickly for research and development scientists as well as will help with quality control product release for patient consumption. This analytical method will help to meet the market demand through quick quality control test of Atropine Ophthalmic Solution and it is very easy for maintaining (GDP) good documentation practices within the shortest period of time. Method: HPLC method has been selected for developing superior method to Compendial method. Both the compendial HPLC method and developed HPLC method was run into the same HPLC system to prove the superiority of developed method. Sensitivity, precision, reproducibility, accuracy parameters were considered for superiority of method. Mobile phase ratio change, pH of buffer solution, change of stationary phase temperature, change of flow rate and change of column were taken into consideration for robustness study of the developed method. Results: The limit of quantitation (LOQ) of developed method was much low than the compendial method. The % RSD fo

关键词： Robustness Method Validation HPLC Compendial Method Method Development GDP LOQ

Higher Grain-Filling Rate in Inferior Spikelets of Tolerant Rice Genotype Offset Grain Yield Loss under Post-Anthesis High Night Temperatures

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Rice science 2024年第5期31卷 572-586,I0059-I0061页

作者： Nitin SHARMA Bhupinder SINGH Subbaiyan Gopala KRISHNAN Haritha BOLLINEDI pranab Kumar MANDAL Milan Kumar LAL Prakash Kumar JHA P.V.Vara PRASAD Anjali ANAND Division of Plant Physiology Indian Council of Agricultural Research(ICAR)-Indian Agricultural Research Institute(IARI)New Delhi 110012India Division of Environment Science ICAR-IARINew Delhi 110012India Division of Genetics ICAR-IARINew Delhi 110012India ICAR-National Institute for Plant Biotechnology New Delhi 110012India Division of Crop Physiology and Biochemistry ICAR-National Rice Research InstituteCuttack 753006India Department of Plant and Soil Sciences Mississippi State UniversityStarkvilleMS 39762USA Feed the Future Innovation Lab for Collaborative Research on Sustainable Intensification Kansas State UniversityManhattanKS 66506USA Department of Agronomy Kansas State UniversityManhattanKS 66506USA

Increased nighttime respiratory losses decrease the amount of photoassimilates available for plant growth and yield. We hypothesized that the increased respiratory carbon loss under high night temperatures(HNT) could be compensated for by increased photosynthesis during the day following HNT exposure. Two rice genotypes, Vandana(HNT-sensitive) and Nagina 22(HNT-tolerant), were exposed to HNT(4 ℃ above the control) from flowering to physiological maturity. They were assessed for alterations in the carbon balance of the source(flag leaf) and its subsequent impact on grain filling dynamics and the quality of spatially differentiated sinks(superior and inferior spikelets). Both genotypes exhibited significantly higher night respiration rates. However, only Nagina 22 compensated for the high respiration rates with an increased photosynthetic rate, resulting in a steady production of total dry matter under HNT. Nagina 22 also recorded a higher grain-filling rate, particularly at 5 and 10 d after flowering, with 1.5- and 4.0-fold increases in the translocation of ^(14)C sugars to the superior and inferior spikelets, respectively. The ratio of photosynthetic rate to respiratory rate on a leaf area basis was negatively correlated with spikelet sterility, resulting in a higher filled spikelet number and grain weight per plant, particularly for inferior grains in Nagina 22. Grain quality parameters such as head rice recovery, high-density grains, and gelatinization temperature were maintained in Nagina 22. An increase in the rheological properties of rice flour starch in Nagina 22 under HNT indicated the stability of starch and its ability to reorganize during the cooling process of product formation. Thus, our study showed that sink adjustments between superior and inferior spikelets favored the growth of inferior spikelets, which helped to offset the reduction in grain weight under HNT in the tolerant genotype Nagina 22.

关键词： high night temperature inferior grain pasting property radiolabeled sugar superior grain

Environmental impact of aquaculture-sedimentation and nutrient loadings from shrimp culture of the southeast coastal region of the Bay of Bengal

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Journal of Environmental Sciences 2004年第3期16卷 466-470页

作者： Biplob das Yusuf Sharif Ahmed Khan pranab das Department of Earth and Atmospheric Sciences Institute of Marine SciencesInstitute of Marine Sciences 1-26 Earth Sciences Building University of Alberta Edmonton Alberta T6G 2E3CanadaUniversity of ChittagongChittagong 4331BangladeshUniversity of ChittagongChittagong 4331Bangladesh

