Journal of Nepal Chemical Society

Structural, Optical and Antimicrobial Properties of Carbohydrate-Capped Cadmium Sulfide Nanoparticles

Subhav Adhikari — 2023-04-25

Cadmium sulfidenanoparticles (CdSNPs) were prepared through the chemical precipitation process where sweet potato starch and glucose-functioned as capping agents. Ultraviolet-Visible (UV-Vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques were applied for the analysis of prepared CdSNPs. The absorption peaks in the UV-Vis spectroscopy towards the lower wavelength region compared to the bulk CdS (512 nm) indicated the formation of CdS particles in the nanometer scale range. FTIR spectroscopy showed the characteristic absorption peaks of the CdSNPs along with the functional groups present in starch and glucose, suggesting the possible interaction between CdSNPs and capping agents. The XRD revealed crystallographic information such as the average crystallite size and shape of CdSNPs. Using the Scherrer equation, the average crystallite size of CdSNPs was determined to be 11.48 nm and 16.03 nm for starch-capped and glucose-capped CdSNPs (CdS-St andCdS-Gl)respectively. Antibacterial and antifungal activities of the prepared CdSNPs were found to be highly efficient for various pathogenic bacteria and fungi. Hence in the present study, the new synthetic route of CdSNPs was applied, and antimicrobial activities were performed

Free and Open Source Codes for Computational Chemistry Research Initiation: A Conspectus

Jhashanath Adhikari — 2023-04-25

Computational chemistry is a field of current active research in science that can supplement and complement the regular experimental methods and validate or propose new theoretical formulations. It has contributed from basic to advanced levels of investigation in a synergistic manner. The mathematical experiments can be pursued with minimal resources and are sustainable making it a good approach for institutions with limited resources. The freely available computer programs that are suitable for solving various types of problems in chemistry and interdisciplinary areas are briefly mentioned. The general features and specificity of some selected codes that are adaptable for undergraduate and graduate-level courses and research in Nepal are highlighted. A recommendation is made for the incorporation of adequate theoretical courses and parallel laboratory sessions in the existing syllabus for obtaining a trained and skilled workforce qualified for national and global careers in computational chemistry and also for research and development in Nepal.

Chemical Modification of Banana Peels and Banana Pseudostem for the Adsorptive Removal of Chromium (VI) from Aqueous Solution

Sujata Adhikari — 2023-04-25

The removal of Cr(VI) from the water was studied using raw and modified banana peels and pseudostem wastes as bio-adsorbent under the batch adsorption technique at room temperature. The chemical modification of raw adsorbents was performed by treating them with concentrated sulphuric acid. Characterizations were performed by FTIR, XRD, and SEM analyses. The raw form of adsorbents showed insignificant adsorption compared to the charred form. Therefore, the further process was carried out using modified adsorbents only. The maximum adsorption capacity for charred banana peel (CBP) and charred banana pseudostem (CBS)was found to be maximum at optimum equilibrium pH 2. The adsorption data fitted well with the Langmuir adsorption model and followed pseudo-second-order kinetics. Therefore, owing to high efficiency and low cost with maximum removal percentage, thus prepared adsorbents are expected to be used satisfactorily in the adsorption of Cr(VI) from aqueous solutions.

Synthesis, Cytotoxicity, Antibacterial and Antioxidant Activity of New 2-Substituted Benzimidazole Containing 1,2,4-Triazoles

Prateek Aryal — 2023-04-25

The development of a potent new drug with high biological activity is a challenge in drug design and is of strategic importance. Due to the increasing resistance of pathogens on the available drugs, there is always a demand for designing a potent drug with high biological activity. The pharmacological effects have been observed in compounds containing different moieties of pharmaceutical importance such as triazole, Schiff’s base, benzimidazole.Triazole thione, Schiff’s bases, and two new compounds containing three pharmacophores viz. triazole, benzimidazole, and Schiff base incorporated in a single compound were prepared by applying different synthetic reactions. Different spectroscopic methods, including FT-IR, UV-vis, ¹H-NMR, and ¹³C-NMR, were used to confirm the structure of the prepared compounds. All compounds exhibited moderate antibacterial activity against Staphylococcus aureus (ATCC 6538P) and Staphylococcus epidermidis (ATCC 1228). Antioxidant activity was carried out by DPPH radical scavenging test and among the tested five compounds, the IC₅₀ value of 4-amino-3-(2-hydroxyphenyl)-1H-1,2,4-triazole-5(4H)-thione was found to be 32.364 μg.mL^-1 which is closer to the ascorbic acid that was found to be 28.546 μgmL^-1. All tested compounds were toxic against brine shrimp where 2-(5-((1H-benzo[d]imidazol-2-yl)thio)-4-((4-chlorobenzylidene) amino)-4H-1,2,4-triazol-3-yl) was comparatively more toxic (LC₅₀= 26.827 μgmL^-1).

