Cyclic voltammetry and reduction mechanistic studies of styrylpyrylium perchlorates

The reduction and oxidation potentials of methylated 4-styrylpyrylium and 6-styrylpyrylium perchlorates have been evaluated using cyclic voltammetry, in comparison to their non-methylated derivatives values. The reduction peak of all studied compounds remained chemically irreversible. The presence of the electron-donating methyl group on pyrylium ring leads to a shift of the styrylpyrylium perchlorates reduction potential towards cathodic values. Kinetic studies on platinum electrodes based on the variation of the peak potential at different scan rates and upon substrate concentrations confirm, in another way, the mechanism of electron transfer. KEY WORDS: Styrylpyrylium perchlorates, Cyclic voltammetry, Reduction potential, Kinetic study Bull. Chem. Soc. Ethiop. 2013, 27(1), 117-124.DOI: http://dx.doi.org/10.4314/bcse.v27i1.1

Biological and phytochemical investigations of extracts from Pterocarpus erinaceus Poir (Fabaceae) root barks

Background: Pterocarpus erinaceus Poir. belonging to Fabacae familly is used as medicinal plant in Burkina Faso’s folk medicine. Roots of P. erinaceus are used to treat ulcer, stomach ache and inflammatory diseases. The objective of the present study was to carry out phytochemical composition of methanol (MeOH) and dichloromethane (DCM) extracts from Pterocarpus erinaceus roots, to isolate pure compounds, and to evaluate their pharmacological activities.Methods: Chromatographic fractionation led to the isolation of active components of the extracts. The structures were established by NMR analysis and comparison with data from literature. The anti-inflammatory activity was evaluated using croton oil-induced edema of mice ear as well as the effect of extracts against lipoxygenase and lipid peroxidation was evaluated. 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Cupric-reducing antioxidant capacity (CUPRAC) methods were used to evaluate the antioxidant activity of the extracts.Results: Friedelin (1), 3α-hydroxyfriedelan-2-one (2), α-sophoradiol (3) and stigmasterol (4) were isolated from DCM extract and maltol-6-O-apiofuranoside-glucopyranoside (5) isolated from MeOH. DCM extract and friedelin, 3α-hydroxyfriedelan-2-one, α- sophoradiol showed a significant anti-inflammatory effect against ear edema. Friedelin (1), α-sophoradiol (3) and maltol-6-O-apiofuranoside-glucopyranoside (5) exhibited lipoxygenase inhibition. MeOH extract (100 μg/mL) inhibited lipoxygenase and lipid peroxidation activities at 45.1 ± 3% and 30.7 ± 0.5% respectively. MeOH extract, ethyl acetate fraction and butanol fraction exhibited antioxidant property with both two methods used.Conclusion: The results suggested that the extracts and compounds from roots of Pterocarpus erinaceus possessed local antiinflammatory effect, antioxidant properties and inhibitor effect against lipoxygenase and lipid peroxidation activities.Keywords: Pterocarpus erinaceus, triterpenes, anti-inflammatory, antioxidant, lipoxygenas

Quality control and standardization of FACA® syrup

Sickle cell disease is a major public health problem. It is the first genetic disease in the world. FACA syrup offers an alternative treatment. It is a dry powder preparation of two components, the roots barks of Zanthoxylum zanthoxyloides Lam. (Rutaceae) Zepernick, Timler and Calotropis procera. Ait. R.B.r. (Asclepiadaceae). The product was developed at Institute for Research in Health Sciences (IRSS) from a traditional recipe used in Burkina Faso for treatment of sickle cell crises. This study aimed to establish physical-chemical, pharmaco technical and microbiological control parameters essential for the standardization of the phytomedicine. This valuation concerned specifications of moisture content, pH, the fingerprint by thin layer chromatography, pesticide residues, heavy metal content, microbial quality, and total ash. These charcteristics were determined by the methods prescribed by the World Health Organization (1998) and the European Pharmacopoeia 6th edition. The results have shown that dry syrups and reconstituted syrups were sweet, slightly spicy with a bitter after taste, a white room color and a faint odor. The density at the preparation was 0.985 and the pH was 5.93. After 2 months of storage in the laboratory, the organoleptic parameters of the reconstituted syrups have not changed. They were mold free, the density remained around 1 and the pH between 5 and 4. These parameters have shown that the quality of plants powders and these medicine comply with the recommendations of the European pharmacopoeia. Faca syrup may contribute to the better management of sickle cell disease in children

Preparedness of Healthcare Workers towards Handling COVID-19 Outbreak in the Gambia

