Determination of favipiravir in human plasma using homogeneous liquid–liquid microextraction followed by HPLC/UV

Background: Favipiravir is an antiviral drug that was recently approved for the management of COVID-19 infection. Aim: This work aimed to develop a new method, using sugaring-out induced homogeneous liquid–liquid microextraction followed by HPLC/UV for the determination of favipiravir in human plasma. Materials & methods: The optimum extraction conditions were attained using 500 μl of tetrahydrofuran as an extractant and 1400 mg of fructose as a phase-separating agent. Results: The developed method was validated according to the US FDA bioanalytical guidelines and was found linear in the range of 25-80,000 ng/ml with a correlation coefficient of 0.999. Conclusion: These results showed that the developed method was simple, easy, valid and adequately sensitive for determination of favipiravir in plasma for bioequivalence studies.

Mathematical Modeling of Extraction of Neodymium using Pseudo-emulsion based Hollow Fiber Strip Dispersion (PEHFSD)

Pseudo-emulsion based hollow fiber strip dispersion (PEHFSD) is a promising alternative technique due to its stability, simplicity and cost of operation. This is an efficient process due to its high surface area for extraction as well as stripping, and low energy consumption for creating the pseudo-emulsion and for the separation of phases. This technique takes the combine advantages of emulsion liquid membrane and overcomes the sufferings of membrane stability in the supported liquid membrane systems. Present work includes extraction of neodymium (III) (Nd) by using TODGA and HNO3 as the extractant cum strippant in PEHFSD technique. A model is developed to study the transport of Nd under different hydrodynamic and chemical conditions that includes organic ratio (A/O) in dispersion, effect of speed of impeller on drop size formation, effect of feed acidity, effect of carrier concentration, effect of feed flow rate. A code is written to solve the model equations numerically to predict the concentration of the feed reservoir with time. Experiments are conducted to obtain the best optimum extraction conditions. Results obtained from the numerical simulations are validated with the experimental data and found a good agreement between them.

Bioactive Compounds from Ephedra fragilis: Extraction Optimization, Chemical Characterization, Antioxidant and AntiGlycation Activities

Response surface methodology (RSM) with a Box–Behnken design (BBD) was used to optimize the extraction of bioactive compounds from Ephedra fragilis. The results suggested that extraction with 61.93% ethanol at 44.43 °C for 15.84 h was the best solution for this combination of variables. The crude ethanol extract (CEE) obtained under optimum extraction conditions was sequentially fractionated with solvents of increasing polarity. The content of total phenolic (TP) and total flavonoid (TF) as well as the antioxidant and antiglycation activities were measured. The phytochemical fingerprint profile of the fraction with the highest activity was characterized by using RP-HPLC. The ethyl acetate fraction (EAF) had the highest TP and TF contents and exhibited the most potent antioxidant and antiglycation activities. The Pearson correlation analysis results showed that TP and TF contents were highly significantly correlated with the antioxidant and antiglycation activities. Totally, six compounds were identified in the EAF of E. fragilis, including four phenolic acids and two flavonoids. Additionally, molecular docking analysis also showed the possible connection between identified bioactive compounds and their mechanisms of action. Our results suggest new evidence on the antioxidant and antiglycation activities of E. fragilis bioactive compounds that may be applied in the treatment and prevention of aging and glycation-associated complications.

OPTIMIZATION OF PHENOLIC COMPOUNDS EXTRACTION FROM PURPLE BASIL LEAF BY CONVENTIONAL AND MICROWAVE ASSISTED EXTRACTION METHOD

The present study aimed to determine the optimum extraction conditions of conventional solvent extraction (CSE) and microwave-assisted extraction (MAE) techniques to obtain maximum total phenolic (TPC), total flavonoid (TFC), total anthocyanin (TAC) and antioxidant capacity (AA). Response surface methodology (RSM) and central composite design (CCD) were used to determine optimum points of CSE and MAE. Both two extraction methods, all parameters significantly affected TPC, AA, TFC and TAC (p<0.05). MAE showed higher bioactive compounds yield than that of CSE. Optimum point for CSE and MAE was found to be 60°C and 30 min and 591.83 W and 2.98 min respectively. TPC, AA, TFC and TAC were obtained as 33.81mg/g, 160.27 mg/g, 11.89 mg/g and 331.01 mg/kg for CSE and 62.99 mg/g, 214.62 mg/g, 21.80 mg/g and 3462.93 mg/kg for MAE respectively. This study recommended that the MAE should be used for the extraction of PBL to increase phenolic extraction yield.

