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Fulltext The In Vitro α-Glucosidase Inhibition Activity of Various Solvent Fractions of Tamarix dioica and 1H-NMR Based Metabolite Identification and Molecular Docking Analysis

Niaz A, Adnan A, Bashir R, Mumtaz MW, Raza SA, Rashid U, et al.

Plants (Basel), 2021 Jun 02;10(6).
PMID: 34199333 DOI: 10.3390/plants10061128

The Tamarix dioica (T. dioica) is widely used medicinal plant to cure many chronic ailments. T. dioica is being used to manage diabetes mellitus in traditional medicinal system; however, very little scientific evidence is available on this plant in this context. The current study involves the fractionation of crude methanolic extract of T. dioica using n-hexane, ethyl acetate, chloroform, and n-butanol. The screening for antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was carried out. The in vitro antidiabetic potential was assessed by measuring α-glucosidase inhibition. Total phenolic and flavonoid contents were also determined for each fraction. The metabolites were identified using highly sensitive and emerging 1H-NMR technique. The results revealed the ethyl acetate fraction as the most potent with DPPH scavenging activity of 84.44 ± 0.21% and α-glucosidase inhibition with IC50 value of 122.81 ± 2.05 µg/mL. The total phenolic and flavonoid content values of 205.45 ± 1.36 mg gallic acid equivalent per gram dried extract and 156.85 ± 1.33 mg quercetin equivalent per gram dried extract were obtained for ethyl acetate fraction. The bucketing of 1H-NMR spectra identified 22 metabolites including some pharmacologically important like tamarixetin, tamaridone, quercetin, rutin, apigenin, catechin, kaempferol, myricetin and isorhamnetin. Leucine, lysine, glutamic acid, aspartic acid, serine, and tyrosine were the major amino acids identified in ethyl acetate fraction. The molecular docking analysis provided significant information on the binding affinity among secondary metabolites and α-glucosidase. These metabolites were most probably responsible for the antioxidant activity and α-glucosidase inhibitory potential of ethyl acetate fraction. The study ascertained the ethnomedicinal use of T. dioica to manage diabetes mellitus and may be a helpful lead towards naturopathic mode for anti-hyperglycemia.
Fulltext Goat milk enhances memory of d-galactose-induced aging rats

Safdar A, Azman KF, Zakaria R, Ab Aziz CB, Rashid U

J Tradit Complement Med, 2021 Mar;11(2):117-122.
PMID: 33728271 DOI: 10.1016/j.jtcme.2020.02.005

Background and aim: Goat milk is a food of high nutritional value and has been proved to possess strong antioxidant and anti-inflammatory properties. However, thus far, little is known of its possible effects on brain especially on memory during aging. The aim of this study was to assess the effect of goat milk supplementation on memory in d-galactose-induced aging rat model.
Experimental procedure: Fifty-two male Sprague Dawley rats were randomly divided into four groups: 1) control group, 2) goat milk treated group, 3) d-galactose treated group, and 4) goat milk plus d-galactose treated group. Goat milk (1 g/kg orally) and/or d-galactose (120 mg/kg subcutaneously) were administered continuously for six weeks preceded and followed by novel object recognition and T-maze test.
Results and conclusion: Prior to goat milk and d-galactose administration, there was no significant difference (p > 0.05) in memory between all groups. Goat milk administration alone significantly increased short- and long-term memory (p
Molecular hybridization conceded exceptionally potent quinolinyl-oxadiazole hybrids through phenyl linked thiosemicarbazide antileishmanial scaffolds: In silico validation and SAR studies

Taha M, Ismail NH, Ali M, Rashid U, Imran S, Uddin N, et al.

