Secondary Metabolites from the Fresh Leaves of Pinus yunnanensis Franch.

Fifteen metabolites, including two flavonols (1-2), three lignans (3-5), and ten diterpenoids (6-15), were isolated from the leaves of Pinus yunnanensis. Among them, flavanonol (1) were identified as undescribed flavonol derivative with natural rarely B-ring fission lactone. Massive spectroscopic methods, the DP4+ probabilities and CD/ECD calculations were applied to establish the structure of component 1. Among these compounds, taxifolin (2) showed potent cytotoxicity, having IC50 values from 21.33 to 45.48 µg/mL, it also showed broad antibacterial activity against human pathogens with MIC values from 32 to 64 µg/mL.

High-Resolution UPLC-MS Profiling of Anthocyanins and Flavonols of Red Cabbage (Brassica oleracea L. var. capitata f. rubra DC.) Cultivated in Egypt and Evaluation of Their Biological Activity.

In this paper, biological investigations and a high-resolution UPLC-PDA-ESI-qTOF-HRMS technique were employed for Brassica oleracea L. var. capitata f. rubra DC. (red cabbage) of the family Brassicaceae (Cruciferae), cultivated in Egypt, for the first time. The positive ionization mode is usually performed to identify anthocyanins. However, this technique cannot differentiate between anthocyanins and corresponding non-anthocyanin polyphenols. Thus, the negative ionization mode was also used, as it provided a series of characteristic ions for the MS analysis of anthocyanins. This helped in identifying five kaempferol derivatives for the first time in red cabbage, as well as nine-previously reported-anthocyanins. For the biological investigations, the acidified methanolic extract of fresh leaves and the methanolic extract of air-dried powdered leaves were examined for their antioxidant, antimicrobial, and anticancer activities. The freshly prepared phenolic extract was proven to be more biologically potent. Statistical significance was determined for its anticancer activity in comparison with standard doxorubicin.

Isolation of N-Ethyl-2-pyrrolidinone-Substituted Flavanols from White Tea Using Centrifugal Countercurrent Chromatography Off-Line ESI-MS Profiling and Semi-Preparative Liquid Chromatography.

N-Ethyl-2-pyrrolidinone-substituted flavanols (EPSF) are marker compounds for long-term stored white teas. However, due to their low contents and diasteromeric configuration, EPSF compounds are challenging to isolate. In this study, two representative epimeric EPSF compounds, 5'''R- and 5'''S-epigallocatechin gallate-8-C N-ethyl-2-pyrrolidinone (R-EGCG-cThea and S-EGCG-cThea), were isolated from white tea using centrifugal partition chromatography (CPC). Two different biphasic solvent systems composed of 1. N-hexane-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v) and 2. N-hexane-ethyl acetate-acetonitrile-water (0.7:3.0:1.3:5.0, v/v/v/v) were used for independent pre-fractionation experiments; 500 mg in each separation of white tea ethyl acetate partition were fractionated. The suitability of the two solvent systems was pre-evaluated by electrospray mass-spectrometry (ESI-MS/MS) analysis for metabolite distribution and compared to the results of the CPC experimental data using specific metabolite partition ratio KD values, selectivity factors α, and resolution factors RS. After size-exclusion and semi-preparative reversed-phase liquid chromatography, 6.4 mg of R-EGCG-cThea and 2.9 mg of S-EGCG-cThea were recovered with purities over 95%. Further bioactivity evaluation showed that R- and S-EGCG-cThea possessed in vitro inhibition effects on α-glucosidase with IC50 of 70.3 and 161.7 µM, respectively.

The mechanisms of calcium mobilization by procyanidins, flavonols and flavonoids from Cecropia glaziovii Sneth in pulmonary endothelial cell cultures endorse its popular use as vasodilator phytomedicine.