Nutrient loadings were measured for surface seawater and bottom sediments of semi intensive and improved extensive shrimp culture pond, adjacent estuary, and fallow land in the south east coastal region of Bangladesh during August, 2000—January, 2001 to evaluate the impact of shrimp culture. The mean levels of nutrients found in the pond surface water were 108 780 mg/L for CaCO 3, 0 526 mg/L for NH + 4 N, 3 075 wt% for organic carbon, 7 00 mg/L for PO 4 P, 5 57 mg/L for NO 3 N, and 7 33 mg/L for chlorophyll a. The maximum mean value of H 2S(0 232 mg/L) was found in estuarine water. Nutrients loading were found to be decreased with distance from the shrimp farm discharge unit in estuarine water. The mean level of organic matter, total nitrogen, and organic carbon were found in higher concentrations in sediments of cultured pond compared to bottom soil of adjacent fallow land at the same elevation. Extractable Ca values were found in higher concentration(550 33 ppt) in adjacent fallow land, as the shrimps for molting in shrimp ponds use extractable Ca. The relation between seawater H 2S value and sediment pH ( r= -0 94); sediment organic carbon and sediment pH values ( r= -0 76), sediment total nitrogen and sediment pH ( r= - 0 74) were found to be highly negatively correlated. Whereas the relation between seawater H 2S value and sediment total nitrogen ( r= 0 92), water NH + 4 N and sediment pH ( r= 0 66) were found to be positively correlated. The results revealed that load of nutrients at eutrophic level in estuarine water, and decrease of soil pH; leading to acid sulphate soil formation indicates a negative impact of shrimp culture.

关键词： environment eutrophication impact nutrients shrimp culture

Petrological Characteristics and Genesis of the Central Indian Ocean Basin Basalts

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Acta Geologica Sinica(English Edition) 2012年第5期86卷 1154-1170页

作者： pranab das Sridhar D.IYER Sugata HAZRA National Institute of Oceanography(Council of Scientific and Industrial Research)Dona Paula Goa 403004India Department of Applied Geology Indian School of MinesDhanbad 826004India School of Oceanographic Studies Jadavpur UniversityKolkata 700032India

The Central Indian Ocean Basin （CIOB） basalts are plagioclase-rich, while olivine and pyroxene are very few. The analyses of 41 samples reveal high FeOT （～10-18 wt%） and TiO 2 （～1.4-2.7 wt%） indicating a ferrobasaltic composition. The basalts have high incompatible elements （Zr 63-228 ppm; Nb ～1-5 ppm; Ba ～15-78 ppm; La ～3-16 ppm）, a similar U/Pb （0.02-0.4） ratio as the normal midoceanic basalt （0.16±0.07） but the Ba/Nb （12.5-53） ratio is much larger than that of the normal midoceanic ridge basalt （～5.7） and Primitive Mantle （9.56）. Interestingly almost all of the basalts have a significant negative Eu anomaly （Eu/Eu＊=0.78-1.00） that may have been a result of the removal of feldspar and pyroxene during crystal fractionation. These compositional variations suggest that the basalts were derived through fractional crystallization together with low partial melting of a shallow seated magma.

关键词： basalts Genesis Central Indian Ocean Basin

Structure-based discovery of *** phytochemicals as potential inhibitors against Monkeypox(mpox)viral protein

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Journal of Biosafety and Biosecurity 2024年第3期6卷 157-169页

作者： Ranjan K.Mohapatra Ahmed Mahal pranab K.Mohapatra Ashish K.Sarangi Snehasish Mishra Meshari A.Alsuwat Nada N.Alshehri Sozan M.Abdelkhalig Mohammed Garout Mohammed Aljeldah Ahmad A.Alshehri Ahmed Saif Mohammed Abdulrahman Alshahrani Ali S.Alqahtani Yahya A.Almutawif Hamza M.A.Eid Faisal M Albaqami Mohnad Abdalla Ali A.Rabaan Department of Chemistry Government College of EngineeringKeonjhar 758002OdishaIndia Department of Medical Biochemical Analysis College of Health TechnologyCihan University–ErbilErbilKurdistan RegionIraq Department of Chemistry CV Raman Global UniversityBhubaneswarOdishaIndia Department of Chemistry School of Applied SciencesCenturion University of Technology and ManagementBalangirOdishaIndia School of Biotechnology Campus-11KIIT Deemed-to-be-UniversityBhubaneswar 751024OdishaIndia Clinical Laboratory Sciences Department College of Applied Medical SciencesTaif UniversityAl-Taif 21974Saudi Arabia Internal Medicine Department King Khalid University Medical CityCollege of MedicineAbha 61481Saudi Arabia Department of Basic Medical Sciences College of MedicineAlMaarefa UniversityRiyadhSaudi Arabia Department of Community Medicine and Health Care for Pilgrims Faculty of MedicineUmm Al-Qura UniversityMakkah 21955Saudi Arabia Department of Clinical Laboratory Sciences College of Applied Medical SciencesUniversity of Hafr Al BatinHafr Al Batin 39831Saudi Arabia Department of Clinical Laboratory Sciences Faculty of Applied Medical SciencesNajran UniversityNajran 61441Saudi Arabia Department of Medical Laboratory Sciences Faculty of Applied Medical SciencesKing Khalid UniversityAbha 61481Saudi Arabia mDepartment of Medical Laboratories Technology College of Applied Medical SciencesTaibah UniversityMadinah 41411Saudi Arabia Biology Department College of ScienceIslamic University of MadinahMadinah 42351Saudi Arabia Pediatric Research Institute Children’s Hospital Affiliated to Shandong UniversityJinanShandong 250022China Molecular Diagnostic Laboratory Johns Hopkins Aramco HealthcareDhahran 31311Saudi Arabia College of Medicine Alfaisal UniversityRiyadh 11533Saudi Arabia Department of Public Health and Nutrition The University of HaripurHaripur 22610Pakistan

