Phytochemical Screening and In Vitro Antioxidant and Anti-inflammatory Activities of Aerial Parts of Euphorbia hirta L.

Euphorbia hirta L (Euphorbiaceae) also called asthma herb has long been prescribed in traditional medicine because it exhibits diverse pharmacological actions due to the presence of alkaloids, flavonoids, polyphenols, triterpenoids, and saponins. The present study is aimed at the study of phytochemical and antioxidant activity and anti-inflammatory screening of E. hirta. Extraction of dried powder was performed followed by phytochemical screening using color reactions. Total phenolic content (TPC) and total flavonoid content (TFC) of the extracts were estimated by Folin-Ciocalteu and Aluminum chloride method respectively. The antioxidant activity was studied by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. Anti-inflammatory activity was studied by using protein denaturation in vitro bioassay. Phytochemical screening showed the presence of flavonoids, alkaloids, and phenolic compounds. TPC, TFC and antioxidant activity (IC50) of the extract were found as 288.10 mg gallic acid equivalent per gram (GAE/g), 29.36 mg quercetin equivalent per gram (QE/g) and 32.23 µg/mL (p<0.05) respectively. Diclofenac sodium and E. hirta extract showed the maximum inhibition of 91.28% and 68.20% respectively at the concentration of 1000 µg/mL compared with control (p>0.05). The phenolic compounds and flavonoids exert antioxidant and anti-inflammatory activities because of their scavenging ability. The demonstrated antioxidant and anti-inflammatory activities may be the rationale behind some of its folkloric uses and also may be responsible for some of its pharmacological effects. Thus, E. hirta can be considered a good source of antioxidants and anti-inflammatory actions, which might be beneficial for combating oxidative stress.

Chemical Constituents of the Essential Oil of Invasive Chromolaena odorata leaves in Central Nepal

Chromolaena odorata is one of the widely distributed invasive alien plants in the tropical to subtropical regions of Nepal. It has the ability to impact native species in its invaded range by multiple modes such as allelopathy including volatilization. This study aims to identify volatile chemical components in the essential oil of C. odorata. The leaf samples of C. odorata were collected from the Radha Krishna Community Forest, Chitwan district of Nepal. The essential oil from the leaves of C. odorata was extracted and the chemical composition of the oil was analyzed by gas chromatography (GC) and GC–mass spectrometry (GC–MS). A total of 19 chemical components from the oil were identified. The major components identified were linalool (21.64%); β-pinene (9.43%); 1,3-cycloheptadiene (8.92%); β-cubebene (7%); cinnamaldehyde (5.30%) and caryophyllene oxide (4.94%). O-methoxy cinnamaldehyde and isoeugenyl acetate were not listed by previous studies as the components in the essential oils of C. odorata. The components identified by this study have allelopathic effects on native plant species, anti-herbivory properties, and medicinal values. Therefore, this study could be important to understand plant invasiveness and utilization of the plant for the extraction of bioactive compounds may contribute to control and manage the plants in the invaded areas.

Utilization of Charred Water Hyacinth (Jalkumvi) as Biosorbent for Removal of Ca(II) Ion from Aqueous Solution

A promising adsorbent, charred water hyacinth (CWH) for the removal of Ca(II) from the aqueous solution was explored by heat treatment of water hyacinth followed by chemical activation with acidified zinc chloride (ZnCl2). The adsorbent was characterized using scanning electron microscopy (SEM) and electron dispersive X-ray (EDX) spectroscopy. Batch adsorption techniques were conducted for Ca(II) adsorption to assess the adsorption isotherm, effect of pH, contact time, initial Ca(II) concentration, adsorbent doses, and adsorption kinetics. The SEM micrograph illustrates the rough and irregular surface morphology and EDX spectra confirm the successful adsorption of Ca(II) on the adsorbent surface. The equilibrium adsorption data better fitted to the Freundlich isotherm model having a maximum adsorption capacity (qmax) of 319.75 mg/g. The highest percentage of adsorption was found at pH 1.5. The adsorption of Ca(II) by CWH decreased at the higher metal concentration and lower adsorbent doses. The adsorption of Ca(II) ions onto CWH followed the pseudo-second-order kinetics model. . Overall, these results suggested that the as-prepared CWH can be used as an eco-friendly, economical and efficient alternative for the removal of Ca(II) from the aqueous solution.

