Phenolic composition and bioactivity of Ribes magellanicum fruits from southern Patagonia.

Eight Ribes magellanicum collections from three different places in southern Patagonia were compared for content of different groups of phenolics, antioxidant capacity and inhibition of enzymes related to metabolic syndrome (α-amylase, α-glucosidase and pancreatic lipase). The sample with the highest antioxidant capacity was assessed for glutathione (GSH) synthesis stimulation in human gastric adenocarcinoma (AGS) cells. The chemical profile was determined by high performance liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS) and the main phenolics were quantified. The samples from Navarino Island and Reserva Nacional Magallanes showed higher content of anthocyanins and caffeoylquinic acid, with better activity towards α-glucosidase and antioxidant capacity. A sample from Omora (Navarino Island), significantly increased intracellular GSH content in AGS cells. Some 70 compounds were identified in the fruit extracts by HPLC-MS/MS. The glucoside and rutinoside from delphinidin and cyanidin and 3-caffeoylquinic acid were the main compounds. Different chemical profiles were found according to the collection places.

Antioxidant capacity and inhibition of metabolic syndrome-associated enzymes by Cryptocarya alba fruits.

The fruits of the native tree Cryptocarya alba Mol. (Lauraceae), known as "peumo" were consumed by the Mapuche Amerindians in Chile both raw and after boiling. The aim of this work was to compare the content of phenolic, procyanidins, antioxidant capacity and inhibition of enzymes related with metabolic syndrome (α-glucosidase, α-amylase and pancreatic lipase) from the phenolic enriched extracts (PEEs) of peumo fruits. Fruits were collected during two years in three different places in central Chile and were investigated raw, boiled, and after separation into cotyledons and peel. The water resulting from the fruit decoction was also analyzed. The composition of the PEE was assessed by HPLC-DAD-MS/MS and the main compounds were quantified by HPLC. The strong inhibitory effect on α-glucosidase, with IC50 values below 1 µg/mL for several samples, was related, at least in part, to the content of 3-caffeoylquinic acid, 5-caffeoylquinic acid and (-)-epicatechin. The effect of the PEE on pancreatic lipase is of interest and can be partially explained by the (-)-epicatechin content. PCA analyses showed a clear separation of the samples according to the fruit parts and processing. However, no differences by geographic origin were observed. The activity of peumo PEEs on enzymes related to metabolic syndrome and its antioxidant capacity support further studies on the health promoting properties of this native Chilean food plant.

Phenolic Composition, Antioxidant Capacity, and α-Glucosidase Inhibition of Boiled Green Beans and Leaves from Chilean Phaseolus vulgaris.

The tender green pods of the common bean (Phaseolus vulgaris L.) are marketed fresh, frozen or canned. The main bean accessions cultivated for green pods in central Chile are Arroz, Magnum, Peumo and the introduced Malibú. Little is known about the identity of phenolics in the processed pods or in the boiled bean leaves. Raw leaves from Chilean bean landraces showed a strong inhibition towards the enzyme α-glucosidase, associated with flavonoids and caffeoyl malic acid content. The aim of this work was to assess the phenolic composition, antioxidant capacity and activity towards α-glucosidase of boiled leaves and green pods from selected bean landraces. The study was performed with four green pods samples and six leaf accessions, respectively. The leaves included the continuous growth bean Ñuño (red seed and black seed). Antioxidant capacity and inhibition of α-glucosidase were measured. The main phenolics were identified by comparison with standards and were quantified using calibration curves. The extracts of most boiled green pods inhibited α-glucosidase while the leaves were inactive. The content of phenolics in the boiled pods is low, with rutin and quercetin 3-O-glucuronide as the main constituents. In boiled leaves, the main phenolics were quercetin 3-O-glucuronide and kaempferol 3-O-glucuronide. The main flavonoids and caffeoyl malic acid in leaves decreased after boiling. Boiling affected the phenolic profile, reducing antioxidant capacity and glucosidase inhibition, highlighting the importance of characterizing foods as they are ingested.

Iridoids and polyphenols from chilean Gaultheria spp. berries decrease the glucose uptake in Caco-2 cells after simulated gastrointestinal digestion.