Chemical and Instrumental Analysis of Limestone and Red Clay from Makwanpur District for Cement Production

Rupesh Kumar Dubey — 2023-04-25

Limestone and red clay are widely used in construction as primary raw materials since they are readily available and economically viable. The present work has been carried out primarily to explore the fresh reserves of acceptable raw materials in the Makawanpur district for producing cement. Four limestone and four red clay samples were collected from different locations in the Makwanpur district. The samples were analyzed using chemical (titrimetric and gravimetric) and instrumental (wave dispersive X-ray fluoroscopy, WDXRF) methods. Chemical, as well as instrumental methods, were utilized not only to authenticate the results but also to evaluate the merits of these methods. Loss on ignition (LOI), determined gravimetrically, ranged from 41.98 to 39.03% for limestone samples and from 9.24 to 7.82% for red clay samples.Chemical analysis of limestone samples revealed the presence of 40.72 to 48.53% CaO, 0.97 to 1.96% Fe₂O₃, 1.83 to 3.64% Al₂O₃ and 5.69 to 12.84% SiO₂. Chemical analysis of red clay revealed the presence of 2.26 to 3.27% CaO, 9.54 to 14.20% Fe₂O₃, 12.90 to 19.68% Al₂O₃ and 46.70 to 61.50% SiO₂. The WDXRF analysis of limestone revealed the presence of 39.37 to 50.46% CaO, 0.8 to 2.29% Fe₂O₃, 1.34 to 3.01% Al₂O₃ and 4.75 to 17.03% SiO₂. The WDXRF analysis of red clay revealed the presence of 1.98 to 3.59% CaO, 9.89 to 13.96% Fe₂O₃, 12.45 to 19.82% Al₂O₃ and 47.62 to 60.94% SiO₂.

The analyzed compositions were found to lie within the range allowed by the Nepal Bureau of Standards and Metrology (NBSM) for the manufacture of high-quality cement. The results from the chemical methods were found to be in good agreement with the results from the instrumental method. This research is expected to contribute to the cement industry not only by providing insight into raw material compatibility but also by evaluating the merits of these methods.

Hydrochemical characterization of the Ramsar-listed Koshi Tappu Wetland, Nepal

Shristi Neupane — 2023-04-25

Nepal abounds a vast array of freshwater bodies, from sub-tropical lowlands to glacier-fed highlands with varying water quality. This study evaluated the spatial variations in water quality at the Koshi Tappu Wetland, the first Ramsar site of Nepal, located in the eastern Tarai region within the Koshi Tappu Wildlife Reserve. Nineteen water quality parameters were chosen and analyzed from twenty-one different sampling points within the wetland. Parameters including pH, EC, TDS, turbidity, and DO were analyzed on-site, whereas HCO₃^-, Cl^-, NH₄⁺, NO₃^-, SO₄^2- PO₄^3-, K⁺, TH, Ca²⁺, Mg²⁺, CaH, MgH, Na⁺, and Fe³⁺ were analyzed in the laboratory. Multivariate methods such as hierarchical agglomerative cluster analysis (CA) and principal component analysis (PCA), and geochemical indices such as piper and mixing diagrams were applied to assess the spatial variation in water quality. Findings indicated Ca²⁺ as the principal cation and HCO₃^- as the principal anion regulating the hydrochemistry of the wetland. Based on CA, three spatial clusters were observed, which depicted variations in chemical composition with the PCA results highlighting the primary contamination sources and controlling factors of the sampling locations with 84.13% of the total variance. Findings from the PCA and ionic relationship analyses elucidated that the hydrochemistry of the Koshi Tappu wetland is mainly controlled by carbonate weathering processes with a minor contribution of silicate weathering and anthropogenic activities.