The hypotensive and antihypertensive activities of the aqueous extract (AE) and butanolic fraction (ButF) isolated from Cecropia glaziovii Sneth have been demonstrated in previous studies in animal models. This study aimed to evaluate the molecular mechanism of action responsible for the vasodilatory effect of procyanidins, flavanols, and flavonoids found in C. glaziovii in endothelial cell culture. For this purpose, we analyzed the effect of procyanidin B2 and B3 compounds, catechin, epicatechin, orientin, isoorientin, and isovitexin in the mobilization of Ca2+ in rat endothelial cell cultures. Parallel associations with different antagonists were examined by considering the following in vivo hypotensive mechanisms: blockage of L-type calcium channels, action on ß-2 adrenergic receptors, and vasodilation via the nitric oxide pathway. All measurements of calcium mobilization were carried out by using the fluorescence measurement methodology in a Flexstation M3 spectrophotometer. The results indicate that some of the compounds have mixed actions, acting through different calcium mobilization pathways. The mobilization induced by such compounds significantly decreased when they were incubated with their corresponding antagonists. Taken together, our data suggest that the beneficial effects seen with the popular use of Cecropia glaziovii Sneth in pathological conditions, such as systemic arterial hypertension, seem to be related to the plant's hypotensive effect, very probably promoted by the actions of flavonols, flavonoids, and procyanidins, by different pathways of calcium mobilization.

Anti-Obesity Effect of Polygalin C Isolated from Polygala japonica Houtt. via Suppression of the Adipogenic and Lipogenic Factors in 3T3-L1 Adipocytes.

Obesity is a risk factor for metabolic diseases including type 2 diabetes, nonalcoholic steatohepatitis (NASH), heart diseases, and cancer. This study aimed to investigate the anti-obesity effect of Polygalin C (PC) isolated from Polygala japonica Houtt. in 3T3-L1 adipocytes. Based on Oil Red O assay results, PC significantly decreased lipid accumulation compared to the control. We found that PC suppressed adipogenesis transcription factors including peroxisome proliferator-activated receptor γ (PPAR γ) and CCAAT/enhancer-binding protein (C/EBP) α, and lipogenic factors such as sterol regulatory element-binding protein 1c (SREBP 1c) and fatty acid synthase (FAS), in 3T3-L1 adipocytes using Western blotting and real-time polymerase chain reaction (PCR). Moreover, PC inhibited the differentiation of 3T3-L1 cells by regulating the AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) and mitogen-activated protein kinase/protein kinase B (MAPK/Akt) signaling pathways. Additionally, we confirmed that PC inhibited early adipogenesis factors C/EBP ß and C/EBP δ. Therefore, PC inhibited adipogenesis and lipogenesis in vitro. Thus, PC appears to exert potential therapeutic effects on obesity by suppressing lipid metabolism.

Changes in the Antioxidative Activity and the Content of Phenolics and Iridoids during Fermentation and Aging of Natural Fruit Meads.

The aim of the study was to investigate changes in the content of biologically active compounds during the fermentation and aging of natural meads with the addition of three Cornelian cherry juices from three cultivars: 'Koralovyi', 'Podolski' and 'Yantarnyi', in the amount of 10% v/v. After the fermentation process the content of gallic and ellagic acids significantly increased, in relation to wort. Whereas the greatest losses were observed among unstable anthocyanins. The three-month aging process also reduced the content of the analyzed compounds except for ellagic acid, the content of which increased by up to 90%. The content of biologically active compounds, including iridoids and antioxidant phenolics, are constantly changing in the process of fermentation and aging of fruit meads. The studies proved that the addition of Cornelian cherry juice allows significantly enriched classic meads with new biologically active compounds, such as: exceptional iridoids (loganic acid, cornuside, loganine, sweroside), flavonols, phenolic acids and anthocyanins.

Validation of a high-throughput method for the quantification of flavanol and procyanidin biomarkers and methylxanthines in plasma by UPLC-MS.

Nutritional biomarkers are critical tools to objectively assess intake of nutrients and other compounds from the diet. In this context, it is essential that suitable analytical methods are available for the accurate quantification of biomarkers in large scale studies. Recently, structurally-related (-)-epicatechin metabolites (SREMs) and 5-(3',4'-dihydroxyphenyl)-γ-valerolactone metabolites (gVLMs) were identified as biomarkers of intake of flavanols and procyanidins, a group of polyphenol bioactives. This study aimed at validating a high throughput method for the quantification of SREMs and gVLMs in plasma along with methylxanthines (MXs), dietary compounds known to interact with flavanol and procyanidin effects. To accomplish this, a full set of authentic analytical standards were used to optimize a micro solid phase extraction method for sample preparation coupled to HPLC-MS detection. Isotopically-labelled standards for all analytes were included to correct potential matrix effects on quantification. Average accuracies of 101%, 93% and 103% were obtained, respectively, for SREMs, gVLMs and MXs. Intra- and inter-day repeatability values were <15%. The method showed linear responses for all analytes (>0.993). Most SREMs and gVLMs had limits of quantifications <5 nM while limits of quantification of MXs were 0.2 µM. All analytes were stable under different tested processing conditions. Finally, the method proved to be suitable to assess SREMs, gVLMs and MXs in plasma collected after single acute and daily intake of cocoa-derived test materials. Overall, this method proved to be a valid analytical tool for high throughput quantification of flavanol and procyanidin biomarkers and methylxanthines in plasma.

