Investigation of Polyhenolic Content of Rose Hip (Rosa canina L.) Tea Extracts: A Comparative Study

Scarlet sage (Salvia coccinea) leaves were extracted with water, ethanol, methanol, and aqueous mixtures of those solvents by homogenizer-assisted extraction (HAE) and ultrasound-assisted extraction (UAE) methods, which are novel technologies used for this purpose. The best results were compared with those obtained by the conventional Soxhlet method (SM). Total phenolic content was expressed in gallic acid equivalent (GAE) per g of dried leaf. Free radical scavenging activity for the antioxidant capacity was tested by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical. The greatest amount of extraction was achieved by pure water with the value of 368.87 mg/g dried matter and the highest total phenolic content was observed by 100% methanol as 43.18 mg-GAE/g dried matter, both obtained by the HAE method. The mint leaves extracted by SM exhibited the highest antioxidant capacity, with a value of 90.55% for inhibition of DPPH radical.

Ultrasound-assisted extraction of polyphenols from rosehip (Rosa canina L.) was investigated. The aim of the study was to examine the extraction parameters such as extraction time (30-90 min), temperature (30-50 °C) and solvent concentration (40-100% ethanol, v/v), and to obtain the best possible combinations of these parameters by using response surface methodology. The experiments were performed according to the face-centred central design. Total phenolic content was expressed in gallic acid equivalent (GAE) per gram of dried matter (DM). The second-order polynomial model gave a satisfactory description of the experimental data. 47.23 mg GAE g(-1) DM was predicted at the optimum operating conditions (40% EtOH composition, 50 °C of temperature, and 81.23 min of extraction time). All of the parameters (ethanol concentration, extraction time and extraction temperature) used in this research have the significant effect on the extraction efficiency of total phenolic content in rosehip extracts (P < 0.05). The solvent concentration was proved to be the most significant effective on the yields obtained by ultrasound-assisted extraction.

Black rice (Oryza sativa L.) is a rich source of phenolics and anthocyanins. It was aimed to investigate the effect of different extraction methods such as conventional solvent extraction, ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE) on antioxidant activity and phenolic profiling of black rice free, esterified, and bound phenolics fractions. Spectrophotometric methods were used to evaluate antioxidant activity and HPTLC was used for phenolics profiling. The highest content of % yield, total anthocyanin (TAC), total phenolic (TPC), and total flavonoid (TFC) contents were detected in MAE. It was also observed that antioxidant activity based on DPPH, ABTS, superoxide radical-scavenging and ferric reducing antioxidant power (FRAP) assays showed highest activity in MAE. Eight phenolic compounds were identified and quantified by a validated HPTLC method. MAE showed most abundant phenolic compounds. A significant positive correlation was established between % yield, total phenolic content, and total flavonoid content (p<0.05) where a significant negative correlation was established between % yield, TPC, and TFC with IC50 of antioxidant activity (p<0.05). Diverse phenolic contents and antioxidant activity were studied with different forms of phenolics with the different extraction methods. It designates that the extraction techniques had effects on the bioactive compounds as well biological properties.

The potential for encountering free radicals poses a significant concern. Ketapang (Terminalia catappa L.) is a plant with antioxidant properties due to secondary metabolites, specifically phenolic compounds. The objective of this study was to determine the total phenolic content and antioxidant activity of ketapang leaves through the utilization of several extraction techniques. The extraction of Ketapang leaves is conducted using various methods, namely maceration, stirring-assisted extraction (SAE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE) with 1:10 solid-solvent ratio. The total phenolic content of the Ketapang leaf extract was determined using the Folin-Ciocalteu technique and quantified using a UV-Visible spectrophotometer set at a wavelength of 782nm. Meanwhile, antioxidant activity measurements were carried out using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and measured at a wavelength of 516nm. The study investigated the total phenolic content and antioxidant activity of Ketapang leaf extract using the maceration method of stirring-assisted extraction (SAE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), respectively, were 68.495%+2.891, 75.709%+0.106, 84.269%+0.159, and 65.065%+3.965 mgGAE/g and 20.891, 17.569, 15.427, and 21.353 µg/mL. The findings of this study indicate that the ultrasound-assisted extraction technique exhibits the greatest overall phenolic content and antioxidant activity. Keywords: antioxidant, Terminalia catappa, total phenolic content, ultrasound-assisted extraction