Chemical Hydrological Features and Water Quality Evaluation of Phewa Lake of Pokhara Valley Gandaki Province of Nepal

Sangita Poudel — 2023-04-25

This study was conducted to investigate the hydrochemical characteristics and water quality of Phewa lake Pokhara. Water samples were collected and major hydrochemical features were analyzed viz., Transparency, pH, electrical conductivity (EC), total dissolved solids (TDS), total alkalinity (TA), total hardness(TH), dissolved oxygen (DO), microbial analysis (MA), nitrate (NO₃^¯), phosphate (PO₄^3¯), ammonia(NH₃), sulfate (SO₄^2¯), chloride(Cl^¯), iron(Fe²⁺/Fe³⁺), phosphorus (P) and dissolved solids (DS). The obtained values of the hydrochemical characteristic of lake water have been compared with the world health organization (WHO). The presence of phosphate concentration and the hardness in Phewa lake is higher than the WHO value indicating the problem of rapid eutrophication. This indicates that Phewa lake water has more magnesium and calcium soluble salt. Thus, the rapid eutrophication and higher concentration of organic matter could be a serious problem for lake sustainability. Various types of natural and anthropogenic activities like agricultural runoff, urbanization, discharge of domestic sewage, solid waste dump, and industrial effluent are the major problem for lake sustainability.

Chemical Synthesis, Characterization, and Computational Investigation of Two Schiff Bases Derived From 3-(2-Hydroxyphenyl)-4-amino-4H-1,2,4-triazole-5- thiol and Their Corresponding Oxovanadium(IV) Complexes

Bharat Prasad Sharma — 2023-04-25

A triazole, 2-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)phenol, has been prepared from 2-hydroxybenzoic acid by routine multi-step chemical synthesis. It was then used in synthesizing two different Schiff base ligands (L₁ and L₂). Their respective oxovanadium (IV) complexes (ML₁ and ML₂) were consequently synthesized and characterized by different experimental techniques like elemental analysis, FTIR spectroscopy, UV-Visible spectroscopy, and EPR spectrometry. The cyclic voltammetry measurements showed the electrochemically stable nature of the complexes. The powder X-ray diffraction patterns revealed the presence of monoclinic crystals with particle sizes of ca. 15-17 nm for both complexes. DFT calculations were performed for the determination of geometrical models, energetic stability, electronic properties, spectral features, and reactivity of the synthesized ligands and complexes. The spectral characterization of the complexes suggests a square-pyramidal geometry around VO (IV)group and was supported by computational results derived from the proposed models. This work shows that computational calculation along with experimental characterization provides better insights into new chemical compounds and their properties that could be performed in parallel as a regular tool.

Comparative Phytochemical and Biological Study of Tinospora cordifolia (Thunb.) Miers and Justicia adhatoda L. Plants Collected from West Rukum of Nepal

Biraj Oli — 2023-04-25

Medicinal plants contained an impressive number of modern drugs and are believed to be a precious natural reservoir that has been continuously studied for its pharmacological activities against various ailments. Tinospora cordifolia and Justicia adhatoda are widely used shrubs in folk and ayurvedic systems of medicine. Phytochemical screening of different fractions of the extract of the bark of T. cordifolia and leaf, stem, and flowers of J. adhatoda was done and results show the presence of alkaloids, flavonoids, phenolics, glycosides, terpenoids in both plants. The antibacterial potency of medicinal plant extracts has been tested against Bacillus subtilis ATC6051 and Enterococcus faecalis ATCC29212 by disc diffusion assay. The leaves extract of J. adhatoda showed good antibacterial activities towards both the Enterococcus faecalis and Bacillus subtilis bacteria, however, the extract of T. cordifolia was found not soo effective with those bacteria. The methanol extract of T. cordifolia stem showed the strongest 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging activity with IC₅₀ values 8.213μg/mL very close to standard ascorbic acid (22.451 μg/mL). Furthermore, results showed that T. cordifolia is a good source of antioxidants as compared to the J. adhatoda. The total phenolic content (TPC) was highest in methanolic extract of T. cordifolia (46.463 mg GAE/g extract) while the J. adhatoda had lower values (31.167 mg GAE/g extract) by taking gallic acid as a standard. The total flavonoid content (TFC) was highest in methanol extract of J. adhatoda leaves (13.030 mg QE/g extract) while T. cardifolia had lower values (2.112 mg QE/g extract) which were determined by taking quercetin as a standard. The result revealed that the TPC is higher in T. cordifolia and TFC value higher in J. adhatoda and that can be correlated with the antimicrobial and antioxidant properties of phytoconstituents although the plants have been used for the similar ethnomedical purpose in society.