Bioorg Chem, 2017 04;71:192-200.
PMID: 28228228 DOI: 10.1016/j.bioorg.2017.02.005

The high potential of quinoline containing natural products and their derivatives in medicinal chemistry led us to discover a novel series of compounds 6-23 based on the concept of molecular hybridization. Most of the synthesized analogues exhibited potent leishmanicidal potential. The most potent compound (23, IC50=0.10±0.001μM) among the series was found ∼70 times more lethal than the standard drug. The current series 6-23 conceded in the development of fourteen (14) extraordinarily active compounds against leishmaniasis. In silico analysis were also performed to probe the mode of action while all the compounds structure were established by NMR and Mass spectral analysis.
Biodiesel Production from Citrillus colocynthis Oil Using Enzymatic Based Catalytic Reaction and Characterization Studies

Nehdi IA, Sbihi HM, Blidi LE, Rashid U, Tan CP, Al-Resayes SI

Protein Pept Lett, 2018;25(2):164-170.
PMID: 28240158 DOI: 10.2174/0929866524666170223150839

BACKGROUND: Biodiesel is a green fuel consisting of long chain fatty acid monoalkyl esters, which can be blended with diesel or used alone which is usually produced from vegetable oils/fats by either lipasecatalyzed transesterification. In this investigation, an enzyme (Novozym 435) catalyzed process was optimized to prepare methyl esters from crude Citrullus colocynthis oil (CCO) by transesterification of CCO with methanol. However, as per our knowledge, lipase-catalyzed transesterification have not been used for biodiesel production from Citrullus colocynthis.
OBJECTIVE: The purpose of this work was to transesterify the CCO in the presence of Candida antarctica lipase as catalyst and methanol. Additionally, the physicochemical parameters/fuel properties of the Citrullus colocynthis methyl ester (CCME) were assessed and compared.
METHODS: Lipase-catalyzed reactions were carried out in three necked flask (50 mL) attached with reflux condenser and thermometer, immersed in oil bath at constant stirring speed (400 rpm). The reaction mixture was consisted of CCO and varying the calculated amount of methanol, tert-butyl alcohol, and Novozym 435. The experimental parameters reaction time, methanol/oil molar ratio, reaction temperature, tert-butanol content, Novozym 435 content and water content were optimized for the transesterification reaction. The CCME yield was measured using gas chromatograph. The fuel properties of the produced CCME were determined as per American Society for Testing and Materials (ASTM) and European (EN) biodiesel standard methods.
RESULTS: In this study, an enzymatic catalyst was employed to synthesize the CCME from CCO via transesterification. Several variables affecting the CCME yield were optimized as lipase quantity (4%), water content (0.5%), methanol/oil molar ratio (5:1), reaction temperature (43 °C), reaction medium composition (80% tertbutanol/ oil), and reaction time (3.7 h). A CCME yield of 97.8% was achieved using enzyme catalyzed transesterification of CCO under optimal conditions. The significant biodiesel fuel properties of CCME, i.e. cloud point (0.70 °C); cetane number (49.07); kinematic viscosity (2.27 mm2/s); flash point (143 °C); sulfur content (2 ppm) density (880 kg/m3) and acid value (0.076 mg KOH/g) were appraised. CCME also exhibited long-term storage stability (4.80 h) and all the biodiesel fuel properties were within the range of standards (ASTM D6751 and EN 14214).
CONCLUSION: The lipase-catalyzed transesterification produced better conversion than the base-catalyzed reaction. The fuel properties of CCME were within the limits of the ASTM D6751 and EN14214 standards. Furthermore, CCME showed good oxidative stability and a long shelf life due its high natural antioxidant content. CCME showed better fuel properties and long-term storage stability due to which it can be used as a potential alternative fuel.
Fulltext Optimization and blends study of heterogeneous acid catalyst-assisted esterification of palm oil industry by-product for biodiesel production

