Total Flavonoid Compounds Research Articles

Solvent effect on phenolics and antioxidant activity of Huangshan Gongju (Dendranthema morifolium (Ramat) Tzvel. cv. Gongju) extract

Huangshan Gongju was extracted with organic solvents (ethanol, methanol and acetone) of different concentrations (0–90%), and the extracts’ phenolic content and antioxidant activity, as well as the correlations between them were examined. With the increasing concentration of organic solvent, the total phenolic compound (TPC) increased continuously and met its maximum at 70% acetone, whereas the total flavonoid compound (TFC) and most individual phenolics met their maximums at 70% ethanol. Similar changes occurred to the antioxidant activity, including DPPH and ABTS scavenging activities, and their maximums were respectively found at 50% acetone and 70% ethanol. The antioxidant activity correlated strongly with TPC/TFC (r > 0.954, p < 0.01) and individual phenolics (r > 0.886, p < 0.05), and the strongest correlations between them were mainly given by luteolin-7-O-glucoside (r > 0.975, p < 0.001). These results suggested that high content organic solvent (50–70%) was beneficial to obtain Huangshan Gongju extracts of higher phenolic content and antioxidant activity, and 70% ethanol may be the promising solvent. Besides, phenolics were found to be the main antioxidants of Huangshan Gongju extracts, and flavonoids especially luteolin-7-O-glucoside may play more important roles in the antioxidant activity.

Preliminary Study of Microelements, Phenolics as well as Antioxidant Activity in Local, Homemade Wines from North-East Greece.

The present study is aimed to analyze the composition of microelements in wines prepared by amateur winemakers in Drama region (recognized as Protected Geographical Indication (PGI)), especially the toxic ones, as well as the phenolic content and antioxidant activity of these wines since moderate wine consumption may contribute to health benefits to the consumers. A total of twenty-four wines, comprising sixteen red and eight white, were tested. The micro and macroelements were determined with ICP-OES (Inductively coupled plasma-optical emission spectrometry). Chromatic characteristics of wines and total phenolic and flavonoid compounds as well as their antioxidant activity with three different assays were determined spectrophotometrically. The amateur’s wines showed levels of contaminants with toxic metals less than the limits set from the International Organization of Vine and Wine (OIV). Moreover, toxic metals concentrations were comparable to those of European wines. The Principal Component Analysis discriminated wines into white and red and further distinguished the red wine into two groups depending on the Total Flavonoid content, antioxidant activity and color intensity. The moderate consumption of amateur wines can be recommended since their consumption is not harmful to the health, and they contain high amount of phenolics and flavonoids comparable or even higher to that of commercial wines.

Lantana trifolia: Phytochemical and elemental composition, proximate contents and gas chromatography–mass spectrometry profile

Background: With increasing concern over food insecurity, there is the need to incorporate wild edible plants in our meals as they can provide adequate level of nutrition when consumed as food. Aim: The objective of this study was to evaluate the proximate composition, elemental composition, total phenolic content, total flavonoid content and gas chromatography–mass spectrometry (GC-MS) profile of Lantana trifolia . Setting: This study was carried out in Juja, Kenya where the samples were collected, prepared and stored at the Department of Chemistry, Jomo Kenyatta University of Agriculture and Technology. Methods: The proximate and elemental compositions of the leaves, stalk and root samples were evaluated by using standard procedures, whilst the total phenolic and flavonoid contents were evaluated by using Folin–Ciocalteu and aluminium chloride method. The secondary metabolites present in the crude methanolic extracts of the whole plant were determined by using GC-MS. Results: The proximate and elemental analyses of the plant revealed that L. trifolia can be a good source of essential elements, proteins, crude fibre and carbohydrates. The protein, fat, crude fibre and carbohydrate contents in the leaves were found to be higher compared with the stalks and roots, whilst the ash and moisture contents were found to be higher in the roots. The concentrations of calcium, iron, magnesium and zinc in the leaves were found to be 8860.75 ± 565.27, 11 003.10 ± 143.24, 1520.25 ± 26.85 and 39.66 ± 15.68 mg/kg, respectively, compared with the roots and stalks, which were lower. Conclusion: The concentration of total phenolic and total flavonoid compounds and GC-MS profile of the methanolic extracts revealed that L. trifolia can be a good source of secondary metabolites, some of which have reported to be free radical scavengers. Hence, L. trifolia can not only be used as a source of important secondary metabolites, but its nutritional content suggests that the plant can be used to combat nutrient deficiency amongst many communities who lack adequate resources, because it thrives in the wild.

