Shikimic acid (SA) is a valuable compound found in water hyacinth and is a precursor for synthesis of antiviral drug oseltamivir phosphate (Tamiflu®) which is used to treat H5N1 avian influenza. In ...the present work, the acid was extracted from different morphological parts (stem, leaves, and roots) of water hyacinth (a notorious aquatic weed) using sonication. The parametric study has been conducted by varying sonication time (10–50 min), solvent composition (methanol + water), solvent volume (20–50 mL), amplitude of sonication (30–60%), and pulse ratio (20–50%) for improving the recovery of shikimic acid (SA), antioxidant activity (AA) and total phenolic content (TPC) of water hyacinth extract. Also, the acid was extracted conventionally as a benchmark study. The highest yield of 2.4% at 40 min and 3.1% at 30 min was observed in case of conventional and ultrasound assisted extraction (UAE), respectively for stem. Leaves showed a higher TPC value of 7.4 mg GAE/g biomass and a higher AA was observed 83.21% at 20 min for stem in case of conventional method. The highest TPC value of 11.11 mg GAE/g biomass has been observed for leaves while stem has shown the highest AA of 87.72% at 10 min of sonication time for UAE. It was possible to recover the valuable chemicals with better processing conditions in the case of UAE.
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•Water hyacinth: Proliferative aquatic weed having ecological issues.•Shikimic acid (SA): Present in water hyacinth and in demand to synthesize Tamiflu®.•Responses: SA yield, Phenolic content in extract, Antioxidant activity of extract.•Extraction in presence of sonication using parametric study.•Eco-friendly solvent (Water) has yielded the highest recovery.
The present study reports for the first time the production of the known compound camptothecin and its derivatives by the plant
Apodytes dimidiata. Further, two fungal endophytic strains isolated ...from the same plant
, have also been demonstrated to produce camptothecin and its derivatives, 10-hydroxycamptothecin and 9-methoxycamptothecin under in vitro conditions.
Camptothecin and 10-hydroxycamptothecin are two important precursors for the synthesis of the clinically useful anticancer drugs, topotecan and irinotecan. In recent years, efforts have been made to identify novel plant and endophytic fungal sources of camptothecin and 10-hydroxycamptothecin. In this study we have isolated endophytic fungi strains from
Apodytes dimidiata (Icacinaceae), a medium sized tree from the Western Ghats, India. The fungi were identified as
Fusarium solani using both ITS rDNA sequencing and spore morphology. Two strains, MTCC 9667 and MTCC 9668 were isolated, both of which produced camptothecin and 9-methoxycamptothecin in their mycelia; one of the strains, MTCC 9668 also produced 10-hydroxycamptothecin, though in small amounts. The yields of camptothecin in MTCC 9667 and MTCC 9668 were 37 and 53
μg/100
g, respectively, after 4
days of incubation in broth culture. The yields of 10-hydroxycamptothecin and 9-methoxycamptothecin in MTCC 9668 were 8.2 and 44.9
μg/100
g, respectively. Further research in optimizing the culture conditions of these fungal strains might permit their application for the production of camptothecin and 10-hydroxycamptothecin.
This paper describes the results of experiments on dehydrogenation of methylcyclohexane over Pt supported on metal oxides (Pt/MO) and Pt supported on perovskite (Pt/Per) catalysts. The reaction is ...being considered as a means for delivery of hydrogen to fueling stations in the form of more easily transportable methylcyclohexane. Among Pt/MO catalysts, the best activity as determined by the hydrogen evolution rate was observed over Pt/La
2O
3 catalyst at 21.1 mmol/g
met/min. Perovskite-supported catalysts exhibited relatively higher activity and selectivity, with Pt/La
0.7Y
0.3NiO
3 giving the best performance. This Pt/Per catalyst had an activity of ca 45 mmol/g
met/min with nearly 100% selectivity towards dehydrogenation. The catalysts were characterized using XRD, CO-chemisorption and SEM-EDXA techniques. The present study reports catalysts that minimize the use of Pt and explores tailoring the properties of the perovskite structure.
This study contains a two-dimensional mathematical model of solute transport in a river with temporally and spatially dependent flow, explicitly focusing on pulse-type input point sources with a ...fractional approach. This model is analyzed by assuming an initial concentration function as a declining exponential function in both the longitudinal and transverse directions. The governing equation is a time-fractional two-dimensional advection–dispersion equation with a variable form of dispersion coefficients, velocities, decay constant of the first order, production rate coefficient for the solute at the zero-order level, and retardation factor. The solution of the present problem is obtained by the fractional reduced differential transform method (FRDTM). The analysis of the initial retardation factor has been carried out via plots. Also, the influence of initial longitudinal and transverse dispersion coefficients and velocities has been examined by graphical analysis. The impact of fractional parameters on pollution levels is also analyzed numerically and graphically. The study of convergence for the FRDTM technique has been conducted to assess its efficacy and accuracy.