Akinfalabi SI, Rashid U, Arbi Nehdi I, Yaw Choong TS, Sbihi HM, Gewik MM

R Soc Open Sci, 2020 Jan;7(1):191592.
PMID: 32218977 DOI: 10.1098/rsos.191592

The optimum conditions to produce palm fatty acid distillate (PFAD)-derived-methyl esters via esterification have been demonstrated with the aid of the response surface methodology (RSM) with central composite rotatable design in the presence of heterogeneous acid catalyst. The effect of four reaction variables, reaction time (30-110 min), reaction temperature (30-70°C), catalyst concentration (1-3 wt.%) and methanol : PFAD molar ratio (3 : 1-11 : 1), were investigated. The reaction time had the most influence on the yield response, while the interaction between the reaction time and the catalyst concentration, with an F-value of 95.61, contributed the most to the esterification reaction. The model had an R2-value of 0.9855, suggesting a fit model, which gave a maximum yield of 95%. The fuel properties of produced PFAD methyl ester were appraised based on the acid value, iodine value, cloud and pour points, flash point, kinematic viscosity, density, ash and water contents and were compared with biodiesel EN 14214 and ASTM D-6751 standard limits. The PFAD methyl ester was further blended with petro-diesel from B0, B3, B5, B10, B20 and B100, on a volumetric basis. The blends were characterized by TGA, DTG and FTIR. With an acid value of 0.42 (mg KOH g-1), iodine value of 63 (g.I2/100 g), kinematic viscosity of 4.31 (mm2 s-1), the PFAD methyl ester has shown good fuel potential, as all of its fuel properties were within the permissible international standards for biodiesel.
Potential heterogeneous nano-catalyst via integrating hydrothermal carbonization for biodiesel production using waste cooking oil

Abdullah RF, Rashid U, Hazmi B, Ibrahim ML, Tsubota T, Alharthi FA

Chemosphere, 2022 Jan;286(Pt 3):131913.
PMID: 34418662 DOI: 10.1016/j.chemosphere.2021.131913

Hydrothermal carbonization (HTC) provides alternatives technique to produce a nanosize activated carbon from biomass with a high surface area. Herein, this study we prepared empty fruit bunch-based activated carbon (EFBHAC) using HTC technique. The activated carbon was then functionalized with K2CO3 and Cu(NO3)2 to produce bifunctional nano-catalyst for simultaneous esterification-transesterification of waste cooking oil (WCO). The physicochemical properties were performed i.e. N2 sorptions analysis, TPD-CO2/NH3, FESEM, EDX, FTIR and XRD analysis. The results revealed that produced EFBHAC possessed a BET surface area of 4056.17 m2 g-1, with pore volume of 0.827 cm3 g-1 and 5.42 nm of pore diameter resulting from hydrolysis, dehydration decarboxylation, aromatization and re-condensation during HTC process. Impregnation of EFBHAC with K2CO3 and Cu(NO3)2 granted a high amount of basicity and acidity of 9.21 mmol g-1 and 31.41 mmol g-1, respectively, accountable to high biodiesel yield of 97.1%, produced at the optimum condition of 5 wt% of catalyst loading, 12:1 of methanol to oil molar ratio at 70 °C for 2 h. More than 80% of biodiesel was produced after the 5th cycle depicted the good reusability. The transformations from WCO to biodiesel was confirmed via 1H NMR, FTIR and TGA analysis. Fuel properties revealed kinematic viscosity of 3.3 mm2 s-1, cetane number of 51, flash point of 160.5 °C, cloud and pour point of 11 °C and -3 °C, respectively. These results show the excellent potential of waste materials to prepare bifunctional nano-catalysts to produce higher biodiesel yield which has potential to be commercialized.
Fulltext Heating effect on quality characteristics of mixed canola cooking oils

Baig A, Zubair M, Sumrra SH, Nazar MF, Zafar MN, Jabeen K, et al.

BMC Chem, 2022 Jan 17;16(1):3.
PMID: 35039092 DOI: 10.1186/s13065-022-00796-z

BACKGROUND: The subcontinent is famous for its variety of seasonal foods cooked in vegetable seed cooking oils at elevated heating. Oils are often of poor quality that effect to consumer health. The work, therefore, planned to examine the effects of heat on the quality of mixed canola cooking oils (MCCOs). MCCOs were analyzed by preparing volatile fatty acid methyl esters (FAMEs) and for physiochemical properties.
RESULTS: A major change was observed in the FAs composition of various MCCOs as coded K-1 to K-5. MCCOs were found rich in unsaturated 9-octadecanoic acid (oleic acid C18:1) and 9, 12-octadecadienoic acid (linoleic acid C18:2) along saturated octadecanoic acid (stearic acid C18:0). Results reveals that canola oil samples are mixed in the range of 4-30% with other vegetable oils and animal fats. The quality of canola cooking oils further reduced after heating to 100 °C, 200 °C and 350 °C, respectively. Quality parameters of MCCOs were significantly altered after heating and found as color (510-520 nm to 570-600 nm), mass 220-237 g to 210-225 g, volume 250 mL to 239 mL, pH (6.76-6.89), specific gravity (0.87-0.92), refractive index (1.471-1.475), saponification value (SV) (0.7-2.5), un-saponifiable matter (2.4-9.8%) and acid value (AV) (1.20-5.0 mg KOH).
CONCLUSION: Heating of oils at elevated temperature have shown a significant effect on pH, specific gravity and un-saponifiable matter (p-value
Fulltext Fabrication of Highly Microporous Structure Activated Carbon via Surface Modification with Sodium Hydroxide