Berries are rich food sources of potentially health-beneficial (poly)phenols. However, they may undergo chemical modifications during gastrointestinal digestion. The effect of simulated gastrointestinal digestion on the content and composition of secondary metabolites from Gaultheria phillyreifolia and G. poeppigii berries was studied. The influence of the digested extracts on the in vitro metabolism and absorption of carbohydrates was evaluated. After simulated digestion, 31 compounds were detected by UHPLC-DAD-MS. The total content of anthocyanins decreased by 98-100%, flavonols by 44-56%, phenylpropanoids by 49-75% and iridoids by 33-45%, the latter showing the highest stability during digestion. Digested extracts inhibited α-glucosidase (IC50 2.8-24.9 µg/mL) and decreased the glucose uptake in Caco-2 cells by 17-28%. Moreover, a decrease in the mRNA expression of glucose transporters SGLT1 (38-92%), GLUT2 (45-96%), GLUT5 (28-89%) and the enzyme sucrase-isomaltase (82-97%) was observed. These results show the effect of simulated gastrointestinal digestion on the content and composition of Gaultheria berries.

Antiglycating Effect of Phenolics from the Chilean Currant Ribes cucullatum under Thermal Treatment.

Numerous dietary polyphenols possess antiglicating activity, but the effects of thermal treatment on this activity are mostly unknown. The effect of thermal treatment in the antiglycating activity of polyphenolic enriched extracts (PEEs) from Ribes cucullatum towards glyoxal-induced glycation of sarcoplasmic proteins was assessed. Sarcoplasmic proteins from chicken, beef, salmon, and turkey, were incubated 2 h at 60 °C with and without glyoxal and different concentrations of PEEs (0.25, 0.5, 1, and 5 mg/mL). The antiglycating activity was evaluated by: (1) Lys and Arg consumption, (2) Carboxymethyl lysine (CML) generation, and (3) lipid-derived electrophiles inhibition in a gastric digestion model. Protective effects were observed against CML generation in proteins and a decrease of electrophiles in the gastric digestion model. A dose-dependent consumption of Lys and Arg in proteins/PEEs samples, indicated the possible occurrence of quinoproteins generation from the phenolics. Protein/PEEs incubations were assessed by: (1) High pressure liquid chromatography analysis, (2) Gel electrophoresis (SDS-PAGE), and (3) Redox cycling staining of quinoproteins. Protein/PEEs incubations produced: (1) Decrease in phenolics, (2) increase of protein crosslinking, and (3) dose-dependent generation of quinoproteins. We demonstrate that phenolic compounds from R. cucullatum under thermal treatment act as antiglycating agents, but oxidative reactions occurs at high concentrations, generating protein crosslinking and quinoproteins.

Phenolic composition, antioxidant capacity and α-glucosidase inhibitory activity of raw and boiled Chilean Araucaria araucana kernels.

The Araucaria araucana kernels are a traditional food in southern Chile and Argentina. The aim of this work was to determine the composition of the phenolic-enriched extracts (PEEs) of the boiled kernels as well as their antioxidant capacity, inhibitory activity on metabolic syndrome-associated enzymes and effect on postprandial oxidative stress in a simulated gastric digestion model. The PEEs composition was assessed by HPLC-DAD-MS/MS. The main PEEs constituents were catechin and epicatechin in the unbound form, while hydroxybenzoic acids occurred mainly in the bound form. The unbound phenolics from boiled kernels showed significant correlations with DPPH, FRAP, TEAC (Pearson's r of 0.481, 0.331 and 0.417, respectively) and lipid peroxidation (r = 0.381) and were more active than the bound phenolics. The extracts were highly active against α-glucosidase (IC50: 0.33-3.15 µg/mL) and reduced lipoperoxidation. Traditional processing increases the flavan-3-ol content. Our results suggest that this traditional food has potential health promoting properties.

Phenolics from the Bolivian highlands food plant Ombrophytum subterraneum (Aspl.) B. Hansen (Balanophoraceae): Antioxidant and α-glucosidase inhibitory activity.