Phytoconstituents and Biological Activities of Zanthoxylum armatum Fruit Extract

The essential oil and methanol extract of the fruit of Zanthoxylum armatum DC were extracted by hydro-distillation in the Clevenger apparatus and cold percolation technique respectively and their chemical and biological studies were performed. The chemical compositions of essential oil were analyzed by GC-MS analysis. The most abundant ingredient was Linalool (75.31%) followed by E-methyl cinnamate (11.73%) and limonene (9.45%). The nature of the functional groups present in the extract was analyzed by performing FTIR analysis. The methanol extract showed the presence of alkaloids, flavonoids, glycosides, polyphenols, terpenoids, volatile oils, tannins, and saponins. Biological activities of the oil and extract were evaluated by performing brine shrimp bioassay, antibacterial activity test, and antifungal activity test. Essential oil (LC50 = 76.70 µg/mL) and methanol extract (LC50 = 62.25 µg/mL) were found highly cytotoxic against brine-shrimp nauplii. The essential oil showed potent antibacterial activity against gram-positive bacteria Bacillus subtilis, Micrococcus leutus, and Staphylococcus aureus with the zone of inhibitions 11 mm, 16 mm, and 17 mm respectively and moderate antibacterial activity against the gram-negative bacteria Klebsiella pneumonia, Enterobacter cloacae, and Pseudomonas aeruginosa with the zone of inhibitions 9 mm, 5 mm and 6 mm respectively. The methanol extract was found to be effective against gram-positive bacteria only. Both oil and extract showed moderate antifungal activity against bacterial strains.

Non-carcinogenic and Carcinogenic Risk Assessment of Heavy Metals Exposure to Indoor Dust in Kathmandu, Nepal

The present study was carried out to assess the contamination of heavy metals in indoor household dust of Kathmandu, Nepal, and its adverse effect on the indoor environment and human health. The concentrations of four heavy metals (Cd, Cr, Ni, and Pb) in a total of ninety-three (N = 93) indoor dust samples collected from four different types of land use zones viz., commercial, heavy traffic, residential, and control (undisturbed) of Kathmandu were determined by the flame atomic absorption spectrophotometer (FAAS). The mean concentrations of Cd, Cr, Ni, and Pb in indoor dust samples over the study zones were 0.89, 158.1, 113.3, and 65.3 mg kg−1, respectively. The land use zones showed the various degree of metal contamination in indoor dust ranging from moderate to considerable level. PLI showed a high pollution load in the monitored locations, indicating an alarming condition and the urgent need for immediate remedial actions. Hazard quotient (HQ) values indicated ingestion as the major pathway of indoor dust heavy metal exposure to children while the inhalation pathway remained dominant in adults. Hazard index (HI) values showed no probable non-carcinogenic risk of the heavy metals present in the indoor dust of Kathmandu. For carcinogenic health risk, TLCR values were found within the acceptable safe limit indicating no cancer risk for both the receptor groups.

Synthesis, Characterization and Biological Screening of Azepine Derivative: 2-hydroxy-1,3-di(naphthalene-2-yl)-1H-benzo[b]azepine-5(4H)one

The synthesis of unsaturated heterocyclic compounds containing nitrogen atoms in the ring is very important due to its various biological application in the pharmaceutical industry. Azepine derivatives find numerous application almost every field in medicinal chemistry and some of its are commercially available as drugs. The two-component of azepine derivatives were synthesized by using the aniline and maleic anhydride as a starting material followed by condensation with sodium borohydride in presence of dry benzene, subsequently cyclization by polyphosphoric acid then, finally by an addition reaction with naphthalene-2-ol to form the desired derivative. The formation of the synthesized azepine derivative was confirmed by spectral techniques such as IR, 1H-NMR, and 13C-NMR. The antibacterial assay shows that the synthesized compound (2A) possesses the most highly potent activity in the Bacillus subtilis and moderate activity against other different strains of bacteria and fungi.