Shikimic acid (SA) is a valuable compound found in water hyacinth. Also, water hyacinth is a rich source of lignocellulosic material. In the present study, conventional extraction was employed for ...recovering SA from the stem of the weed by varying parameters such as stirring time, solvent volume, temperature and solvent composition. The highest yield of SA (2.48%) was obtained using 20 mL water at 30 °C for 40 min. For extraction of lignin and cellulose from the residual water hyacinth, an organosolv (using 80% ethanol) and alkali treatment have been used to isolate lignin and cellulose, respectively. The lignin content has been found to be 16% in the stem of water hyacinth whereas in pulp from organosolv process it was 9% when treated with sulphuric acid. The highest yield of lignin (7%) and cellulose (31%) were obtained at 210 °C and 36 bar while employing organosolv process. Alkali treatment of water hyacinth stem with 8% NaOH was carried out in an autoclave at 120 °C and 160 °C, and 21.87% of lignin was recovered at 160 °C and 5 bar. Characterization of lignin and cellulose using FT-IR and TGA has confirmed their resemblance with data reported in the literature. Thus, the present study was aimed to utilize the water hyacinth with minimum waste generation and thereby achieving the sustainable solution.
Graphical abstract
In this research, we analyze the non-linear time-fractional Kudryashov–Sinelshchikov equation, which represents waves induced by pressure inside the combination of gas bubbles and liquid, considering ...heat transfer and viscidness of liquid among gas bubbles and liquid. The non-linear Kudryashov–Sinelshchikov equation having fractional order is numerically solved employing the fractional reduced differential transform method (FRDTM). We have conducted a convergence analysis of the solution series obtained through FRDTM. Also, the FRDTM generates the solution without perturbation, discretization, or linearization. The numerical solution and error analysis of this non-linear Kudryashov–Sinelshchikov equation having fractional order with respect to time using FRDTM completely conforms with the exact solution as shown precisely in 2D and 3D graphs. The results of this research demonstrate the effectiveness and accuracy of the FRDTM in solving the non-linear time-fractional Kudryashov–Sinelshchikov equation.
The focus of this paper is the study of mathematical model for the analysis of diffusion and transport processes of chemicals in river systems. In the present study, we have introduced a ...one-dimensional model that is described by time-dependent convection-diffusion differential equations. The focus of our study is the potential pollution of the river, both with and without a specific pollution source. The current investigation aims to analyze the impact of two different input source functions, namely constant and linear forms. In order to validate the model, we conducted a study on the diffusion and transport of chemicals, specifically focusing on NO_3 and PO_4 of the Tapi river. Reduced differential transform method (RDTM) is used to obtain solutions. For the accuracy of the solution, the convergence of solution function is examined in each case obtained from RDTM. The pollutant concentration at various distances and time levels has been shown numerically and graphically in each case. The pollution levels with and without sources are compared in 2D and 3D graphs. The methodology proposed in this study for river pollution prediction using a 1D pollution model can be applied to other rivers.
•TF-GBFE combines the reaction, advection, and dissipation mechanisms.•TF-GBFE is used in applied sciences and physical applications, including, fluid mechanics, ocean engineering, etc.•The ...time-fractional generalized Burger–Fisher equation (TF-GBFE)” is a highly non-linear PDE.•Solution for TF-GBFE has been investigated with fractional reduced differential transform method.•The physical behavior of the obtained solutions has been captured in terms of 3-D graphs for diverse fractional order.•Obtained solutions for order α=1 have been compared with exact solutions graphically.
‘‘The time-fractional generalized Burger–Fisher equation (TF-GBFE)” is used in various applied sciences and physical applications, including simulation of gas dynamics, financial mathematics, fluid mechanics, and ocean engineering. This equation represents a concept for the coordination of reaction systems, as well as advection, and conveys the understanding of dissipation. The Fractional Reduced Differential Transform Method (FRDTM) is used to evaluate “the time-fractional generalized Burger–Fisher equation (TF-GBFE).” To determine the method’s validity, when the solutions are obtained, they are correlated to exact solutions of α=1 order, and even for various values of α. Three-dimensional graphs are used to depict the solutions. Additionally, the analysis of exact and FRDTM solutions indicates that the proposed approach is very accurate.