Starch/ Polyvinyl Alcohol (PVA) Blend Bioplastics: Synthesis and Physicochemical Properties

Binod Shrestha — 2023-04-25

Starch-based bioplastics are prepared from the waste of food materials and are widely used as the short-lived biodegradable plastic for household and food packaging applications. In this work, glycerol plasticized starch (extracted from potato peels)bioplastics blended with Polyvinyl Alcohol (PVA) in various compositions (wt.-%) were prepared, and characterized using Fourier Transform Infrared (FTIR) spectroscopy and their physicochemical properties such as water absorption, biodegradable properties, and acid-base resistance were investigated. The FTIR spectra of starch-based bioplastics blended with PVA of the peak at 2924 cm^-1 portrayed good compatibility between starch bioplastics and PVA. The water absorption test showed that the increase in starch proportion in starch/PVA blend increases water absorption capacity. The higher weight ratio of starch in starch/ PVA blend bioplastics degraded more rapidly than other bioplastics. Furthermore, the bioplastics of higher starch content resist acid and base for 45 and 42 hours respectively without being dissolved.

Preparation, spectroscopic analysis, and biological assessment of heteroleptic Zr(II) and Pd(II) complexes from Otc/Sal mixed ligands

Rohit Kumar Dev — 2023-04-25

The two new novel heteroleptic complexes of the type [M(II)L₁.L₂] (M= Zr(II) & Pd(II), L₁= oxytetracycline (Otc), and L₂=salicylaldehyde (Sal)) have been synthesized and analyzed by physical measurements such as CHN, pH, and conductivity. The conductivity data revealed the electrolytic nature of Pd(II)Otc/Sal and the non-electrolytic nature of the Zr(II)Otc/Sal metal complex of mixed ligand. The structural characterizations of the metal complex were approved by spectroscopic analysis methods, such as IR, ¹H & ¹³C-NMR, UV/ Visible, and ESI-MS studies. Thermal analysis (TGA/DTA) determines the thermal and kinetic stabilities of the metal complexes using a popular Coats-Redfern equation through which the activation parameters can be calculated easily. SEM can determine the surface morphology of metal complexes. The selected bond lengths, bond angles, final optimized energy, and geometry of complexes were obtained by running an optimization task in the 3D molecular modeling software program via Chem 3D Pro. 12.0.2. The final geometrical energy was found to be 921.7712 for Zr(II)Otc/Sal and 914.6006 Kcal/mol for Pd(II)Otc/Sal complexes. Based on the above study, Zr(II)Otc/Sal complex has tetrahedral geometry and the Pd(II)Otc/Sal complex has square planar geometry. The complexes were tested in vitro for antibacterial susceptibility study against various strains of clinical pathogenic bacteria such as Staphylococcus aureus (Gram-positive), Proteus mirabilis, and Escherichia coli (Gram-negative). For the antibacterial study, the Kirby-Bauer paper disc diffusion technique is applied by using 50, 25, and 12.5 μg/μL concentrations of the metal complex. Good antibacterial sensitivity was found against all tested pathogens in all synthesized complexes.