Senna didymobotrya has been used in Kenya by the Kipsigis community to control malaria as well as diarrhoea. The Pokot prepare charcoal from the stem for milk preservation. Research has not been done to investigate the effect of different extraction solvents on yield, total phenolic and flavonoid content of Senna didymobotrya plant roots. The aim of this study was to compare root extract yield of diethyl-ether, methanol, and aqueous solvents; phytochemical screening; and total phenolic and flavonoid content of Senna didymobotrya plant roots. Extraction was done by the Soxhlet method. Phytochemical screening was done using Harborne's (1973) method with a slight modification. Total flavonoid content was determined by aluminium chloride colourimetric assay at 420 nm. Total phenolic content was determined by Folin–Ciocalteu at 760 nm using UV-Vis spectrophotometry. Extraction yield of diethyl ether, methanol, and distilled water were 3.72 g (7.44%), 4.97 g (9.94%), and 9.09 g (18.18%), respectively, showing a significant difference (p &lt; 0.05) in the yields obtained using the different solvents. Phytochemical screening was positive for phenols, tannins, saponins, gladiac glycosides, anthraquinones, alkaloids, and flavonoids. Total flavonoid content was found to be 48.3 ± 1.5 (QEmg/g) and total phenol content was calculated as 34.5 ± 0.1 (GAEmg/g). Distilled water can be utilized as the best extraction solvent. Senna has a high amount of flavonoid and phenolic content. The limitation of this research is that it only tested root extracts and not leaves, flowers, or seeds. More studies need to be done to isolate the different compounds identified.

The aim of this study was to investigate the antioxidant and enzyme inhibition activities of methanol extracts prepared from Klasea serratuloides (DC) Greuter &amp;amp; Wagenitz subsp. karamanica B. Dogan &amp;amp; A. Duran with Soxhlet, ultrasonic extraction, and maceration methods. 1,1-Diphenyl-2-picryl hydroxyl (DPPH) quenching assay and 2,2’-azinobis-3- ethylbenzothiozoline-6-sulfonic acid (ABTS) cation decolorization test were used to evaluate in vitro radical scavenging activity. The total phenolic content was determined with the Folin-Ciocalteu method while the total flavonoid content was evaluated by the aluminum chloride colorimetric method. According to the results, DPPH, ABTS radical scavenging activity and iron chelating activity of methanol of Klasea serratuloides were shown concentration-dependent manner. The extract obtained from maceration was found to be higher than the other extracts. It suggests that the maceration technique was more effective than the other extraction methods for the determination of the phenolic content. The methanol extract of KS using soxhlet (61.17 ± 3.62) and ultrasonic extraction (58.76 ± 1.46) showed higher inhibition than the extract prepared with maceration methods (34.54 ± 0.73) against BChE. All extracts displayed moderate inhibition activity against AChE. As for enzyme inhibition activity, the extract from soxhlet method was found to be more potent tyrosinase, acetylcholinesterase and butyrylcholinesterase inhibitors than the other extracts prepared by ultrasound assisted extraction and maceration methods. The present study suggests that K. serratuloides should be given special attention to conduct further investigation for its phytochemical constituents that attribute to their antioxidant potentials, and enzyme inhibition activities.

Supercritical-CO2 extraction, Soxhlet extraction, and ultrasound-assisted extraction methods were conducted in this study to recover valuable components, specifically phenolic antioxidant compounds, from orange peels. Basic operating parameters such as temperature and pressure, which affect the extraction efficiency of phenolic substances in orange peel with supercritical-CO2, were designed using the central composite design methodology. In the Soxhlet and ultrasound-assisted extraction methods, 2-hour extraction processes were carried out using ethanol at different concentrations (50%, 80% and 100%) as a solvent. Yield comparison was made by performing total phenolic content, antioxidant activity and total flavonoid content analyses in the extracts. The total phenolic content (TPC) in the extracts was determined to be 5034 mg GAE/L for supercritical-CO2 extraction at 61.5°C and 20 MPa. In comparison, Soxhlet extraction yielded a TPC of 1728 mg GAE/L, while the ultrasound-assisted extraction method resulted in a TPC of 4056 mg GAE/L. It was determined that the optimum operating parameters of supercritical-CO2 extraction were 60°C and 26.4 MPa in case all the responses were maximized. The best phenolic recovery was obtained at 100% ethanol in Soxhlet extraction and 80% ethanol in ultrasound-assisted extraction. Although supercritical-CO2 extraction is an environmentally friendly application, the recovery rate of valuable components from raw materials is lower than in Soxhlet extraction and ultrasound-assisted extraction. However, since the volume of the extracts obtained from the supercritical-CO2 extraction is small, the ratio of phenolic compounds is higher.