Facile Synthesis of Nanosized Magnesium-Aluminium Layered Double Hydroxides

We report facile methods of preparing nanosized hydrotalcite-like compounds, the layered double hydroxides (LDH), with ordinary chemistry laboratory settings to educate the young scientists from high schools to undergraduate university level fostering their research interest in preparing these nanomaterials of practical importance. Coprecipitation and urea hydrolysis methods have been recommended as facile routes of preparing the magnesium-aluminum layered double hydroxides (Mg-Al LDHs). The LDH thus prepared were characterized by Fourier transform infrared (FTIR) spectroscopic and powder X-ray diffraction (XRD) techniques. The observed weakening of some FTIR peaks and XRD planes shifting concerning standard JCPDS 89-5434 data implied the slight structural variation of the compounds and the presence of impurities. The average grain diameter of LDH particles was found in the range of 20 to 60 nm.

Green Synthesis of Zirconia (ZrO2) Nanoparticles using Curcuma Longa Extract and Investigation of Compressive Strength of Epoxy resin (EP)/ZrO2 Nanocomposites

Zirconia (ZrO2) nanoparticles are polymorphic materials having a wide range of applications. It can be synthesized via green as well as chemical synthesis methods. In this work, ZrO2 nanoparticles were synthesized by the green method using Curcuma longa extract. Curcuma longa extract was prepared using the standard method. The synthesized ZrO2 was characterized by the X-ray diffraction (XRD) analysis and Fourier transform infra-red (FTIR) spectroscopy for their structural and size analysis. The analysis of the XRD pattern of ZrO2 showed the tetragonal phase structure and the size was calculated using the Debye Scherrer equation which was about 34.55 nm. The FTIR spectra analysis showed a broad absorption peak particularly at about 774 cm-1 and about 499 cm-1 correspondings to Zr-O2-Zr asymmetric and Zr-O stretching modes, respectively. The characterized ZrO2 nanoparticles were used for the preparation of epoxy resin/ZrO2 nanocomposites. The compressive strength of pure epoxy resin and epoxy resin/ZrO2 nanocomposites were measured by a compressive strength tester and the result indicates the high amount of zirconia was not suitable for the nanocomposites.

Synthesis and Characterization of High Molecular Weight Chitosan, and Antioxidant Activity of Its Chitosan Oligosaccharide Encapsulation

High molecular weight nanocrystalline chitosan (HMWNC)with Mw of 350 kDa and 66.92% DDA was prepared by alkaline N-deacetylation of chitin that was abundantly obtained after demineralization and deproteinization of pulverized crab shells, and commercially available chitosan oligosaccharide (COS) with average Mw< 3000 Da and 87% DDA was encapsulated with HMWNC. The encapsulation of COS as a pharmaceutical ingredient into HMWC was hypothesized to enhance the bioavailability of COS in target cells. The HMWNC encapsulated chitosan oligosaccharide (COS-HMWNC) showed in vitro antioxidant activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals (IC50 = 512.6±14.4 μg/mL) while others showed less than 50% inhibition at 1000 μg/mL. The lower the molecular weight of chitosan, the higher was the antioxidant activity. The study showed that the encapsulation of COS molecules in HMWNCcould be used as a simple and effective way of enhancing the antioxidant activity of COS.

Effect of pH on Homogeneous Photodegradation of Eosin Y Dye

Eosin Y (EY), an anionic dye, also known as Eosin Yellow or Bromoeosin, or Acid red 27 is an industrial dye. The residual dye, discharged as one of the components of the untreated effluent, into the adjacent surface and causes water pollution. Photodegradation of EY was investigated at 29 oC in homogeneous aqueous media using UVA light (≈400 – 320 nm) in acetate buffer solution as a function of pH (3.08-7.08). At higher pH, there was no effect of this light on the dye in the solution. Results show that the initial rate of photocolorization increased with decreasing the pH of the dye solution.