In vitro and In silico Analysis of Pomegranate (Punica granatum L.) Fruit Powder as Pancreatic Lipase and α-Amylase Inhibitor

This study aims are to produce pomegranate powder, then to extracted with boiling water and to find out the phytochemical compounds, total phenolic compounds (TPC), total flavonoid compounds (TFC) and its inhibitory activity against pancreatic lipase by in vitro analysed. Besides of that, a compound that exist in pomegranate will also be in silico analysed by docking technique, for its binding with the α-amylase enzyme compared to acarbose. In vitro inhibition tests were conducted by titrimetric method, using olive oil as substrate, pancreatic lipase as enzymes, and orlistat as a standard inhibitor; meanwhile the in silico test was conducted by molecular docking techniques using human α -amylase as a receptor and acarbose and a compound in pomegranate (quercetin) as ligand. The result has shown that hot water extracts of pomegranate fruits powder (1.5 gr/150 ml) contained flavonoids, polyphenols, and alkaloids and TPC and TFC contents were 2.090 ppm and 2.058 ppm, respectively; had pancreatic lipase inhibition activity of 0.54 times compared to orlistat at the same mass (120 mg), and based on its molecular docking, quercetin, a compound in the pomegranate can bind to the α-amylase enzyme in a position that is relatively the same as acarbose, even with slightly larger affinity bindings.

Dendropanax morbifera Leaf Extracts Improved Alcohol Liver Injury in Association with Changes in the Gut Microbiota of Rats.

This study evaluated the protective effects of Dendropanax morbifera leaf (DML) extracts in the liver due to excessive ethanol consumption. Our results showed that the ethanol extract had better antioxidant activity than the water extract, likely due to the higher levels of total flavonoid and phenolic compounds in the former. We found that the main phenolic acid was chlorogenic acid and the major flavonoid was rutin. Results from the animal model experiment showed concentration-dependent liver protection with the distilled water extract showing better liver protection than the ethanol extract. Gut microbiota dysbiosis induced by alcohol consumption was significantly shifted by DML extracts through increasing mainly Bacteroides and Allobaculum. Moreover, predicted metabolic activities of biosynthesis of beneficial monounsaturated fatty acids such as oleate and palmitoleate were enhanced. Our results suggest that these hepatoprotective effects are likely due to the increased activities of antioxidant enzymes and partially promoted by intestinal microbiota shifts.

Primitive techno-economic study of bio-diesel and bio-active compound production from microalgae

BackgroundMicroalgae cells can be identified as a potential source for new and renewable energy. The economic investigation for biodiesel and bio-active compound production from the microalgae community (Bloom), which are collected from the high rate algal pond (HRAP) constructed to treat municipal wastewater at Zenin wastewater treatment plant, Giza, was the main target of study.ResultsThe microscopical examination showed that Scenedesmus obliquus is the dominant species. The total carotenoids were extracted using jojoba oil and determined by high-performance liquid chromatography (HPLC) to reach 81.44 μg/g. The biodiesel production through acid transesterification reaction recorded 70.6% of fatty acid methyl ester content with high cetane number (44) and low acid value. Such results prove that the obtained biodiesel has better ignition quality. The total phenolic and flavonoid compounds have been derived from the remaining biomass to give 5.36 ± 0.03 and 1.50 ± 0.19 mg/g respectively. Finally, total proteins and carbohydrates content in algal cells were recorded 54.3 and 1.5 mg/g successivelyConclusionThe preliminary economic evaluation showed that the production of biodiesel and carotenoids from the microalgae growing in municipal wastewater can be considered, as a techno-economic feasible process.