Evaluation of Antioxidant, Anti-Inflammatory and Antityrosinase Potential of Extracts from Different Aerial Parts of Rhanterium suaveolens from Tunisia.

The genus Rhanterium (Asteraceae) is a widely distributed medicinal plant throughout western North Africa and some Rhanterium species are used in folk medicine. The aim of research was to investigate methanolic extracts from different parts (flowers, leaves, and stems) of Tunisian Rhanterium suaveolens as potential sources of bioactive products useful for healthy purposes. In particular, were analyzed the phenolic composition of these extracts and their antioxidant, anti-inflammatory, and anti-tyrosinase properties. The phytochemical analyses were performed using standard colorimetric procedures, HPLC-DAD and HPLC-DAD-ESI-MS. Then, several in vitro cell-free assays have been used to estimate the antioxidant/free radical scavenging capability of the extracts. Moreover, in vitro, and in vivo anti-melanogenesis activities of these extracts were tested, respectively, with the tyrosinase inhibition assay and the Zebrafish embryo model. Finally, the anti-inflammatory potential of these extracts in an in vitro model of acute intestinal inflammation in differentiated Caco-2 cells was evaluated. The R. suaveolens extracts under study appeared particularly rich in flavonols and hydroxycinnamic acids and all extracts appeared endowed with good antioxidant/free radical scavenging properties, being the flower extracts slightly more active than the others. Moreover, R. suaveolens flowers extract was able to inhibit in vitro tyrosinase activity and exhibited bleaching effects on the pigmentation of zebrafish embryos. Furthermore, all extracts showed good anti-inflammatory activity in intestinal epithelial cells as demonstrated by the inhibition of TNF-α-induced gene expression of IL-6 and IL-8. R. suaveolens aerial parts may be considered as a potential source of whitening agents, as well as of agents for the treatment of disorders related to oxidative stress and inflammation.

An RP-LC-UV-TWIMS-HRMS and Chemometric Approach to Differentiate between Momordicabalsamina Chemotypes from Three Different Geographical Locations in Limpopo Province of South Africa.

Momordica balsamina leaf extracts originating from three different geographical locations were analyzed using reversed-phase liquid chromatography (RP-LC) coupled to travelling wave ion mobility (TWIMS) and high-resolution mass spectrometry (HRMS) in conjunction with chemometric analysis to differentiate between potential chemotypes. Furthermore, the cytotoxicity of the three individual chemotypes was evaluated using HT-29 colon cancer cells. A total of 11 molecular species including three flavonol glycosides, five cucurbitane-type triterpenoid aglycones and three glycosidic cucurbitane-type triterpenoids were identified. The cucurbitane-type triterpenoid aglycones were detected in the positive ionization mode following dehydration [M + H - H2O]+ of the parent compound, whereas the cucurbitane-type triterpenoid glycosides were primarily identified following adduct formation with ammonia [M + NH4]+. The principle component analysis (PCA) loadings plot and a variable influence on projection (VIP) analysis revealed that the isomeric pair balsaminol E and/or karavilagen E was the key molecular species contributing to the distinction between geographical samples. Ultimately, based on statistical analysis, it is hypothesized that balsaminol E and/or karavilagen E are likely responsible for the cytotoxic effects in HT-29 cells.

A novel acylated flavonol tetraglycoside and rare oleanane saponins with a unique acetal-linked dicarboxylic acid substituent from the xero-halophyte Bassia indica.