Hafizuddin MS, Lee CL, Chin KL, H'ng PS, Khoo PS, Rashid U

Polymers (Basel), 2021 Nov 16;13(22).
PMID: 34833252 DOI: 10.3390/polym13223954

The aim of this study was to select the optimal conditions for the carbonization process followed by surface modification treatment with sodium hydroxide (NaOH) to obtain a highly microporous activated carbon structure derived from palm kernel shells (PKS) and coconut shells (CS). The effects of the carbonization temperature and NaOH concentration on the physiochemical properties, adsorption capability, specific surface area, surface morphology, and surface chemistry of PKS and CS were evaluated in this study. The results show that surface-modified activated carbons presented higher surface area values (CS: 356.87 m2 g-1, PKS: 427.64 m2 g-1), smaller pore size (CS: 2.24 nm, PKS: 1.99 nm), and larger pore volume (CS: 0.34 cm3 g-1, PKS: 0.30 cm3 g-1) than the untreated activated carbon, demonstrating that the NaOH surface modification was efficient enough to improve the surface characteristics of the activated carbon. Moreover, surface modification via 25% NaOH greatly increases the active functional group of activated carbon, thereby directly increasing the adsorption capability of activated carbon (CS: 527.44 mg g-1, PKS: 627.03 mg g-1). By applying the NaOH post-treatment as the ultimate surface modification technique to the activated carbon derived from PKS and CS, a highly microporous structure was produced.
Fulltext Optimization of Micro-Pollutants' Removal from Wastewater Using Agricultural Waste-Derived Sustainable Adsorbent

Alhothali A, Haneef T, Mustafa MRU, Moria KM, Rashid U, Rasool K, et al.

Int J Environ Res Public Health, 2021 11 01;18(21).
PMID: 34770021 DOI: 10.3390/ijerph182111506

Water pollution due to the discharge of untreated industrial effluents is a serious environmental and public health issue. The presence of organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) causes worldwide concern because of their mutagenic and carcinogenic effects on aquatic life, human beings, and the environment. PAHs are pervasive atmospheric compounds that cause nervous system damage, mental retardation, cancer, and renal kidney diseases. This research presents the first usage of palm kernel shell biochar (PKSB) (obtained from agricultural waste) for PAH removal from industrial wastewater (oil and gas wastewater/produced water). A batch scale study was conducted for the remediation of PAHs and chemical oxygen demand (COD) from produced water. The influence of operating parameters such as biochar dosage, pH, and contact time was optimized and validated using a response surface methodology (RSM). Under optimized conditions, i.e., biochar dosage 2.99 g L-1, pH 4.0, and contact time 208.89 min, 93.16% of PAHs and 97.84% of COD were predicted. However, under optimized conditions of independent variables, 95.34% of PAH and 98.21% of COD removal was obtained in the laboratory. The experimental data were fitted to the empirical second-order model of a suitable degree for the maximum removal of PAHs and COD by the biochar. ANOVA analysis showed a high coefficient of determination value (R2 = 0.97) and a reasonable second-order regression prediction. Additionally, the study also showed a comparative analysis of PKSB with previously used agricultural waste biochar for PAH and COD removal. The PKSB showed significantly higher removal efficiency than other types of biochar. The study also provides analysis on the reusability of PKSB for up to four cycles using two different methods. The methods reflected a significantly good performance for PAH and COD removal for up to two cycles. Hence, the study demonstrated a successful application of PKSB as a potential sustainable adsorbent for the removal of micro-pollutants from produced water.
Waste to biodiesel: A preliminary assessment for Saudi Arabia

Rehan M, Gardy J, Demirbas A, Rashid U, Budzianowski WM, Pant D, et al.