Study on optimization of ultrasonic assisted extraction of phenolic compounds from rye bran

Ultrasonic assisted extraction (UAE) conditions for the extraction of phenolic compounds from rye bran (RB) were optimized by using response surface methodology. The optimal conditions for UAE were; time: 29 min, temperature: 66 °C, and solid to solvent ratio: 1:45 (g/mL), which provided a total phenolic content of 245.74 mg GAE/100 g dw. Compared with conventional extraction (CE) technique, UAE resulted in higher yield of total phenolic and flavonoid compounds, whereas only a slight difference was reported in the total flavonol and proanthocyanidin content. The UAE extract showed higher antioxidant activity in all antioxidant assays (DPPH, FRAP, ABTS, reducing power, and H2O2). The phenolic composition of both extracts was analyzed using HPLC-MS. Resultantly, a significant (p < 0.05) increase in the concentration of phenolic acid was observed when the extraction was accomplished with UAE as compared to CE. Both UAE and CE extracts exhibited in vitro hypoglycemic activities by inhibiting α-amylase and α-glucosidase enzymes. However, no significant differences (p > 0.05) were observed in the FTIR spectra of UAE and CE treated RB. These finding indicates that UAE increased the yield of phenolic compounds from RB. Furthermore, these phenolic compounds could be used as a potential source of natural antioxidants.

Instant Controlled Pressure Drop as Blanching and Texturing Pre-Treatment to Preserve the Antioxidant Compounds of Red Dried Beetroot (Beta vulgaris L.).

Red beetroot is rich in bioactive compounds such as polyphenols, flavonoids, betaxanthins, betacyanins, among others. According to selected processing methods, the bioaccessibility of these compounds could be either enhanced or decreased. This study evaluated the effect of four different drying conditions: (1) Traditional Drying (TD), (2) Swell Drying (SD), (3) DIC Blanching + Traditional Drying (BTD), and (4) DIC Blanching + Swell Drying (BSD) on the antioxidant content and the antioxidant activity of red beetroots. Obtained results showed that in all the cases, by comparing to Traditional Drying (TD), the coupling of a DIC Blanching pre-treatment to a Swell Drying treatment (BSD) maintained or enhanced the preservation of the Total Phenolic Compounds (TPC), the Total Flavonoids Compounds (TFC), the Betanin Concentration (BC), the Trolox Equivalent Antioxidant Capacity (TEAC), and the Free Radical Scavenging Activity by DPPH (IC50) of red beetroots. Various studies have shown that thanks to the expanded and porous structure triggered by the Swell Drying process, it has been possible to achieve better antioxidants extraction and better whole quality. Hence, by coupling DIC as a blanching–steaming pre-treatment, it was possible to preserve better the antioxidant content and the antioxidant activity of red dried beetroots.

Characteristic of yellow tuna skin (Thunnus albacares) gelatin enriched with cinnamon (Cinnamomum zeylanicum) and roselle (Hibiscus sabdariffa) powder

The current practice condition of fish processing will generate some amounts of byproducts such as skin waste. These fish processing by-products can be considered as an alternative raw material for the preparation of high protein ingredients such as gelatin. Gelatin extraction from the skin of yellowfin tuna (Thunnus albacares) was conducted by the acid process. Afterwards, the fish gelatin was mixed with cinnamon (GECP) and roselle powder (GERP) to enhance the physicochemical and functional properties of gelatin. The effects of the addition of cinnamon (GECP) and roselle powder (GERP) on the physicochemical and the functional properties such as tensile strength, hardness, viscosity, water holding capacity, oil holding capacity, total flavonoid, total phenolic, total antioxidant and flavor compounds of enriched gelatin (GECP and GERP) from tuna skin were evaluated and compared with control (without the addition of cinnamon and roselle powder). The gelatin exhibited excellent tensile strength, WHC, OHC, total flavonoid, total phenolic, and antioxidant in the presence of cinnamon and roselle powder rather than control (without addition) (p&lt;0.05). The flavor analysis by using GC-MS showed more cinnamaldehyde as one important flavor compounds in GECP and where cyclohexanones can be identified as one important flavor compound in GERP. Thus, this study confirmed the improvement of physicochemical properties of gelatin enriched with cinnamon and roselle powder.