Ultrasound-assisted extraction conditions optimisation using response surface methodology from Mitragyna speciosa (Korth.) Havil leaves

The hawthorn Crataegus mexicana is a traditional Mexican fruit with properties that make this fruit useful for the treatment of many ailments, including diseases of the respiratory and urinary tract. This paper reports the antioxidant capacity of the n-hexane, dichloromethane, ethyl acetate, acetone, ethanol and methanol extracts of C. mexicana. Samples were evaluated for total phenolic and carotenoid contents, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, the inhibition of the formation of thiobarbituric acid reactive species (TBARS) and the neutralization of the cation-radical 2,2´-azino-bis(3ethyl benzothiazoline-6-sulfonic acid) diammonium salt (ABTS). The total phenolic content was 2.65 ± 0.23 mg of gallic acid equivalents per gram, and the carotenoid content was 26.4 ± 0.02 µg/g in dry hawthorn skin. The most active extract in scavenging DPPH radicals and inhibiting TBARS formation was the acetone extract, with activities of 21.9 ± 0.15 and 13.27 ± 0.70%, respectively, at 10 mg/L. The extracts were compared for activity against ascorbic acid, caffeic acid, α- tocopherol and quercetin. The acetone extract was the most active, with an IC50 value of 15.2 mg/L in DPPH and 17.7 mg/L in TBARS. A high correlation was observed between the results for TBARS and DPPH. These results demonstrate the potential nutritional and antioxidant value of this Mexican fruit.

The medicinal plant Tribulus terrestris L. (TT) contains antioxidant and pharmacologically active phenolic compounds. However, extraction procedures can greatly affect extract yield, composition and biological activity. This study evaluated how conventional and advanced extraction methods affected TT extracts' phenolic content and antioxidant activity. TT was extracted using maceration, Soxhlet, ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) with ethanol-water solvent systems applied for different extraction times. The extracts were assessed for total phenolic content (TPC), total phenolic acid content (TPAC) and antioxidant capacity through 2,2-diphenyl-1-picrylhydrazyl (DPPH), cupric ion reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP) assays. Phenolic acid composition was analysed by HPLC. TPC values ranged between 27.66 and 37.98 mg GAE/g and TPAC between 8.273 and 24.337 mg CAE/g. Antioxidant activity (IC50) varied from 0.1132 to 0.1904 mg/mL, with UAE (80:20, 10 min) demonstrating the highest DPPH activity. CUPRAC and FRAP values extended from 97.462 to 308.769 mg TE/g and 8.917-17.291 mg TE/g, respectively, with UAE consistently yielding the most active extracts. HPLC detected eight phenolic acids, with protocatechuic acid (2.794 mg/g extract) being the most abundant, followed by p-coumaric, chlorogenic and caffeic acids. The extraction method affected the TT extracts' phenolic content and antioxidant capability. The UAE produced the highest phenolic-rich and bioactive extract. To maximise T. terrestris' phytochemical and nutraceutical potential, extraction procedures need to be optimised.

Comparison of microwave, ultrasound and ultrasound-microwave assisted solvent extraction methods on phenolic profile and antioxidant activity of extracts from jackfruit (Artocarpus heterophyllus Lam.) pulp

In this study, the betel leaf extracts were obtained by using an ultrasound-assisted extraction method with different solvents (70% ethanol, 96% ethanol, and water). The biological compounds of the extracts were examined using different biochemical assays, namely total phenolic content, total flavonoid content. ABTS+radical cation decolorization was using to determine the antioxidant activity. The antibacterial activity of the betel leaf extracts was determined using the agar diffusion and co-culture method. The obtained results of this study indicated that the betel leaf extract from the ethanol 96% was considerably more effective than other extracts in both antioxidant and antibacterial activity. The total phenolic and flavonoid content was 386.34 mg GAE/g extract and 55.07 mg QE/g extract, respectively. The half-maximal inhibitory concentration (IC50) of ABTS+ scavenging activity was 47.18 μg/ml. The betel leaf extract from the ethanol 96% showed more effectiveness in antibacterial than in antifungal. The minimum inhibitory concentrations of the 96% ethanol betel leaf extract on Candida albicans, Streptococus. mutans, S. pyogenes, Corynebacterium diphtheriae were 1000, 500, 500, 250 μg/ml, respectively. Results showed that the 96% ethanol ultrasound-assisted betel leaf extract has a potential application in pharmaceuticals and cosmetics.