Outbreaks of Monkeypox(mpox)in over 100 non-endemic countries in 2022 represented a serious global health *** a neglected disease,mpox has become a global public health issue.A42R profilinlike protein from mpox(PDB ID:4QWO)represents a potential new lead for drug development and may interact with various synthetic and natural *** this report,the interaction of A42R profilinlike protein with six phytochemicals found in the medicinal plant Ficus religiosa(abundant in India)was *** on the predicted and compared protein–ligand binding energies,biological properties,IC_(50) values and toxicity,two compounds,kaempferol(C-1)and piperine(C-4),were *** characteristics and quantitative structure–activity relationship(QSAR)of these two compounds were determined,and molecular dynamics(MD)simulations were *** silico examination of the kaempferol(C-1)and piperine(C-4)interactions with A42R profilin-like protein gave best-pose ligandbinding energies of–6.98 and–5.57 kcal/mol,*** predicted IC_(50) of C-1 was 7.63 lM and 82 lM for *** data indicated that kaempferol and piperine are non-mutagenic,and the QSAR data revealed that piperlongumine(5.92)and piperine(5.25)had higher log P values than the other compounds *** simulations of A42R profilin-like protein in complex with C-1 and C-4 were performed to examine the stability of the ligand–protein ***/C and C-4 showed the highest affinity and activities,they may be suitable lead candidates for developing mpox therapeutic *** study should facilitate discovering and synthesizing innovative therapeutics to address other infectious diseases.

关键词： Monkeypox Mpox Phytochemical Molecular docking MD simulation ADMET QSAR

Microtexture and Distribution of Minerals in Hydrothermal Barite-Silica Chimney from the Franklin Seamount, SW Pacific: Constraints on Mode of Formation

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Acta Geologica Sinica(English Edition) 2014年第1期88卷 213-225页

作者： Durbar RAY Dalayya KOTA pranab das L.Surya Prakash V.D.KHEDEKAR Anil L.PAROPKARI Abhay V.MUDHOLKAR CSIR-National Institute of Oceanography Indian School of Mines

An extinct hydrothermal barite-silica chimney from the Franklin Seamount of the Woodlark Basin, in the southwestern Pacific Ocean, was investigated for mineral distribution and geochemical composition. Six layers on either side of the orifice of a chimney show significant disparity in color, mineral assemblage and major element composition. Electron microscope（SEM） images reveal that the peripheral wall of the chimney is composed of colloform silica, suggesting that incipient precipitation of silica-saturated hydrothermal fluid initiated the development of the chimney wall. Intermediate layers, between the exterior wall and the inner fluid-orifice, dominate with barite and sulfides. Low Sr-to-Ba ratios（SrO/BaO = 0.015–0.017） indicate restricted fluid-seawater mixing, which causes relatively high-temperature formation of the intermediate layers. Whereas the innermost layer bordering the chimney orifice is characterized by more silica and a higher Sr-to-Ba ratio（SrO/BaO = 0.023）, could have formed due to a paragenetic shift from a high-temperature active phase to a cooler waning stage of formation. A paragenetic shift is also probably responsible for the change in mineral formation mechanism that resulted in the textural variation of barite and colloform silica developed during different growth phases of this barite-silica chimney.

关键词： mineralogy oceanography geochemistry Franklin seamount barite-silica chimney

Improved photocatalytic degradation of organic dye using Ag3PO4/MoS2 nanocomposite

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Frontiers of Materials Science 2017年第4期11卷 366-374页

作者： Madhulika SHARMA pranab Kishore MOHAPATRA Dhirendra BAHADUR Department of Metallurgical Engineering and Materials Science Indian Institute of Technology Bombay Powai Mumbai 400076 India Department of Physics Indian Institute of Technology Bombay Powai Mumbai 400076 India

Highly efficient Ag3PO4/MoS2 nanocomposite photocatalyst was synthe- sized using a wet chemical route with a low weight percentage of highly exfoliated MoS2 （0.1 wt.%） and monodispersed Ag3PO4 nanoparticles （-5.4 nm）. The structural and optical properties of the nanocomposite were studied using various characterization techniques, such as XRD, TEM, Raman and absorption spectroscopy. The composite exhibits markedly enhanced photocatalytic activity with a low lamp power （60 W）. Using this composite, a high kinetic rate constant （k） value of 0.244 min^-1 was found. It was observed that -97.6% of dye degrade over the surface of nanocomposite catalyst within 15 min of illumination. The improved photocatalytic activity of Ag3PO4/MoS2 nanocomposite is attributed to the efficient interfacial charge separation, which was supported by the PL results. Large surface area of MoS2 nanosheets incorporated with well dispersed Ag3PO4 nanoparticles further increases charge separation, contributing to enhanced degradation efficiency. A possible mechanism for charge separation is also discussed.

关键词： Ag2PO4/MoS2 nanocomposite methylene blue degradation efficiency photocatalysis