Effect of Extraction Conditions on The Phytochemical Properties of Clinacanthus nutans Using Pressurized Hot Water Extraction (PHWE) Technique

Clinacanthus nutan is an important herb species from the family Acanthaceae and is commonly found in Southeast Asia. It is also known as snake grass, or ‘belalai gajah’ in malay. The leaves of C. nutan can be used to make a refreshing juice or tea, or even consumed raw as ‘ulam’, a traditional malay salad. In this work, the leaves, stems, and a mixture of both leaves and stems of C. nutan are first dried in an oven at 50°C for 24 hours and then grounded into a powder. Then, pressurized hot water extraction (PHWE) is used to extract phytochemicals from the powdered samples at 120°C for 20 minutes. This work investigates the effects of three important parameters for extraction; the sample particle size (<63 to 500μm), solventto-sample ratio (10:2 to 50:2 v/w), and sample weight (0.5 to 3.0g) on the extracted phytochemicals’ total phenolic compounds (TPC), total flavonoid compounds (TFC), and 2,2-dipheny1-1picrylhydrazyl (DPPH) scavenging activity. The experiments are carried out in triplicate and the results are analyzed using Minitab. Phytochemicals extracted from 2g leaf powder samples of particle size <63μm using a solvent-tosample ratio of 50:2 (v/w) resulted in the most favorable results for TPC, TFC, and DPPH scavenging activity. The results are found to be significant with the

Antioxidants and Antibacterial Activities of Bioactive Compounds of Clove (Syzygium aromaticum) and Thyme (Tymus vulgaris) Extracts.

Recently, there is an increasing attention in finding antioxidant phytochemicals natural to avoid the effects of synthetic antioxidants and antimicrobialcompounds. In this study, two herbs namely clove buds (Syzygium aromaticum) and thyme leaves (Tymus vulgaris), were used to extract the bioactive compounds. The chemical composition of clove buds and thyme leaves was determined. Ethanolic and aqueous extractions were carried out to obtain biological active compounds. Ethanolic clove-powdered buds extracts had the highest total phenolic compounds (TPC) (372.21 mg GAE/g extract) while, essential oil extract of thyme-powdered leaves was (158.83 mg GAE/g extract). Total flavonoids compounds (TFC) of ethanolic clove-powdered buds extract was (177.15 mg QE/g extract) but aqueous extract of thyme-whole leaves was (126.50 mg QE/g extract). The reducing power of thyme-powdered leaves was (1.022) comparable with vitamin C (8.911) meanwhile, clove- powdered buds extract was (1.031). Free radical scavenging capacity of clove-whole buds was (IC 50 ; 2.75 µg/mL) and thyme-whole leaves extracts had (IC 50 ; 2.86 µg/mL) comparable with ascorbic acid (IC 50 ; 6.75 µg/mL). The antibacterial of all used herbs extracts against Escherichia coli, bacillus cereus and Staphylococcus aureus. Were studied. On Escherichia coli, thyme-powdered leaves essential oil had (19.75mm inhibition zone) while, clove-whole buds ethanolic extract was (14.5 mm inhibition zone). Thyme-whole leaves essential oil was (24.5 mm inhibition zone) against Staphylococcus aureus, but clove-whole buds essential oil extract was (12.25 mm inhibition zone). Aqueous extract obtained from thyme-powdered leaves was (14.5mm inhibition zone) While, clove-powdered buds ethanolic extract was (13.5 mm inhibition zone) against bacillus cereus.

Antioxidant and Cytoprotective Properties of Cyanobacteria: Potential for Biotechnological Applications.

Antioxidant compounds from cyanobacteria may constitute a natural alternative to current synthetic antioxidants, which contain preservatives and suspected toxicity. In this work, we evaluate the antioxidant potential of cyanobacterial strains of distinct species/genus isolated from freshwater (n = 6), soil (n = 1) and wastewater (n = 1) environments. Lyophilized biomass obtained from in-vitro cultures of those strains was extracted with ethanol and methanol. The antioxidant potential was evaluated by chemical (DPPH scavenging method, β-carotene bleaching assay, determination of total phenolic and total flavonoid compounds) and biological (H2O2-exposed HEK293T cell line model) approach. Some strains showed high yields of antioxidant activity by the DPPH assay (up to 10.7% IP/20.7 TE μg/mL) and by the β-carotene bleaching assay (up to 828.94 AAC), as well as significant content in phenolic (123.16 mg EAG/g DW) and flavonoid (900.60 mg EQR/g DW) compounds. Normalization of data in a “per cell” or “per cell volume” base might facilitate the comparison between strains. Additionally, most of the cyanobacterial extracts conferred some degree of protection to HEK293T cells against the H2O2-induced cytotoxicity. Freshwater Aphanizomenon gracile (LMECYA 009) and Aphanizomenon flos-aquae (LMECYA 088), terrestrial Nostoc (LMECYA 291) and wastewater Planktothrix mougeotii (LEGE 06224) seem to be promising strains for further investigation on cyanobacteria antioxidant potential.