Stevia leaves, which are commonly used as a natural sweetener in food products, have increased in importance for antioxidant delivery due to their high content of phenolic compounds. In this study, the influence of the drying process on stevia leaves, with regards to phenolic content and antioxidant activity during drying kinetics 40 °C for 7 h, was studied. The effect of solvent concentration and extraction time using a 32 factorial design on total phenol content (TPC), and on antioxidant activity of extracts obtained from dried stevia leaves, by ultrasound assisted extraction (UAE) as alternative method was evaluated. Steviol glycosides contents were also evaluated by a conventional and UAE method. Phenols identification, quantification and purification were performed by Ultra Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (UPLC-ESI-MS), Ultra Performance Liquid Chromatography-Photodiode Array (UPLC-PDA) and advanced automated flash purification, respectively. Drying time affected the moisture content of stevia leaves. A constant weight was reached after six hours of drying, and higher antioxidant activity was observed, while the highest TPC was obtained after seven hours of drying. The highest TPC (91.57 ± 8.8 mg GAE/g dw) and antioxidant activity (603.24 ± 3.5 μmol TE/g dw) in UAE method was obtained when ethanol 50% at 5 min was used. Steviol glycosides extracted by UAE were recorded with a content of 93.18 ± 1.36 mg/g dw and 98.97 ± 1.75 mg/g dw for stevioside and rebaudioside A respectively. Six phenolic compounds including four phenolic acids and two flavonoids were identified and quantified by UPLC-PDA, and confirmed by ESI-MS reporting its fragmentation pattern. Diosmin and chlorogenic acid were the most abundant compounds with values of 2032.36 μg/mL and 434.95 μg/mL respectively. As a novelty we found that the antioxidant activity evaluated in partially purified fractions suggested that biological activity might be attributed to the synergistic effect of the six phenols present in the stevia leaves extract. In addition to its sweeting properties, stevia leaves constitute a potential source of polyphenolic compounds, with antioxidant activity that could be used as a food additive.

Aim: The current study was undertaken to determine the total phenolic and flavonoid contents and to assess the antioxidant activity of two different extracts (flour and oil) of two Algerian Quercus species, Quercus ilex L. and Quercus suber L. Methods and Material: The oil extraction of the two species was achieved using the Soxhlet method. The obtained extracts were estimated for the chemical and physical constants (acidity, peroxide value, iodine value, and ultraviolet absorption indices). Total phenolic content was measured by spectrophotometry according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). The studied extracts were submitted to an estimation of their flavonoid contents too, using aluminum chloride methods. Antioxidant ability was assessed by means of two distinct methods (DPPH• and ABTS•+). Results: The obtained results revealed that antioxidant properties, total phenolic, and total flavonoid contents differed significantly among selected species and extracts. The flour samples possessed the highest level of total phenolic contents (1101–1464 mg GAE/kg dry weight) and exhibited the highest antioxidant capacities with average values of 52.62–40.78 μmol TE g−1 dry weight and 36.19–44.50 μmol TE g−1 dry weight for DPPH and ABTS assays, respectively. Acorn oil extracts showed also remarkable antioxidant activity, up to 2.69 and 3.23 μmol TE g−1 oil (DPPH and ABTS test, respectively), even though the total phenolic contents were low (195.64–322.06 mg GAE /kg of oil). Total phenolic amounts were positively correlated with the antioxidant properties of Quercus flour and oil. Conclusions: Our study provides basic information on the presence of bioactive compounds and antioxidant capacity in acorn fruits, in order to consider their extracts as functional food ingredients and potential source of natural antioxidants. Keywords: Quercus ilex L., Quercus suber L., Total phenolic, Total flavonoid, Antioxidant activity.

Hedyotis corymbosa L. (H. corymbosa) is an Indonesian herbal plant with many health benefits. This activity comes from secondary metabolite compounds, one of which is flavonoids. These compounds can be obtained through an extraction process, where the extraction method is one of the factors that can affect the levels of compounds. This study aims to determine the effect of conventional extraction methods: maceration and soxhletation with non-conventional methods, Ultrasound Assisted Extraction (UAE) on the total flavonoid content of H. corymbose. The sample was extracted using 70% ethanol solvent (1:10 w/v) with the maceration, soxhletation, and UAE methods. The total flavonoid content of the H. corymbosa extract was measured using UV-Vis spectrophotometry. The data obtained were then analyzed statistically using SPSS One-Way ANOVA, followed by Post Hoc Tukey with a 95% confidence level. The soxhletation method has the highest flavonoid content at 72.255±1.334 mg QE/g, followed by UAE at 69.118±1.782 mg QE/g, and maceration at 43.725±0.679 mg QE/g. Statistical analysis confirmed that the extraction method significantly influences total flavonoid content. While both soxhletation and UAE methods produced similarly high flavonoid contents, UAE offers a substantial advantage in efficiency due to its shorter extraction time, making it a promising alternative to conventional soxhletation.