In recent years, the scientific interest and particularly the economic significance of halophytic plants has been highly demanding due to the medicinal and nutraceutical potential of its bioactive compounds. A xero-halophyte Bassia indica is deemed to be a very cheap source of natural entities without chemical or biological investigation. In this context, a new acylated flavonol tetraglycoside, kaempferol-3-O-ß-d-glucopyranosyl-(1→6)-O-[ß-D-galactopyranosyl-(1→3)-2-O-trans-feruloyl-α-L-rhamnopyranosyl-(1→2)]-ß-D-glucopyranoside (14), together with rare occurring flavonol triglycoside, isorhamnetin-3-O-ß-d-glucopyranosyl-(1→6)-O-[α-L-rhamnopyranosyl-(1→2)]-ß-D-glucopyranoside (15), were isolated from the aqueous methanol extract of the aerial parts of B. indica. The study also reported an optimal separation and characterization of a new seco-glycosidic oleanane saponin with 2'R,3'S stereocenters, identified as (2'R,3'S)-3-O-[2'-hydroxy-3'-(2"-O-glycolyl)-oxo-propionic acid-ß-D-glucuronopyranosyl]-28-O-ß-D-glucopyranosyl-olean-12-en-3ß-ol-28-oic acid (17), in addition to its derivative, 3-O-[2'-(2"-O-glycolyl)-glyoxylyl-ß-D-glucuronopyranosyl]-28-O-ß-d-glucopyranosyl-olean-12-en-3ß-ol-28-oic acid (16). The structures of all isolated compounds were elucidated based on 1D, 2D NMR, and HR-MS analysis, as well as comparing with similar derivatives published in the literature. Furthermore, thirteen known compounds were isolated and identified as ß-sitosterol (1), vanillic acid (2), o-hydroxybenzoic acid (3), р-hydroxybenzoic acid (4), 6,7-dihydroxycoumarin (5), methyl caffeate (6), caffeic acid (7), quercetin (8), uracil (9), thymidine (10), tachioside (11), isorhamnetin-3-O-ß-D-glucopyranoside (12), kaempferol-3-O-rutinoside (13). The anticholinesterase activity of all isolated compounds was evaluated.

Flavonol glycosides and phenylpropanoid glycosides with inhibitory effects on microglial nitric oxide production from Neoshirakia japonica.

Five new flavonol glycosides (1-5), one new phenylpropanoid glycoside (6), and nine known glycosides (7-15) were isolated from the stems and leaves of Neoshirakia japonica. The structures of the new compounds were determined by detailed analysis of spectroscopic data (HRESIMS, 1D and 2D NMR) and acid hydrolysis experiment. The antineuroinflammatory effects of all the isolates were evaluated by inhibiting NO production against LPS-induced BV-2 microglial cells. Compounds 1, 8, and 9 showed more potent inhibitory activities with IC50 values of 2.7, 5.5, and 4.1 µM, respectively, than that of the positive control minocycline (IC50 = 15.6 µM), while compounds 7 (IC50 = 17.0 µM) and 10 (IC50 = 24.3 µM) also displayed inhibitory activities to a certain degree.

Phytochemical Profiling and Biological Activity of the Australian Carnivorous Plant, Drosera magna.

Phytochemical profiling was undertaken on the crude extracts of Drosera magna to determine the nature of the chemical constituents present. In total, three new flavonol diglycosides (1-3), one new flavan-3-ol glycoside (4), and 12 previously reported compounds of the flavonol (5, 9), flavan-3-ol (15), flavanone (8), 1,4-napthoquinone (6, 7, 13, 14), 2,3-dehydroxynapthalene-1,4-dione (10-12), and phenolic acid (16) structure classes were isolated and identified. Compounds 1-9, 13, 17, and 18 were assessed for antimicrobial activity, with compounds 6, 7, 8, and 9 showing significant activity. Compounds 1, 2, and 6 were also evaluated for anthelmintic activity against larval forms of Hemonchus contortus, with compound 6 being active.

Isolation and structure elucidation of a new flavonol glycoside from Sabia Parviflora.

A new flavonol glycoside named Sabiapside A (1), along with four known compounds, quercetin-3-O-gentiobioside (2), camellianoside (3), isobariclisin-3-O- rutinoside (4), tsubakioside A (5), was isolated from Sabia parviflora. Their structures were elucidated by extensive spectroscopic analysis including MS, UV, IR and NMR data. The antioxidant activities of these glycosides evaluated by ABTS+ and DPPH radical scavenging reaction was higher than that of vitamin C used as the reference antioxidant.

Four new flavonol glycosides from the leaves of Ginkgo biloba.