Extracts from strawberry by-products rich in phenolic compounds reduce the activity of apple polyphenol oxidase

The ultrasound-assisted extraction of phenolic compounds from strawberry by-products was studied varying the solvent type (water, ethanol 80%, methanol 80%, and acetone 80%), the formic acid concentration (0 and 0.5%), and the number of extraction steps (1 and 2). Total phenolic and total flavonoid compounds were determined spectrophotometrically and analyzed by PAD-HPLC. The antioxidant capacity (DPPH and FRAP assays) and the ability of extracts to inhibit apple (Malus domestica cv. ‘Red Delicious’) polyphenol oxidase (PPO) were also investigated. Extracts with acidified methanol in two-steps yielded the highest phenolic compound concentration (15.01 g/kg), and the highest antioxidant capacity. Agrimoniin was the major polyphenol found, and the extraction with acetone in two-steps produced the highest yield (2.45 g/kg). This ellagitannin was the only polyphenol that correlated (R2 > 0.80, p < 0.05) with the antioxidant capacity. Water and ethanol showed the lowest phenolic compound yields. However, extraction with these green solvents (water or ethanol) in two-steps showed polyphenol contents similar to those obtained with methanol or acetone in one-step (≈9 g/kg). Additionally, extracted polyphenols (0.24 g/L) produced 30% apple PPO inhibition, in a reversible ‘uncompetitive’ inhibition. Results showed the high revalorization potential of strawberry by-products as a low-cost source of polyphenols, with antioxidant and anti-browning effects.

Synergic Involvements of Microorganisms in the Biomedical Increase of Polyphenols and Flavonoids during the Fermentation of Ginger Juice

Steered fermentation by microorganisms gives great added value in the nutritional quality of local food. Ginger rhizome naturally contains a myriad of bioactive compounds including polyphenol and flavonoids. The aim of this work was to ferment the ginger juice, to evaluate the biochemical parameters of ginger wine, and to understand the involvement of microorganisms in the bioincrease of polyphenol compounds. Titratable acidity and pH values were determined and showed that pH is around 1.6 at the end of the fermentation when the acidity is around 6.431 g/L. Using colorimetric assay, the total polyphenolic and flavonoid compounds were evaluated throughout the fermentation. The variation of the polyphenol and flavonoid concentrations of the unsweetened sample was around 10.18 to 14.64 mg Eq AG/g and 1.394 to 2.224 mg Eq Cat/g Ms, but those from the sweet sample were around 10.82 to 18.34 mg Eq AG/g Ms and 1.311 to 2.290 mg Eq Cat/g. Using one-step PCR, multiplex techniques with specific primers, with yeast-like phenotype 27.27% (6), have been assigned among 22 isolates to Saccharomyces cerevisiae. By using PCR multiplex techniques, Bacillus licheniformis, Bacillus pumilus, Bacillus safensis, and Saccharomyces cerevisiae have been identified. Together with Saccharomyces cerevisiae, we showed that Bacillus sp. are able to secrete enzymatic landscape with some activities up to 50% including cellulase, amylase, pectinase, and protease.

Melaleuca leucadendron (L.) L. flower extract exhibits antioxidant and photoprotective activities in human keratinocytes exposed to ultraviolet B radiation

Recently, there has been a demand for the replacement of chemical sunscreens with natural compounds that could prevent or restore UV-induced skin damage. Here, we investigated the photoprotective influence of the Melaleuca leucadendron ethanolic flower extract (EEMec) on factors involved in cellular and molecular UVB-induced oxidative stress in human skin keratinocytes (HaCaT). The phytochemical constituents, antioxidant potential by DPPH assay, content of total phenolic and flavonoid compounds in EEMec were evaluated. HaCaT cells were treated with EEMec followed by irradiation with UVB. CAT activity; GSH and ROS levels; and SOD1, GPx, CAT and COX-2 expression assays were employed to verify the oxidative stress, as well as EEMec effect on transmembrane transport, and pro-inflammatory and pro-apoptotic protein expression. EEMec reverted the viability loss of HaCaT cells after irradiation with UVB, exhibited significant antioxidant capacity and free radical scavenging activity in vitro, inhibited COX-2 expression and ensure protection of DNA-damage. EEMec shown a great photoprotective property to prevent keratinocytes damage induced by UV radiation and, thus a candidate potential to application as an adjuvant in sunscreen formulations as a strategy to reduce risk of sunburn and prevent skin diseases associated with UV-induced inflammation and cancer.