The Balanophoraceae Ombrophytum subterraneum is an endemic highland food plant occurring in Bolivia, northern Argentina and Chile. The upper part of this parasitic plant is eaten fresh. The aim of this work was to characterize the compounds occurring in the edible part and to assess any differences between the inflorescence and tuber. Ethanol extracts of the different plant parts were analyzed for antioxidant activity by the ORAC, TEAC, FRAP, CUPRAC and DPPH methods as well as for the effect on enzymes related to metabolic syndrome (α-amylase, α-glucosidase and pancreatic lipase). The main constituents were isolated by a combination of gel permeation in Sephadex LH-20 and countercurrent chromatography (CCC). Five compounds were isolated and fully identified by spectroscopic and spectrometric means. The new 3',5,5',7-tetrahydroxyflavanone 7-O-ß-D-1 â†’ 6 diglucoside was isolated for the first time. HPLC-ESI-MS/MS analysis allowed the identification of 19 compounds, including flavanones, flavanols, flavonols, dehydroflavonols and lignans, mainly as glycosides. A strong inhibition towards α-glucosidase was observed for the edible parts (IC50: 1.46 µg/mL) as well as for the tuber and inflorescence (IC50: 1.56 µg/mL and 0.87 µg/mL, respectively). A significant correlation was established between the total phenolic and the antioxidant capacity of the extracts as well as with the content of the new flavanone diglucoside. This is the first comprehensive report on the naturally occurring antioxidants and enzyme inhibitors from this native highland food resource.

Isolation and characterization of secondary metabolites from Gaultheria tenuifolia berries.

Gaultheria berries (Ericaceae) are consumed as food or used in folk medicine throughout the world. In the present study, Gaultheria tenuifolia berries were studied to describe their polyphenol and iridoid composition, aroma volatiles, and cytoprotective effects. In total, 14 metabolites were isolated using a combination of countercurrent chromatography and Sephadex LH-20, namely, cyanidin-3-O-ß-galactoside, cyanidin-3-O-ß-arabinoside, 3-O-caffeoylquinic acid, 5-O-caffeoylshikimic acid, quercetin, quercetin-3-O-ß-glucuronide, quercetin-3-O-ß-rutinoside, quercetin-3-O-ß-glucoside, quercetin-3-O-ß-arabinoside, quercetin-3-O-ß-rhamnoside, 6α-hydroxydihydromonotropein-10-trans-cinnamate, monotropein-10-trans-cinnamate, and an (epi)-catechin dimer and trimer. Other flavan-3-ols, proanthocyanidins, and iridoids were tentatively identified by spectroscopic and spectrometric means in the fruit extracts. The tentative volatile organic compound characterization pointed to methyl salicylate as responsible for the aroma of this species. The extracts showed significant cytoprotective effects in an oxidative stress model in human gastric epithelial cells. This is the first report on the isolation, characterization, and potential biological activity of secondary metabolites from G. tenuifolia berries and insights on its possible application as a functional food. PRACTICAL APPLICATION: Berries are desirable fruit species because of their phytochemical composition and pleasant taste. Gaultheria berries are special due to their high content of iridoids and the presence of salicylic acid derivatives. Aroma of native berries is relevant for the development of new products reflecting the local identity and use of fruits. The present work involves cooperation of academia and industry on the constituents of the native products. The results provided in this article could be useful for the introduction of this species in the food and nutraceutical industries.

Iridoids and Amino Acid Derivatives from the Paraguayan Crude Drug Adenocalymma marginatum (ysypó hû).

The crude drug ysypó hû (Adenocalymma marginatum DC., Bignoniaceae) is used traditionally by the Guarani of Eastern Paraguayan as a male sexual enhancer. The aim of the present study was to identify the main constituents of the crude drug and to evaluate the in vitro inhibitory activity towards the enzyme phosphodiesterase-5 (PDE-5). The main compounds were isolated by counter-current chromatography (CCC). The metabolites were identified by spectroscopic and spectrometric means. The chemical profiling of the extracts was assessed by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS). The crude extract and main isolated compounds were tested for their PDE-5 inhibitory activity using commercial kits. The iridoid theviridoside and 4-hydroxy-1-methylproline were isolated as the main constituent of the crude drug. Four chlortheviridoside hexoside derivatives were detected for the first time as natural products. Chemical profiling by HPLC-MS/MS led to the tentative identification of nine iridoids, six phenolics, and five amino acids. The crude extracts and main compounds were inactive towards PDE-5 at concentrations up to 500 µg/mL. Iridoids and amino acid derivatives were the main compounds occurring in the Paraguayan crude drug. The potential of ysypó hû as a male sexual enhancer cannot be discarded, since other mechanisms may be involved.

Andean Prumnopitys Andina (Podocarpacae) Fruit Extracts: Characterization of Secondary Metabolites and Potential Cytoprotective Effect.