Since hydrogen is produced by reforming of hydrocarbon it contains carbon monoxide (CO). In order to make hydrogen suitable for proton exchange membrane fuel cell application there is need to reduce ...concentration of CO less than 100 ppm. Water–Gas-Shift reactions subsequent to reforming lower CO concentration in H2 to about 1–1.5% by volume. Preferential oxidation of CO (PROX–CO) using a catalyst is therefore important for further cleaning up of CO from H2. The catalyst in this study is platinum supported over lanthanum ferrite–ceria (Pt/LaFeO3–CeO2) exhibits excellent activity of 99.8% and selectivity of 95.7% at a relatively lower temperature of 100 °C with an equivalence ratio of 3 for PROX–CO. The concentration of CO is reduced from 1% v/v in feed to ca. 30 ppm in product gas with relatively lower loss of hydrogen is the most significant achievement in this study. The catalyst is selective towards CO oxidation as the hydrogen loss is relatively low (ca. 3.8%) and there is no methane formation. The improvement in catalytic activity and selectivity is attributed to the strong metal support interaction and open morphology of catalyst. The results obtained in this study reveal the excellent catalytic activity by using LaFeO3–CeO2 as support for Pt catalyst.
The Pt supported over LaFeO3–CeO2 exhibits the CO conversion in the range of 99% and the selectivity for CO conversion is in the range of 93–96%. The catalyst measurably lowers are the CO concentration to the extent of 30 ppm from the CO concentration of 1% v/v present in the reactant gas of PROX–CO. The results are most promising for cleaning of hydrogen for fuel cell applications. Display omitted
► Chitosan complex method resulted in LaFeO3 with pure phase, crystalline, open porous morphology and higher surface area. ► Higher CO conversion in the range of 99% and selectivity for CO conversion in the range of 93–96%. ► Minimization of CO concentration in hydrogen to the extent of 30 ppm by PROX–CO reaction. ► Synergistic effect observed for PROX–CO activity using LaFeO3 and CeO2 as support for Pt catalyst.
Background and objectiveButter coffee drinks, mainly a form of a saturated fat diet, are widely accepted as a "healthy energy-boosting drink", especially in the young and healthy military population. ...The objective of our study was to determine the effects of medium-chain triglyceride (MCT) oil and butter on lipid profile, especially apolipoprotein B (ApoB), low-density lipoprotein (LDL)-cholesterol (LDL-C), high-density lipoprotein (HDL)-cholesterol (HDL-C), and other risk factors for coronary heart disease, such as BMI, BP, fasting blood glucose, HbA1c, and high-sensitivity C-reactive protein (hs-CRP) levels in healthy adults.Materials and methodsWe conducted a prospective study of 60 subjects who were randomized to one of the two following regimens: (1) coffee or (2) coffee with butter plus MCT oil combination. The primary outcome was the effect on ApoB. Secondary outcomes were as follows: non-HDL-C, LDL-C, triglycerides, BP, waist circumference, fasting blood glucose, and HbA1c. These parameters were evaluated at the baseline and after 12 weeks. The Mann-Whitney U test was utilized for analysis of the results.ResultsWhile 60 subjects were recruited for the study, only 41 completed it, meeting the minimum required sample size (17 per group) necessary to achieve the desired effect size: 21 males (nine in the control group and 12 in the experimental group) and 20 females (10 in each group). Anthropometric measures were similar between the two groups at baseline, and so were age and BMI (average age: 33.00 ± 5.84 years among controls and 30.86 ± 6.14 years in the experimental group; BMI: 27.35 ± 4.63 kg/m2 vs. 25.74 ± 2.70 kg/m2). The pulse rate was 69.35 ± 10.98 in the control vs. 70.68 ± 10.32 bpm in the experimental group. The waist size was also similar in both groups. Baseline lab findings were as follows: ApoB: 89.85 ± 17.52 (control), 81.60 ± 12.84 mg/dL (experimental); hs-CRP: 0.18 ± 0.27 (control), 0.17 ± 0.27 mg/L (experimental); LDL-C 113.65 ±23.71 (control), 106.50 ± 18.99 mg/dL (experimental); HDL-C 57.35 ± 14.63 (control), 62.41 ± 16.15 mg/dL (experimental); and triglycerides: 76.00 ± 31.30 (control), 56.77 ± 14.77 mg/dL (experimental), and these values were similar. The values after 12 weeks of intervention were as follows: BMI: 27.37 ± 5.24 (control), 26.36 ± 3.55 (experimental); pulse rate: 78.88 ± 14.00 (control), 74.20 ± 11.90 bpm (experimental); ApoB 87.1 ± 17.38 (control), 85.7 ±20.59 mg/dL (experimental); hs-CRP 0.26 ± 0.22 (control), 0.15 ± 0.14 mg/L (experimental); LDL-C 111.59 ± 20.35 (control), 114.10 ± 26.99 mg/dL (experimental); HDL-C 57.71 ± 12.93 (control), 64.85 ± 13.32 mg/dL (experimental); and triglycerides: 74.71 ± 25.39 (control), 60.80 ± 15.77 mg/dL (experimental).ConclusionAt a significance level of 5%, there was no difference between the two groups, either at the baseline or at 12 weeks of intervention. Based on our findings, adding MCT oil and butter to coffee may be safe. However, further studies with larger sample sizes and longer duration are needed to validate our findings.
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