Phytochemical screening and determination of phenolics and flavonoids in Dillenia pentagyna using UV-vis and FTIR spectroscopy.

Here, we report an ultrasonic-assisted extraction (UAE) of phytochemicals from bark, leaves, sepals, fruits, and seeds of Dillenia pentagyna (Roxb) using different organic solvents such as chloroform, ethanol, and n-hexane. The preliminary phytochemical screening results showed that the ethanolic extract is enriched with phenolics, flavonoids, tannin, saponin, alkaloid, and terpenoids. The profiling of phytochemicals is carried out employing UV-Vis and Fourier-transform infrared (FTIR) spectroscopy analyses. The higher amount of phenolic compounds obtained in the ethanolic extract of bark and leaves as compared to other parts of the plant. Consequently, a higher amount of total flavonoid compounds unveiled in the bark of targeted species. The ethanolic extract of bark and leaves showed good free radical scavenging activity using DPPH with inhibition percentage of 90.58±1.89% and 76.46±1.58%, respectively, in comparison to standard ascorbic acid at 10μg/mL. Moreover, the half-maximal inhibitory concentration (IC50) value of bark and leaves are 5.64 and 6.54μg/mL, respectively, in comparison to standard ascorbic acid. With the best of our knowledge, it is the first report pertaining to characterization and quantification of phenols and flavonoids as well as the investigation of the medicinal property in D. pentagyna.

Reuse of Hot Trub as an Active Ingredient with Antioxidant and Antimicrobial Potential

The reuse of agro-industrial residues is vital to minimize their environmental impact and alternatives for their application are needed. In this research, we evaluated the chemical composition as well as antioxidant and antibacterial activities of the extract from hot trub, that is the second solid waste obtained during the brewing process. Total phenolic and flavonoids compounds were determined by colorimetric assays and the compounds were identified by UHPLC-DAD-MS/MS. Antioxidant activity was evaluated by ABTS and DPPH methods. Antibacterial activity against Gram-positive and Gram-negative bacteria was analyzed by agar diffusion and microdilution methods. Cytotoxicity was evaluated against murine fibroblast L929 cell line by MTT assay. The results showed that the content of phenolic and flavonoid compounds ranged according to the fractions from 8.237 to 13.390 mg GAE/g and from 0.019 to 1.643 mg QE/g, respectively. The compounds cohumulone, cohulupone, hulupone/adhulupone, isoxanthohumol, xanthohumol, hydroxytricyclocolupone epimers, hydroxytricyclolupone/hydroxytricicloadlupone epimers and nortricyclocolupone were suggested. Higher antioxidant activity was observed for the crude ethanol extract. The hexane fraction presented the lowest MIC value against Gram-positive bacteria, as well as lower cytotoxicity. These results are promising and indicate a great potential for the reuse of this byproduct as a source of natural antioxidant and for the microbiological applications, which consequently would reduce the environmental impact.

Hydrodynamic performance of 3D printed turbulence promoters in cross-flow ultrafiltrations of Psidium myrtoides extract

Membrane separations for fruit juice processing have been largely investigated, but membrane fouling is still a limitation to be overcome. Here, the use of turbulence promoters to increase the permeate flux of purple araça fruit (Psidium myrtoides) extract through flat polymeric membranes was investigated. The turbulence promoters were produced using 3D printing technology with two different cylindrical pin diameters (2.5 and 3.5 cm). Results show that the ultrafiltration membrane was efficient to concentrate the bioactive compounds of purple araça fruit extract. Retentions of total polyphenol and flavonoid compounds were 95 % and 90 %, respectively. The use of turbulence promoters increased the permeate flux by up to 78 %. According to computational fluid dynamics (CFD), the turbulence promoters with diameters of 2.5 and 3.5 mm increased the flow velocity on the membrane surface in 38.4 % and 30.7 %, respectively, and increases in turbulence intensity were of 69.0 % and 43.2 %, respectively. In addition, the turbulence promoters with diameters of 2.5 and 3.5 mm increased the wall shear stress from 1.57 to 3.12 and 3.07 Pa, respectively. Thus, the turbulence promoters had positive effects on hydrodynamics during ultrafiltration of purple araça fruit extract.