Bioresour Technol, 2018 Feb;250:17-25.
PMID: 29153646 DOI: 10.1016/j.biortech.2017.11.024

This study presents a preliminary assessment of biodiesel production from waste sources available in the Kingdom of Saudi Arabia (KSA) for energy generation and solution for waste disposal issues. A case study was developed under three different scenarios: (S1) KSA population only in 2017, (S2) KSA population and pilgrims in 2017, and (S3) KSA population and pilgrims by 2030 using the fat fraction of the municipal solid waste. It was estimated that S1, S2, and S3 scenarios could produce around 1.08, 1.10 and 1.41 million tons of biodiesel with the energy potential of 43423, 43949 and 56493 TJ respectively. Furthermore, annual savings of US $55.89, 56.56 and 72.71 million can be generated from landfill diversion of food waste and added to the country's economy. However, there are challenges in commercialization of waste to biodiesel facilities in KSA, including waste collection and separation, impurities, reactor design and biodiesel quality.
Evaluating the Potential of Oleaginous Yeasts as Feedstock for Biodiesel Production

Mukhtar H, Suliman SM, Shabbir A, Mumtaz MW, Rashid U, Rahimuddin SA

Protein Pept Lett, 2018;25(2):195-201.
PMID: 29359654 DOI: 10.2174/0929866525666180122112805

BACKGROUND: Lipid-producing microorganisms, said to be oleaginous have been recognized since several years. We had investigated the effects of medium components and culturing situations on cell growth and lipid accumulation of oleaginous yeasts which were analytically examined so as to enhance lipid yield for biodiesel production.
OBJECTIVE: The main objective of this study was to explore oleaginous yeast, Yarrowia lipolytica isolated from soil and optimization of culture conditions and medium components to obtained better quality microbial oil for biodiesel production.
METHODS: Fifty yeast strains were isolated from soil from different regions of Lahore and eleven of them were selected for oil production. The isolated yeast colonies were screened to further check their lipid producing capabilities by the qualitative analysis. Five yeast strains were designated as oleaginous because they produced more than 16% of oil based on their biomass. To estimate the total lipid content of yeast cells, the extraction of lipids was done by performing the procedure proposed by Bligh and Dyer. The transesterification of yeast oils was performed by using different methods. There were three different strategies customized to transesterifying microbial oil using base catalyzed transesterification, acid catalyzed transesterification and enzyme-based transesterification. After completion of transesterification, sample was used for fatty acid methyl esters (FAMEs) were analyzed by gas-chromatograph with ionization detector type MS.
RESULTS: The isolate IIB-10 identified as Yarrowia lipolytica produced maximum amount of lipids i.e. 22.8%. More amount of biomass was obtained when cane molasses was utilized as carbon source where it produced 29.4 g/L of biomass while sucrose and lactose were not utilized by IIB-10 and no biomass was obtained. Similarly, meat extracts showed best results when it was used as nitrogen source because it resulted in 35.8 g/L biomass of Yarrowia lipolytica IIB-10. The culturing conditions like size of inoculum, effect of pH and time of incubation were also studied. The 10% of inoculum size produced 25.4 g/L biomass at 120 h incubation time, while the pH 7 was the optimum pH at which 24.8 g/L biomass was produced by Yarrowia lipolytica IIB-10. GC-MS analysis showed that biodiesel produced by transesterification contained similar fatty acids as found in vegetable oil for this reason it is widely accepted feedstock for biodiesel production.
CONCLUSION: The analysis of fatty acids methyl esters showed the similar composition of microbial oil as in vegetable oils and high amount of methyl esters were obtained after transesterification. Therefore, potentially oleaginous yeast could be used to generate a large amount of lipids for biodiesel production that will be the better substitute of petroleum-based diesel and will also control the environmental pollution.
Chemical Composition of Date Palm (Phoenix dactylifera L.) Seed Oil from Six Saudi Arabian Cultivars