The fruits from the Chilean Podocarpaceae Prumnopitys andina have been consumed since pre-Hispanic times. Little is known about the composition and biological properties of this fruit. The aim of this work was to identify the secondary metabolites of the edible part of P. andina fruits and to assess their antioxidant activity by means of chemical and cell-based assays. Methanol extracts from P. andina fruits were fractionated on a XAD7 resin and the main compounds were isolated by chromatographic means. Antioxidant activity was determined by means of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing power (FRAP), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. The cytoprotective activity of the extract against oxidative and dicarbonyl stress was evaluated in human gastric epithelial cells (AGS). The total intracellular antioxidant activity (TAA) of the extract was determined in AGS cells. The inhibition of meat lipoperoxidation was evaluated under simulated gastric digestion conditions. Rutin, caffeic acid ß-glucoside and 20-hydroxyecdysone were identified as major components of the fruit extract. Additional compounds were identified by high-performance liquid chromatography diode-array detector mass spectrometry (HPLC-DAD-MSn) and/or co-injection with standards. Extracts showed dose-dependent cytoprotective effects against oxidative and dicarbonyl-induced damage in AGS cells. The TAA increased with the pre-incubation of AGS cells with the extract. This is the first report on the composition and biological activity of this Andean fruit.

Polyphenol Composition and (Bio)Activity of Berberis Species and Wild Strawberry from the Argentinean Patagonia.

The Argentinean Patagonia berries Berberis microphylla, Berberis darwinii, and Fragaria chiloensis ssp. chiloensis f. patagonica were investigated for their polyphenol content and composition by means of liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry. The in vitro antioxidant activity and inhibition of metabolic syndrome-associated enzymes (α-glucosidase, α-amylase, and lipase) of the fruit extracts was assessed. The most complex polyphenol profile was found in the Berberis samples, with 10 anthocyanins, 27 hydroxycinnamic acids, 3 proanthocyanidins, 2 flavan-3-ol, and 22 flavonols. Fragaria presented four anthocyanins, nine ellagitannins, two proanthocyanidin dimers, one flavan-3-ol, and five flavonols. The Berberis samples showed the best antioxidant capacity, while Fragaria displayed better activity against α-glucosidase and lipase. The phenolic content and composition of the Argentinean Patagonia berries was similar to that reported for Chilean samples but with some chemical differences between Eastern (Argentina) and Western (Chile) Patagonia. The data obtained supports the consumption of these berries as sources of beneficial polyphenols.

Phenolic, oxylipin and fatty acid profiles of the Chilean hazelnut (Gevuina avellana): Antioxidant activity and inhibition of pro-inflammatory and metabolic syndrome-associated enzymes.

Roasted cotyledons of the Chilean hazelnut (Gevuina avellana) are appreciated as snacks. The aim of our work was to assess the fatty acid, oxylipin and phenolic composition using gas chromatography (GC) coupled to mass spectrometry (MS), ultra- high performance liquid chromatography (UHPLC) coupled to MS and HPLC coupled to diode array detector (HPLC-DAD). Additionally, various antioxidant activities were assessed. The inhibition of α-glucosidase, α-amylase, lipase, cyclooxygenases-1 and -2 (COX-1/COX-2), and lipoxygenase was determined. The main fatty acids were oleic and 7-hexadecenoic acids. Eight phytoprostanes and three phytofurans were identified and quantified. Hydroxybenzoic and hydroxycinnamic acids were the main phenolic compounds. Oils showed antioxidant activity determined by EPR, and inhibition of COX-1/COX-2. The statistical analysis showed that the roasting does not affect the composition of the samples. The occurrence of oxylipins in this species is reported for the first time. Chilean hazelnuts can be considered a source of health promoting compounds.

Effect of simulated gastrointestinal digestion on polyphenols and bioactivity of the native Chilean red strawberry (Fragaria chiloensis ssp. chiloensis f. patagonica).

The native Chilean red strawberry (Fragaria chiloensis spp. chiloensis f. patagonica) is a wild strawberry with high polyphenol content and antioxidant activity originating in central-southern Chile. The aim of the present work was to compare the composition and bioactivity of polyphenol-concentrated extracts (PCE) of the fruit, before and after simulated gastrointestinal digestion (GID). Twenty nine compounds were tentatively identified in the non-digested PCE. After GID, 26 and 23 compounds were detected, in the gastric and intestinal steps, respectively. The compounds that were more affected by the simulated GID were cyanidin hexoside, bis hexahydroxydiphenic acid (HHDP) hexosides, bis HHDP galloyl hexosides, apigenin hexoside, and quercetin dihexoside. Results show a decrease in the total phenolic content by 3.4% and 43% at the end of the gastric and intestinal steps, respectively. In the same way, the total flavonoid content decreased by 60.4% and 90.9% at the end of the gastric and intestinal step, respectively. Overall, the antioxidant activity decreased during the gastrointestinal process; as well as the inhibitory activity against α-glucosidase and lipase was reduced by the simulated digestion. These results are a first approach to understand the effects induced by the gastrointestinal digestion on the bioactivity and polyphenolic profile of this native fruit.