Cytotoxicity of Compounds Isolated from Usnea aciculifera

Sajan L Shyaula — 2023-04-25

Atranorin 1, Usnic acid 2, and D-Arabinitol 3 were isolated from Usnea aciculifera by extensive column chromatography. The structures were elucidated based on the comprehensive spectral analysis including FT IR, GC MS, ESI MS, ¹³C NMR, and ¹H NMR. The compounds were evaluated for their cytotoxic activity against LN-229 glioblastoma cancer cell line by performing Sulforhodamine B assay (SRB). Usnic acid 2 showed strong cytotoxic activity against LN-229 glioblastoma cancer cell with an IC₅₀ value of 3.09 μg/mL.

Study of Phytochemical Constituent and Biological Activities of Methanolic Extract of Rhizomes of Neopicrorhiza scrophulariiflora and Roots of Rheum australe collected from the Alpine Region of Nepal

Ganesh Prasad Kumai — 2023-04-25

Rhizomes of Neopicrorhiza scrophularii flora and roots of Rheum australe were collected from the alpine regions of the Jumla district of Nepal. The phytochemical analysis of the methanolic extract of these plants revealed the presence of polyphenols, flavonoids, quinones, saponins, and tannins. The total phenolic and flavonoid content in the extracts of N. scrophulariiflora were estimated to be 141.27±1.414 mg GAE/gm and 43.48±5.476 QE/gm respectively and that in the extracts of R. austral were estimated to be 101.54±4.061 mg GAE/gm and 24.97±2.857 mg QE/gm respectively. A brine shrimp lethality test was performed with the extracts of N. scrophulariiflora and R. austral against brine shrimp nauplii and results revealed high toxicity of the extracts towards nauplii with LC₅₀ values 173.78μg/mL and 257.03μg/mL respectively. N. scrophulariiflora showed the strongest DPPH radical scavenging activity with IC₅₀ value of 57.49 μg/mL in comparison to R. austral whose IC₅₀ was determined to be 68.91μg/mL, ascorbic acid taken as standard with IC₅₀ value 49.05μg/ml. In α-amylase inhibition assay, N. scrophulariiflora extract exhibited strong activity with IC₅₀ value 140.67μg/mL while that of R. austral extract showed mild activity with IC₅₀ value 192.88μg/mL. All the biological studies revealed that N. scrophulariiflora extract is more active than that R. austral extract. Column chromatography of the extract of N. scrophulariiflora was performed and 50 % methanolic fraction was further subjected to FTIR and GC-MS analysis. The GC-MS analysis showed various compounds and among them, 13 major compounds were identified.

Phytochemical Screening, Antioxidant, Antibacterial, and α-Amylase Inhibitory Activity of Moringa oleifera Lam. Leaves

Surya Kant Kalauni — 2023-04-25

Moringa oleifera is a perennial deciduous plant abundant in tropical countries that contains many important bioactive compounds. This study aimed to evaluate phytochemical analysis, antioxidant, antibacterial, and α-amylase inhibitory activities of the methanol and hexane leaf extracts of the plant collected from Nepal. Phytochemical screening of the extracts revealed the presence of a wide spectrum of secondary metabolites such as alkaloids, flavonoids, phenolics, saponins, tannins, terpenoids, etc. Methanol and hexane extracts showed the presence of significant quantities of total phenolics (207.75± 2.75 mg GAE/g, and 137.09 ± 1.1 mg GAE/g) and total flavonoids (94.56 ± 1.88 mg QE/g, and 82.71 ± 1.47 mg QE/g) respectively. The methanol extract exhibited higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The half-maximal concentration causing 50% inhibition of the radical (IC₅₀) of methanol and hexane extracts was 39.19 ± 0.33 and 61.07 ± 1.46 μg/mL respectively which are comparable to that of standard ascorbic acid (28.90 ± 0.24 μg/mL. Methanol extract of M. oleifera leaves showed moderate antibacterial activity against Staphylococcus aureus (ATCC25923), Bacillus cereus, and Klebsiella pneumonia (ATCC700603). In-vitro antidiabetic activity was performed by a starch-iodine method using α-amylase enzyme and methanol extract showed significant antidiabetic activity (IC₅₀ value 31.78 ± 0.52 μg/mL). The results of this study corroborate the potential application of the plant in traditional medicine and the drug discovery process.

Chemical and biological analysis of extracts of Acorus calamus L.