Optimum Parameters for Extracting Three Kinds of Carotenoids from Pepper Leaves by Response Surface Methodology

To determine the optimum parameters for extracting three carotenoids including zeaxanthin, lutein epoxide, and violaxanthin from pepper leaves by response surface methodology (RSM), a solvent of acetone and ethyl acetate (1:2) was used to extract carotenoids with four independent factors: ultrasound time (20–60 min); ratio of sample to solvent (1:12–1:4); saponification time (10–50 min); and concentration of saponification solution (KOH–methanol) (10–30%). A second-order polynomial model produced a satisfactory fitting of the experimental data with regard to zeaxanthin (R2 = 75.95%, p < 0.0197), lutein epoxide (R2 = 90.24%, p < 0.0001), and violaxanthin (R2 = 73.84%, p < 0.0809) content. The optimum joint extraction conditions of zeaxanthin, lutein epoxide, and violaxanthin were 40 min, 1:8, 32 min, and 20%, respectively. The optimal predicted contents for zeaxanthin (0.823022 µg/g DW), lutein epoxide (4.03684 µg/g dry; DW—dry weight), and violaxanthin (16.1972 µg/g DW) in extraction had little difference with the actual experimental values obtained under the optimum extraction conditions for each response: zeaxanthin (0.8118 µg/g DW), lutein epoxide (3.9497 µg/g DW), and violaxanthin (16.1590 µg/g DW), which provides a theoretical basis and method for cultivating new varieties at low temperatures and weak light resistance.

Assessment of colour and tannin extraction in Tempranillo and Cabernet-Sauvignon using small-scale fermentation vessels

Researchers typically perform winemaking experiments using small volumes of grapes. This study examined which small-vessel volume (10, 25, 50 and 100 L) gives better repeatability during red winemaking extraction of colour and tannin in research studies. Few studies have actually evaluated the repeatability of small-scale fermentations using two varieties of different phenolic potential: Tempranillo and Cabernet-Sauvignon. We investigated how volume size may affect the composition of colour and tannins for these two varieties and result in potentially different phenolic contents. Furthermore, for each variety, we compared the small scale vessel with a commercial fermentation using a 2.500 L capacity. 50 L tanks resulted in optimum extraction of phenols and colour. High repeatability was observed for alcohol content, pH and total acidity, anthocyanins, and procyanidins for both varieties amongst vessel sizes. Kinetics of fermentation performed faster in big berry driven grapes (Tempranillo) regardless of the volume. Instead, for small berry grapes (Cabernet-Sauvignon), vessel size affected the kinetics or fermentation and therefore the extraction can be altered. Very high repeatability for the alcohol by volume, pH and total acidity (CV ≤ 7 %) as well as anthocyanins and procyanidins by HPLC (15 % ≤ CV ≤ 20 %) for both varieties in all volume sizes. This research provides a solid basis for validating the reproducibility of small-scale fermentations of two red grapevines with different phenolic potential and sheds new light on the potential and limitations of small-scale winemaking.

DETERMINATION OF THE OPTIMUM CONDITIONS FOR UREASE INHIBITTION EXTRACTED FROM SOME LOCAL PLANTS

In the current study, four types of plants commonly used namely Soybean, chickpea, bean, pea were obtained and screened for urease activity, among this plants, chickpea was chosen with maximum enzymatic activity, and it had the highest productivity of urease enzyme (1243 U/mg protein). Also sodium acetate buffer (0.2 M, pH 5.0) was chosen as a best extraction buffer with specific activity 1460 U/mg protein. The optimum extraction ratio represented by 1:8 (w:v) after 15 min, it was given 1988 U/mg protein. As well as four types of plants include garlic, red onion, green onion and cabbage were used to select the optimum plant material that inhibited urease enzyme. Cabbage was chosen, it had the highest inhibition activity of the enzyme (41%). Also tris buffer (0.2 M, pH 9) was selected as a best extraction buffer of plants inhibitor with inhibition activity 80%. The optimum extraction ratio represented by 1:8 (w:v) after 60 min, it was given 86% enzyme inhibition activity.

Preliminary Investigation of Different Drying Systems to Preserve Hydroxytyrosol and Its Derivatives in Olive Oil Filter Cake Pressurized Liquid Extracts

Phenolic compounds present in extra virgin olive oil (EVOO) could be retained in its byproducts during processing. Among them, hydroxytyrosol and its derivatives deserve special attention due to their health benefits recognized by The European Food Safety Authority (EFSA). In the present research, the presence of these compounds in the filter cake byproduct was studied by combining pressurized liquid extraction (PLE) and high-performance liquid chromatography coupled to time-of-flight mass spectrometry (HPLC-TOF-MS). The applied optimum extraction parameters were 1500 psi, 120 °C and aqueous ethanol (50:50, v/v). The influence of different drying methods (vacuum-, freeze- and spray-drying) in the recovery of phenolic compounds was also evaluated. A total of 16 compounds from EVOO were identified in the extracts, 3 of them being hydroxytyrosol-related compounds, 6 substances of oleoside and elenolic acid derivatives, together with 6 secoiridoids and 1 lignan. The results highlighted the great number of phenolic compounds recovered from filter cake with these techniques, being even higher than the reported content in EVOO and other byproducts. The combination of PLE and freeze-drying resulted in being the best procedure for the recovery of phenolic compounds from filter cake byproduct.