Patagonian berries as native food and medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Patagonia is the southernmost part of the South American continent including Chile and Argentina. Berries and wild fruits have been gathered by the native Patagonians as food and medicine for over 14,000 years. The economic potential of the native berries as health promoting and relevant sources of bioactive substances has become apparent with several studies in the last decades. AIM OF STUDY: This work aims to provide an insight into the ethnohistorical records of wild edible fruits from Patagonia starting with the archeobotanical studies to the contemporary use of the resources. The chemical and bioactivity studies on the native fruits are presented and discussed. METHODOLOGY: A search of electronic databases including Scopus, Scielo, Google Scholar, PubMed, ScienceDirect and SciFinder, as well as hand-search was carried out to perform an integrative review on the native Patagonian berries. RESULTS: The use of native berries as food and medicine by the ancient hunter-gatherer societies can be traced back to the early occupation of Patagonia. The same species used in prehistoric times are still used as food by the contemporary population in this area. Chemical and bioactivity studies have reported remarkable activities in several of the native berries, including calafate (Berberis spp.), native strawberry (Fragaria chiloensis), currants (Ribes spp.), Patagonian raspberries (Rubus spp.) and maqui (Aristotelia chilensis) fruits. The increasing demand for maqui and calafate led to the selection of varieties for commercial production. The fruit constituents show strong antioxidant and inhibitory effect towards enzymes associated with metabolic syndrome, including α-amylase, α-glucosidase and lipase. Some berry constituents exert anti-inflammatory effects in vitro. The phytochemicals identified include a wide array of phenolics of different structural skeletons. Changes in composition and bioactivity after simulated gastric and intestinal digestion, as well as colonic fermentation, have been reported in some Patagonian species. CONCLUSIONS: Patagonian berries are a relevant source of bioactive compounds with several health promoting properties. The long tradition of use and the interest of the population for their consumption has led to the development of some of this fruits as new potential crops. The ethnobotanical evidence shows a shared knowledge among the different indigenous communities on plant uses according to the local resources, and an integration of the ancient knowledge into the contemporary society. Other species are being investigated to get a more complete picture of the food and medicinal plants from Patagonia.

Antioxidant activity and the isolation of polyphenols and new iridoids from Chilean Gaultheria phillyreifolia and G. poeppigii berries.

The berries from the native Chilean Gaultheria phillyreifolia and G. poeppigii are appreciated for their sweet taste and aroma. Fruits from both species were investigated for their secondary metabolite composition and antioxidant activity. The extracts were submitted to membrane chromatography to separate anthocyanins from copigments. Four anthocyanins were isolated by counter-current chromatography (CCC) and identified as cyanidin galactoside, cyanidin arabinoside, delphinidin galactoside and delphinidin arabinoside. From the copigments, CCC allowed the separation of quercetin(Q)-3-arabinoside, Q-3-rutinoside Q-3-rhamnoside and 3-caffeoylquinic acid. Additionally, the iridoids monotropein-10-trans-coumarate, monotropein-10-trans-cinnamate and 6α-hydroxy-dihydromonotropein-10-trans-cinnamate were isolated. The latter two iridoids are reported here for the first time. Some 34 other compounds were tentatively identified by HPLC-DAD-ESI-MSn. The antioxidant activity showed differences between anthocyanins and copigments from both species. Main compounds were quantified and submitted to a Partial-Least Square Discriminant Analysis (PLS-DA). This is the first report on the isolation of phytochemicals from the selected Chilean Gaultheria species.

Antiproliferative and proapoptotic activities of aza-annulated naphthoquinone analogs.