Four new flavonol glycosides, 5, 7, 5'-trihydroxy-3', 4'-dimethoxyflavonol-3-O-α-L-rhamnopyranosyl-(1→6)-ß-D-glucopyranoside (1), quercetin 3-O-(6-trans-feruloyl)-ß-D-glucopyranosyl-(1→2)-α-L-rhamnopyranoside (2), kaempferol 3-O-(6-trans-caffeoyl)-ß-D-glucopyranosyl-(1→2)-α-L-rhamnopyranoside (3), myricetin 3-O-(6-trans-p-coumaroyl)-ß-D-glucopyranosyl-(1→2)-α-L-rhamnopyranoside (4), together with nine known flavonoids and two known lignans, were isolated from the leaves of Ginkgo biloba. Their structures were determined by extensive spectroscopic analyses. Their cardioprotective effects against H2O2-induced apoptosis in H9c2 cells were also evaluated. The flavonol glycosides had stronger activity than the acylated flavonol glycosides at the concentration of 50 µM.

A new anti-inflammatory flavonoid glycoside from tetraena aegyptia.

The chromatographic reinvestigation the methanol extract of Tetraena aegyptia led to the separation of a new flavonoid glycoside, isorhamnetin-3-O-[2```,3```-O-isopropylidene-α-L-rhamnopyranosyl]-(1```→6``)-O-ß-D-glucopyranoside (1), together with two known flavonoids, isorhamnetin (2) and isorhamnetin-3-O-glucoside (3), isolated for the first time from the plant. The new compound was evaluated for the anti-inflammatory activity by using LPS-induce RAW 264.7 cells model. Compound 1 showed significant inhibitory effect on NO release. ELISA assay showed a pronounced effect of 1 on the secretion of cytokines IL-6 and TNF-α, in a dose-dependent manner. Consistent results were obtained by qRT-PCR which revealed that compound 1 markedly reduced the mRNA expression of IL-6 and TNF-α. Together these data, we demonstrated the anti-inflammatory activity of compound 1.

New phenylpropanoid-substituted and benzyl-substituted flavonols from Alangium chinense.

Two previously undescribed flavonols with phenylpropanoid or benzyl substitution, named alangsine A (1), and alangsine B (2), together with four known compounds (3-6) were isolated from the leaves of Alangium chinense. Alangsine A was a racemic mixture, which was further separated into two enantiomers via high-performance liquid chromatography on a chiral column. The absolute configurations of the enantiomer pairs were deduced from the circular dichroism (CD) spectra. The activity of the isolated compounds towards neuronal excitability was examined.

Novel insights on the multi-functional properties of flavonol glucosides from red onion (Allium cepa L) solid waste - In vitro and in silico approach.

Flavonol glucosides was extracted from red onion solid waste (ROSW) and multi-functional properties were determined to develop alternative strategy for therapeutic beneficiation and utilisation as functional food. The major flavonol glucosides extracted from ROSW were confirmed as quercetin-3, 4'-O-diglucoside (QDG), quercetin-3-O-glucoside (isoquercetin), quercetin-4'-O-glucoside (spiraeoside), isorhamnetin- 4'-glucoside (IMG), quercetin glycoside (QG), and quercetin (Q) using a combination of chromatographic, spectroscopic and scientific literature data. The ROSW solvent fractions and extracted flavonol glucosides showed significant antioxidant effect with DPPH, ABTS, FRAP, and ORAC radical scavenging assays. The in vitro and in silico study revealed that the QG, QDG, isoquercetin, and spiraeoside from ROSW exhibited potent α-glucosidase, tyrosinase and xanthine oxidase enzyme inhibitory activity. In addition, QG, QDG, isoquercetin, and spiraeoside showed potent anticancer effect on HeLa cancer lines. Considering these results, the utilization of ROSW and their flavonol glucosides might be helpful for developing potential antioxidant, anticancer and enzyme inhibitory agents.

Simultaneous Preparation of Abundant Flavonol Triglycosides from Tea Leaves.

Flavonol glycosides are important components of tea leaves, contributing to the bioactivities as well as bitterness and astringency of tea. However, the standards of many flavonol triglycosides are still not available, which restricts both sensory and bioactivity studies on flavonol glycosides. In the present study, we established a simultaneous preparation method of seven flavonol triglycoside individuals from tea leaves, which consisted of two steps: polyamide column enrichment and preparative HPLC isolation. The structures of seven flavonol triglycoside isolates were identified by mass and UV absorption spectra, four of which were further characterized by nuclear magnetic resonance spectra, namely, quercetin-3-O-glucosyl-rhamnosyl-glucoside, quercetin-3-O-rhamnosyl-rhamnosyl-glucoside, kaempferol-3-O-glucosyl-rhamnosyl-glucoside and kaempferol-O-rhamnosyl-rhamnosyl-glucoside. The purities of all isolated flavonol triglycosides were above 95% based on HPLC, and the production yield of total flavonol glycosides from dry tea was 0.487%. Our study provides a preparation method of flavonol triglycosides from tea leaves, with relatively low cost of time and solvent but high production yield.