Nehdi IA, Sbihi HM, Tan CP, Rashid U, Al-Resayes SI

J Food Sci, 2018 Mar;83(3):624-630.
PMID: 29377104 DOI: 10.1111/1750-3841.14033

This investigation aimed to evaluate the chemical composition and physicochemical properties of seed oils from 6 date palm (Phoenix. dactylifera L.) cultivars (Barhi, Khalas, Manifi, Rezeiz, Sulaj, and Sukkari) growing in Saudi Arabia and to compare them with conventional palm olein. The mean oil content of the seeds was about 7%. Oleic acid (48.67%) was the main fatty acid, followed by lauric acid (17.26%), stearic acid (10.74%), palmitic acid (9.88%), and linolenic acid (8.13%). The mean value for free fatty acids content was 0.5%. The P. dactylifera seed oil also exhibited a mean tocol content of 70.75 mg/100 g. α-Tocotrienol was the most abundant isomer (30.19%), followed by γ-tocopherol (23.61%), γ-tocotrienol (19.07%), and α-tocopherol (17.52%). The oils showed high thermal and oxidative stabilities. The findings indicate that date seed oil has the potential to be used in the food industry as an abundant alternative to palm olein.
PRACTICAL APPLICATION: This study showed that date seed had great nutritional value due to which it can be used for food applications especially as frying or cooking oil. In addition, date oil has also potential to be used in cosmetic and pharmaceutical practices as well. The extraction of oil from Phoenix dactylifera seed on large scale can create positive socioeconomic benefits especially for rural communities and could also assist to resolve the environmental issues generated by excess date production in large scale date-producing countries such as Saudi Arabia.
Fulltext Single-Pot Synthesis of Biodiesel using Efficient Sulfonated-Derived Tea Waste-Heterogeneous Catalyst

Rashid U, Ahmad J, Ibrahim ML, Nisar J, Hanif MA, Shean TYC

Materials (Basel), 2019 Jul 18;12(14).
PMID: 31323732 DOI: 10.3390/ma12142293

The main purpose of this manuscript is to report the new usage of tea waste (TW) as a catalyst for efficient conversion of palm fatty acid distillate (PFAD) to biodiesel. In this work, we investigate the potential of tea waste char as a catalyst for biodiesel production before and after sulfonation. The activated sulfonated tea waste char catalyst was characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), elemental composition (CHNS), nitrogen adsorption-desorption using Brunauer-Emmett-Teller (BET) and ammonia-temperature-programmed desorption (NH3-TPD). The activated tea waste char catalyst shows higher acid density of 31 μmol g-1 as compared to tea waste char of 16 μmol g-1 and higher surface area of 122 m2/g. The optimum fatty acid conversion conditions were found that 4 wt % of catalyst loading with 9:1 of methanol:PFAD for 90 min of reaction time at 65 °C gives 97% free fatty acid (FFA) conversion. In conclusion, the sulfonated tea waste (STW) catalyst showed an impressive catalytic activity towards the esterification of PFAD at optimum reaction conditions with significant recyclability in five successive cycles without any reactivation step.
Fulltext Characterization of bioadsorbent produced using incorporated treatment of chemical and carbonization procedures

Lee CL, H'ng PS, Chin KL, Paridah MT, Rashid U, Go WZ

R Soc Open Sci, 2019 Sep;6(9):190667.
PMID: 31598301 DOI: 10.1098/rsos.190667

The production of bioadsorbent from palm kernel shell (PKS) and coconut shell (CS) pretreated with 30% phosphoric acid (H3PO4) was optimized using the response surface methodology (RSM). Iodine adsorption for both bioadsorbents was optimized by central composite design. Two parameters including the H3PO4 pretreatment temperature and carbonization temperature were determined as significant factors to improve the iodine adsorption of the bioadsorbent. Statistical analysis results divulge that both factors had significant effect on the iodine adsorption for the bioadsorbent. From the RSM analysis, it was suggested that using 80 and 79°C as H3PO4 pretreatment temperature and 714 and 715°C as carbonization temperature would enhance the iodine adsorption of the CS and PKS bioadsobent, respectively. These results indicated that H3PO4 is a good pretreatment for preparing PKS and CS prior to carbonization process to produce bioadsorbent with well-developed microporous and mesoporous volume. The effort to produce alternative high grade and inexpensive adsorbent derived from lignocellulosic biomass, particularly in the nut shell form was implied in this research.
Low-cost novel nano-constructed granite composites for removal of hazardous Terasil dye from wastewater