Two endemic Onosma species (O. sieheana and O. stenoloba): A comparative study including docking data on biological activity and phenolic composition

There are convincing evidences that species belonging to the Onosma genus have been used in the treatment of various diseases for centuries. In this study, antioxidant and tyrosinase and α-amylase inhibitory activities of the methanol (MeOH) extracts of two endemic Onosma species (O. sieheana Hayek and O. stenoloba Hausskn. ex Riedl), which are endemic to the flora of Turkey, were compared. Phosphomolybdenum, reducing power [Cupric reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP)], radical scavenging [on '2,2-diphenyl-1-picrylhydrazyl' (DPPH) and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS)] and ferrous ion chelating assays were used to determine the antioxidant activities of the extracts. All test systems except for the ferrous ion chelating assay resulted in O. sieheana's superiority. The antioxidant activity of O. sieheana in the test systems mentioned above was found to be 2.11, 1.57, 1.01, 3.54 and 3.19 mg/mL, respectively. However, in ferrous ion chelating activity assay, O. stenoloba showed higher activity with an IC50 value of 2.98 mg/mL. In the tyrosinase inhibitor activity test, O. stenoloba extract showed higher activity (1.89 mg/mL), while in the α-amylase inhibitory activity assay, O. sieheana was found to be more effective (3.02 mg/mL). As a result of total phenolic and flavonoid compound analysis, O. sieheana was found to be richer than the other in terms of both groups. LC–ESI–MS/MS analysis revealed that rosmarinic acid, apigenin 7-glucoside, luteolin 7-glucoside, chlorogenic acid, hesperidin, pinoresinol, hyperoside and 4-hydroxybenzoic are the main compounds of the extracts. According to the results of docking analysis performed to reveal the interactions of the main components with tyrosinase, it is thought that pinoresinol, hesperidin, luteolin 7-glucoside, apigenin 7-glucoside, and hyperoside may be phytochemicals responsible for the inhibitory activity. Additionally, the binding energies of pinorecinol, apigenin 7-glucoside, luteolin 7-glucoside, hyperoside, chlorogenic acid, and rosmarinic acid to α-amylase were found to be quite high.

In Vitro Antioxidant Property and Phytochemical Constituents of Senna alata Leaves Aqueous Extract Collected in Ngaoundéré (Cameroon)

Leaves extract of Senna alata L. is a plant used as indigenous medicine to treat various types of disease like ulcers, stomach, pain and fever. The present study was undertaken to study the phytochemical screening, total phenolic compounds (TPC), total flavonoid compounds (TFC) and in vitro antioxidant of Senna alata leaves’ extract growing in Ngaoundéré town (Cameroon). Respective bioactivities of the phytochemicals were determined. Quantitative analysis of the total phenolic content was determined by using the Folin-Ciocalteu method while total flavonoid was estimated using aluminium trichloride (AlCl3). The antioxidant capacities in the forms of DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (Ferric Reducing Antioxidant Power) were evaluated by spectrophotometric methods. For these purposes, aqueous extract were prepared. Now the experimental screening of phytochemicals showed negative results for the absence of reducing compounds, steroids/triterpenes, and tannins. The results showed that TPC, TFC values were higher: 14.768±0.26 mg GAE per g of extract, 4.32±0.12 mg Ru per g of extract, respectively. The Senna alata Leaves’ extract (SALE) exhibited the best DPPH inhibition concentration 50% (IC50 = 12.05 mg. mL-1), and FRAP method (IC50 = 2.79 mg. mL-1) compared to that of the positive control, ascorbic acid (IC50 = 17.69 mg/mL); Hence, extract from the leaves of Senna alata contains high secondary metabolites which accounts for its strong antioxidant ability thus justifying its use as natural occurring antioxidants in folkloric medicine.