Flavanols and triterpenoids from Myrianthus arboreus ameliorate hyperglycaemia in streptozotocin-induced diabetic rats possibly via glucose uptake enhancement and α-amylase inhibition.

Myrianthus arboreus is use traditionally as an antidiabetic agent in Ghana. We reported the in vivo antidiabetic activity of its 70 % ethanol stem bark extract (MAB) which we found to be strongly concentrated in its EtOAc fraction using glucose uptake and enzyme inhibitory assays. The present study sought to investigate the in vivo hypoglycaemic and anti-hyperlipidaemic activity of this ethyl acetate fraction of MAB (MAB-EtOAc, 50 and 100 mg/kg) in streptozotocin (STZ)-induced diabetic rats for 21 days, isolate and evaluate the bioactive constituents responsible for the antidiabetic activity. In silico pharmacokinetic and toxicity properties of the most active compound was also determined. MAB-EtOAc significantly (p < 0.001) reduced the blood glucose levels while normalizing considerably the altered serum lipid parameters of the diabetic rats which was comparable to glibenclamide (5 mg/kg). Chemical investigation of MAB-EtOAc led to the isolation of seven known compounds including three flavanols which are reported for the first time in the plant: epicatechin (1), epigallocatechin (2), dulcisflavan (3), euscaphic acid (4), tormentic acid (5), sitosterol-3-O-ß-d-glucopyranoside (6) and arjunolic acid (7). The compounds markedly inhibited the action of α-amylase and, except for 4 and 6, which stimulated considerably glucose uptake in C2C12 cells. Compounds 2, 3, 5, 6 and 7 which were further evaluated in STZ-induced diabetic rats demonstrated hypoglycaemic and anti-hyperlipidaemic activities which, however, were not comparable with MAB-EtOAc. Compound 3, the most active compound was predicted to be non-toxic, non-mutagenic, has reasonable oral bioavailability and a decent substrate for further drug development. The findings of this study show that the isolated compounds may contribute to the antidiabetic activity of M. arboreus and could serve as marker compounds for the quality control of herbal medicines that would be made from the plant.

Acetic acid buffer as extraction medium for free and bound phenolics from dried blackcurrant (Ribes nigrum L.) skins.

The aim of this study was to investigate the effects of different solvent and extraction temperatures on the free and bound phenolic compounds and antioxidant activity of dried blackcurrant skins (DBS). Apart from acetic acid buffer solution, different solvent systems, including water, methanol, and mixtures of methanol/water, were also employed and the effects of solvent and temperature (30 and 50 °C) on the free and bound forms of anthocyanins, hydroxycinnamic acids, and flavonols yield were assessed. The results showed that among all solvents, acetic acid buffer resulted in the highest free anthocyanin content (1,712.3 ± 56.1 mg/100 g) (P < 0.05) after 2 hr extraction at 50 °C from DBS, while lower amounts of bound anthocyanins and anthocyanidins were detected after acid hydrolysis. Acetic acid buffer extracts exhibited the highest free hydroxycinnamic acid content (268.0 ± 4.5 mg/100 g), total phenolic content (3702.2 ± 259.3 mg GAE/100 g), and DPPH activity (60.7 ± 2.0% of inhibition). However, their free flavonol content was slightly lower (60.2 ± 0.8 mg/100 g) compared to 100% methanol at 30 and 50 °C (71.4 ± 1.5 mg/100 g and 71.5 ± 6.2 mg/100 g, respectively). Two-way ANOVA indicated interactions between solvent and temperature (P < 0.05), which suggested that the relationship between solvent and phenolic compounds depends on the extraction temperature. PRACTICAL APPLICATION: Overall, acetic acid buffer is more environmental friendly, efficient, and cost effective than other solvents, thus, offering an improved extraction method for phytochemicals as valuable ingredients for nutraceutical applications, from underutilized dried blackcurrant skins (DBS).