Khalil M, Hanif MA, Rashid U, Ahmad J, Alsalme A, Tsubota T

Environ Sci Pollut Res Int, 2023 Jul;30(34):81333-81351.
PMID: 35710971 DOI: 10.1007/s11356-022-21367-8

The hazardous dyes on mixing with water resources are affecting many life forms. Granite stone is popular worldwide for decorating floors, making other forms of decorative materials and items. Granite stone powder waste can be obtained free of cost from marble factories as factories spend on the disposal of this waste. In the present study, novel granite stone powder waste composite has been prepared and utilized for the effective removal of Terasil dye. Two types of granite including gray granite and white granite were used in pure, calcinized, and chemically modified forms. Freundlich adsorption isotherm model best explained the adsorption mechanism of dye removal using granite composites as compared to other adsorption isothermal models. Characterization techniques like scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were used for the determination of morphological features and functional groups of granite composites. The obtained results were statistically analyzed using analysis of variance (ANOVA) along with the post hoc Tukey test. An extraordinarily high Terasil dye uptake capacity (more than 400 mg/g) was exhibited by granite composites prepared using sodium metasilicate. The synthesized novel nano-constructed composites provided a viable strategy as compared to the pure granite stone for dye removal from wastewater water.
Fulltext Unravelling trends, patterns and intellectual structure of research on bankruptcy in SMEs: A bibliometric assessment and visualisation

Rashid U, Abdullah M, Khatib SFA, Khan FM, Akhter J

Heliyon, 2024 Jan 30;10(2):e24254.
PMID: 38293348 DOI: 10.1016/j.heliyon.2024.e24254

Despite the burgeoning interest among academics in investigating the factors contributing to the high business failure rate among SMEs (small and medium-sized enterprises), the systematic synthesis of the literature on bankruptcy in SMEs is restricted. This article aims to significantly advance the understanding of the causes and repercussions of bankruptcy in SMEs and the preventative actions that may be taken to avoid it. This review assesses 282 articles from 175 outlets employing quantitative and statistics-based bibliometric tools. This bibliometric assessment helped delineate the citation and publication trends and the top contributors to the domain. The underlying thematic clusters of research on bankruptcy in SMEs were also identified, deciphered and elaborated, along with charting the future research vistas through the lens of theory, context, and methods framework. The authors believe this bibliometric variant of systematic literature review makes a significant contribution to bankruptcy and SME research by highlighting the development of the literature and some of the most active research fronts in the domain by offering insights that were not clasped thoroughly or assessed by prior literature assessments.
Synthesis and utilization of biomass-derived sulfonated heterogeneous catalyst-BT-SO3H for microalgal biodiesel production

Ao S, Rashid U, Shi D, Rokhum SL, Tg Thuy L, Awad Alahmadi T, et al.

Environ Res, 2024 Mar 15;245:118025.
PMID: 38151153 DOI: 10.1016/j.envres.2023.118025

The study investigates the potential of utilizing banana trunk-derived porous activated biochar enriched with SO3H- as a catalyst for eco-friendly biodiesel production from the microalga Chlorella vulgaris. An extensive analysis, employing advanced techniques such as XRD, FTIR, TGA, XPS, NH3-TPD, BET, SEM-EDX, and TEM, was conducted to elucidate the physicochemical properties of BT-SO3H catalysts. The synthesized catalyst demonstrated its efficiency in converting the total lipids of Chlorella vulgaris into biodiesel, with varying concentrations of 3%, 5%, and 7%. Notably, using a 5% BT-SO3H concentration resulted in remarkably higher biodiesel production about 58.29%. Additionally, the fatty acid profile of C. vulgaris biodiesel indicated that C16:0 was the predominant fatty acid at 24.31%, followed by C18:1 (19.68%), C18:3 (11.45%), and C16:1 (7.56%). Furthermore, the biodiesel produced via 5% BT-SO3H was estimated to have higher levels of saturated fatty acids (SFAs) at 34.28%, monounsaturated fatty acids (MUFAs) at 30.70%, and polyunsaturated fatty acids (PUFAs) at 24.24%. These findings highlight the promising potential of BT-SO3H catalysts for efficient and environmentally friendly biodiesel production from microalgal species.
Fulltext Green synthesis of silver nanoparticles through reduction with Solanum xanthocarpum L. berry extract: characterization, antimicrobial and urease inhibitory activities against Helicobacter pylori