Background: The novel Coronavirus (COVID-19) outbreak that began in Wuhan, China rapidly became a public health concern and a challenge for healthcare systems globally.  In the wake of the first confirmed case in The Gambia, concerns were raised in some quarters about the health system's preparedness to handle the outbreak. Therefore, we aimed to assess health personnel's knowledge and preparedness in fighting the COVID-19 outbreak in The Gambia. Methods: A cross-sectional survey was conducted using self-administered questionnaires distributed online through social media. Descriptive, bivariate, and binary logistic analyses were done using SPSS Version 22. Results: We obtained 333 valid responses. Most participants reported that their health facility has some form of preparedness; however, only a small proportion reported enough PPEs in the health facility. About half (50.5%) showed good knowledge of COVID-19. There was a statistically significant difference among the professions regarding their reaction if they were found positive of COVID-19 (p=0.006). There was a significant association between health professions [other professions (Odds ratio [OR]=0.2, 95% Confidence interval [CI]:0.04–0 .9; p=0.038)] and overall knowledge of COVID-19. Conclusion: Our findings showed some form of preparedness towards COVID-19 among healthcare workers. However, many aspects, such as the availability of PPEs and their proper use and knowledge, need improvement. Thus, training and an adequate supply of equipment are required to better respond to upcoming COVID-19 waves and future outbreaks.   Doi: 10.28991/SciMedJ-2021-03-SI-5 Full Text: PD

Styrylpyrylium Salts: 1H and 13C NMR High-Resolution Spectroscopy (1D and 2D)

1H and 13C NMR high-resolution spectroscopy (1D and 2D) (1H, 1H-COSY, HSQC, HMBC) for four styrylpyrylium perchlorates were carried out and signal attributions are reported. Chemical shifts observed on 13C NMR spectra for the styrylpyrylium salts were compared with net atomic charge for carbon obtained by AM1 semiempirical calculations. The position of the styryl group present low effect on chemical shifts for carbon atoms, while the presence of methyl group led to the unshielding of the substituted carbon

Enhanced extraction of flavonoids from Odontonema strictum leaves with antioxidant activity using supercritical carbon dioxide fluid combined with ethanol

Flavonoids were extracted from Odontonema strictum leaves by supercritical carbon dioxide, with ethanol. The effect of three independents variables (time, pressure and temperature) on the Total Flavonoid Content (TFC) were optimized by factorial investigation. The TFC and flavonoid recovery varies respectively from 99.33 to 247.78 mg/g of dried extract and 10.68–18.92 mg/g of dried leaves powder, while the conventional solvent extraction (CSE) yielded 36.45 mg/g and 3.13 mg/g. Analysis of the factorial identified the optimal conditions with an extraction time of 270 min and a pressure of 200 bar, the temperature had no effect within the tested ranges. The predicted TFC was 203.11 mg/g under optimal conditions and experimentally 230.48 mg/g. The antioxidant activity with 2,2-Diphenyl-1-picrylhydrazyl method of the extracts under optimum conditions was 49.21% while the CSE extract was 37.05%. The TLC analysis of the supercritical fluid extracts from the optimum conditions showed 5 majors flavonoids

The effect of dosing strategies on the therapeutic efficacy of artesunate-amodiaquine for uncomplicated malaria : a meta-analysis of individual patient data

Background: Artesunate-amodiaquine (AS-AQ) is one of the most widely used artemisinin-based combination therapies (ACTs) to treat uncomplicated Plasmodium falciparum malaria in Africa. We investigated the impact of different dosing strategies on the efficacy of this combination for the treatment of falciparum malaria. Methods: Individual patient data from AS-AQ clinical trials were pooled using the WorldWide Antimalarial Resistance Network (WWARN) standardised methodology. Risk factors for treatment failure were identified using a Cox regression model with shared frailty across study sites. Results: Forty-three studies representing 9,106 treatments from 1999-2012 were included in the analysis; 4,138 (45.4%) treatments were with a fixed dose combination with an AQ target dose of 30 mg/kg (FDC), 1,293 (14.2%) with a non-fixed dose combination with an AQ target dose of 25 mg/kg (loose NFDC-25), 2,418 (26.6%) with a non-fixed dose combination with an AQ target dose of 30 mg/kg (loose NFDC-30), and the remaining 1,257 (13.8%) with a co-blistered non-fixed dose combination with an AQ target dose of 30 mg/kg (co-blistered NFDC). The median dose of AQ administered was 32.1 mg/kg [IQR: 25.9-38.2], the highest dose being administered to patients treated with co-blistered NFDC (median = 35.3 mg/kg [IQR: 30.6-43.7]) and the lowest to those treated with loose NFDC-25 (median = 25.0 mg/kg [IQR: 22.7-25.0]). Patients treated with FDC received a median dose of 32.4 mg/kg [IQR: 27-39.0]. After adjusting for reinfections, the corrected antimalarial efficacy on day 28 after treatment was similar for co-blistered NFDC (97.9% [95% confidence interval (CI): 97.0-98.8%]) and FDC (98.1% [95% CI: 97.6%-98.5%]; P = 0.799), but significantly lower for the loose NFDC-25 (93.4% [95% CI: 91.9%-94.9%]), and loose NFDC-30 (95.0% [95% CI: 94.1%-95.9%]) (P < 0.001 for all comparisons). After controlling for age, AQ dose, baseline parasitemia and region; treatment with loose NFDC-25 was associated with a 3.5-fold greater risk of recrudescence by day 28 (adjusted hazard ratio, AHR = 3.51 [95% CI: 2.02-6.12], P < 0.001) compared to FDC, and treatment with loose NFDC-30 was associated with a higher risk of recrudescence at only three sites. Conclusions: There was substantial variation in the total dose of amodiaquine administered in different AS-AQ combination regimens. Fixed dose AS-AQ combinations ensure optimal dosing and provide higher antimalarial treatment efficacy than the loose individual tablets in all age categories