Aaradhana Pokharel — 2023-04-25

The powdered plant materials of Acorus calamus were subjected to successive extraction using the cold percolation method with methanol, hexane, and chloroform solvent. Qualitative phytochemical analysis of methanol, hexane, and chloroform extracts showed the presence of alkaloids, saponins, glycosides, sterols, triterpenoids, and carbohydrates. Five different major compounds were identified by GC-MS analysis of the chloroform extract, with isoprothiolane (83.11%) being the most prevalent. The total phenolic content in the chloroform extract was calculated at 17.39 mg Gallic acid equivalent /g and the total flavonoid content was 3.37 mg quercetin equivalent/g of dry extract. The IC₅₀ value of chloroform extract was found to be 576.19 μg/mL, and the LC₅₀ value was found to be 66.21 μg/mL. Antibacterial activity was shown in Staphylococcus aureus in chloroform extract with a ZOI of 7 mm.

Kinetics of Catalytic Oxidation of Carbenicillin: A Degradation Approach for Penicillanic Acid Derivatives (PADs)

Yuv Raj Sahu — 2023-04-25

Diperiodatocuprate [DPC (III)] was selected to predict the kinetic studies for carbenicillin (CRBC) oxidation in the basic media. The investigation was completed in the presence of CoCl₃ as a catalyst by using a UV/Visible spectrophotometer at 298K temperature and 0.01 mol-dm^-3 ionic strength confirming a 1:4 stoichiometry between CRBC and DPC (III). Both spectral and elemental analysis was used to identify the final products. Monoperiodatocuperate [MPC (III)] was found to be the primary active species of DPC (III). Pseudo-first order reaction was declared for DPC (III), while fractional order reactions were noticed in the case of CRBC (substrate), Co (III) catalyst as well as KOH (alkali). However, the reaction was determined to be in negative fractional order for periodate. Spectral evidence, determination of various rate constants, and both activation, as well as thermodynamic parameters, were used to predict plausible mechanisms.

Determination of Total Phenolic and Flavonoid Content, Antidiabetic, and Antioxidant Activities of Leaves and Seeds Extracts of Eucalyptus robusta Sm. and Ageratina adenophora Spreng

Sarala Regmi — 2023-04-25

The present study aimed at the determination of total phenolic and flavonoid content and biological activities of Eucalyptus robusta (Sm.) and Ageratina adenophora (Spreng.) growing in Kathmandu Nepal. People have been using these medicinal plants for many years against infectious diseases and to control diabetes. The extraction of plant secondary metabolites was done by the cold percolation method. The total phenolic (TPC) and flavonoid content (TFC) were quantified by the Folin-Ciocalteu phenol reagent and aluminium chloride colorimetric method. The α-amylase enzyme inhibition activity was performed to evaluate the antidiabetic property of plant extracts. The antioxidant potential of plant extracts was evaluated by DPPH (2,2-diphenyl- 1-picrylhydrazyl) radical scavenging assay. The methanol extract of Ageratina adenophora Spreng leaves is found rich in plant secondary metabolites of a yield percentage 36.83% whereas Eucalyptus robusta Sm. leaves and seeds have a yield percentage of 30.75% and 27.12% respectively. The extract of E. robusta leaves showed the highest phenolic content (200.89±6.67 mg gallic acid equivalent/g of dry extract) and A. adenophora Spreng. leaves extract showed the flavonoid content (0.49±0.02 mg quercetin equivalent/g of dry extract) among the three samples studied, respectively. The extract of E. robusta Sm. seeds showed the strongest DPPH radical scavenging activity with a half-maximal inhibitory concentration IC₅₀ of 110.8±1.73 μg/mL. The extract of A. adenophora Spreng. was found potent towards α-amylase enzyme inhibition activity of IC₅₀ 16.05±0.24 μg/mL whereas E. robusta Sm. leaves and seeds extracts showed IC₅₀ 21.93±1.24 mg/mL and 21.82±0.09 mg/mL respectively. This study showed the leaves and seeds extracts of these two medicinal plants are found rich in phenolic and flavonoid compounds. These medicinal plants could be used to isolate the natural antioxidant and antidiabetic compounds that may be potential drug candidates in the future drug discovery process. This study supports providing scientific validation for using these medicinal plants against diabetes.