Amin M, Anwar F, Janjua MRSA, Iqbal MA, Rashid U

Int J Mol Sci, 2012;13(8):9923-9941.
PMID: 22949839 DOI: 10.3390/ijms13089923

A green synthesis route for the production of silver nanoparticles using methanol extract from Solanum xanthocarpum berry (SXE) is reported in the present investigation. Silver nanoparticles (AgNps), having a surface plasmon resonance (SPR) band centered at 406 nm, were synthesized by reacting SXE (as capping as well as reducing agent) with AgNO(3) during a 25 min process at 45 °C. The synthesized AgNps were characterized using UV-Visible spectrophotometry, powdered X-ray diffraction, and transmission electron microscopy (TEM). The results showed that the time of reaction, temperature and volume ratio of SXE to AgNO(3) could accelerate the reduction rate of Ag(+) and affect the AgNps size and shape. The nanoparticles were found to be about 10 nm in size, mono-dispersed in nature, and spherical in shape. In vitro anti-Helicobacter pylori activity of synthesized AgNps was tested against 34 clinical isolates and two reference strains of Helicobacter pylori by the agar dilution method and compared with AgNO(3) and four standard drugs, namely amoxicillin (AMX), clarithromycin (CLA), metronidazole (MNZ) and tetracycline (TET), being used in anti-H. pylori therapy. Typical AgNps sample (S1) effectively inhibited the growth of H. pylori, indicating a stronger anti-H. pylori activity than that of AgNO(3) or MNZ, being almost equally potent to TET and less potent than AMX and CLA. AgNps under study were found to be equally efficient against the antibiotic-resistant and antibiotic-susceptible strains of H. pylori. Besides, in the H. pylori urease inhibitory assay, S1 also exhibited a significant inhibition. Lineweaver-Burk plots revealed that the mechanism of inhibition was noncompetitive.
Fulltext Retraction notice to "Goat milk enhances memory of d-galactose-induced aging rats" [J Tradit Complement Med 11 (2021) 117-122]

Safdar A, Azman KF, Zakaria R, Ab Aziz CB, Rashid U

J Tradit Complement Med, 2021 Jul;11(4):381.
PMID: 34195033 DOI: 10.1016/j.jtcme.2021.06.003

[This retracts the article DOI: 10.1016/j.jtcme.2020.02.005.].
Transesterification reaction for synthesis of palm-based ethylhexyl ester and formulation as base oil for synthetic drilling fluid

Abdul Habib NS, Yunus R, Rashid U, Taufiq-Yap YH, Abidin ZZ, Syam AM, et al.

J Oleo Sci, 2014;63(5):497-506.
PMID: 24717547

The use of vegetable oil-based ester as a base fluid in synthetic drilling fluid has become a trend in drilling operations due to its environmental advantages. The transesterification reaction of palm oil methyl ester (POME) with 2-ethylhexanol (2EH) produced 98% of palm oil-based ethylhexyl ester in less than 30 minutes. Since the transesterification reaction of POME with 2EH is a reversible reaction, its kinetics was studied in the presence of excess EH and under vacuum. The POME-to-EH molar ratio and vacuum pressure were held constant at 1:2 and 1.5 mbar respectively and the effects of temperature (70 to 110°C) were investigated. Using excess of EH and continual withdrawal of methanol via vacuum promoted the reaction to complete in less than 10 minutes. The rate constant of the reaction (k) obtained from the kinetics study was in the range of 0.44 to 0.66 s⁻¹ and the activation energy was 15.6 kJ.mol⁻¹. The preliminary investigations on the lubrication properties of drilling mud formulated with palm oil-based 2EH ester indicated that the base oil has a great potential to substitute the synthetic ester-based oil for drilling fluid. Its high kinematic viscosity provides better lubrication to the drilling fluid compared to other ester-based oils. The pour point (-15°C) and flash point (204°C) values are superior for the drilling fluid formulation. The plastic viscosity, HPHT filtrate loss and emulsion stability of the drilling fluid had given acceptable values, while gel strength and yield point could be improved by blending it with proper additives.

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