1,4-Naphthoquinone derivatives have been widely documented with regard to their biological properties, and particularly their anticancer activities. In the 9,10-anthraquinone family, aza-annulation involving one of the carbonyl oxygen atoms has afforded more potent, possibly less toxic analogues. We recently carried out different modifications on the naphthoquinone skeleton to generate 3-chloro-2-amino- and 3-chloro-2-(N-acetamido)-1,4-naphthoquinone and 3,4-dihydrobenzo[f]quinoxalin-6(2H)-one derivatives. These three series of compounds were now tested against normal human fibroblasts and six human cancer cell lines. Some of the dihydrobenzoquinoxalinone derivatives were not only more potent than their 1,4-naphthoquinone counterparts, but also exhibited 10- to 14-fold selectivity between bladder carcinoma and normal cells and were equipotent with the non-selective reference drug used (etoposide). The fusion of an additional azaheterocycle to the 1,4-naphthoquinone nucleus modulates both the activity, selectivity and mechanism of action of the compounds. The electrochemical properties of selected compounds were evaluated in an attempt to correlate them with cytotoxic activity and mechanism of action. Finally, 3D-QSAR CoMFA and CoMSIA models were built on the AGS, J82, and HL-60 cell lines. The best models had values of r2pred = 0.815; 0.823 and 0.925. The main structural relationships found, suggest that acetylation and alkylation of the amino group with large groups would be beneficial for cytotoxic activity.

Male sexual enhancers from the Peruvian Amazon.

ETHNOPHARMACOLOGICAL RELEVANCE: Selected Peruvian Amazon plants are macerated into sugar cane distillates to prepare alcoholic beverages used to improve male sexual performance. The tree bark from Campsiandra angustifolia Spruce ex Benth (Fabaceae), Swartzia polyphylla DC (Fabaceae), Minquartia guianensis Aubl. (Olacaceae) and Thynantus panurensis (Bureau) Sandwith (Bignoniaceae) usually are used as crude drugs in mixtures of several ingredients. AIM OF STUDY: Describe the chemical composition of the most traded traditional male enhancer beverages, namely "Levántate Lazaro" and "Siete veces sin sacarla", and their single crude drug constituents, as well as their inhibitory activity towards the enzyme phosphodiesterase-5. The presence of pro-sexual drugs such as Sildenafil® and derivatives was assessed in the samples. MATERIALS AND METHODS: Single plant constituents and the preparation mixtures were purchased in the Mercado Belen (Iquitos, Peru). Chemical profiling was carried out by HPLC-DAD-ESI-MS/MS. The extracts were assessed for phosphodiesterase-5 inhibition. The occurrence of pro-sexual drugs was determined by HPLC-DAD-ESI-MS/MS. RESULTS: Chemical profiling allowed the identification of condensed tannins as the main constituents of C. angustifolia and S. polyphylla, hydrolysable tannins for M. guianensis, and C-glycosides for T. panurensis. The traditional preparations showed similar composition compared to the crude drugs. At 200 µg/mL, the traditional preparation "Levántate Lázaro" and "Siete veces sin sacarla" inhibited the phosphodiesterase-5 by 49.88% and 27.90%, respectively. No adulterations with pro-sexual drugs were found in the samples. From the crude drugs, low effect was found for the extracts of S. polyphylla and T. panurensis and high activity for C. angustifolia which inhibited the enzyme by 89.37% and 81.32% at 200 and 100 µg/mL, respectively. CONCLUSION: The traditional preparations used to improve sexual performance in the Peruvian Amazon showed activity as phosphodiesterase-5 inhibitors. The most active ingredient of the traditional preparations was C. angustifolia, with some contribution from T. panurensis. These results encourage additional studies, including animal models to confirm the male enhancer effect of the preparations.

Polyphenolic profile and antioxidant activity of meristem and leaves from "chagual" (Puya chilensis Mol.), a salad from central Chile.

The Bromeliaceae Puya chilensis Mol. is a native monocotyledonous food plant that can be found in central Chile. It is traditionally known as chagual. The tender basal part of the leaves, just starting from the meristem, are consumed as a salad. The aim of this work was to describe the phenolic content and composition of the meristem and leaves of chagual, as well as their antioxidant capacity and inhibitory activity against metabolic syndrome-associated enzymes. Samples of chagual, including two cultivated and three wild growing plants, were analyzed and compared for composition and bioactivity. From the phenolic enriched extract of the plant (PEE), 26 compounds were tentatively identified by HPLC-DAD-ESI-MSn, including 12 hydroxycinnamic acids and 14 flavonoids. The main compounds were identified as diferuloyl hexaric acid isomers and 5-p-Coumaroylquinic acid. The compounds were quantified in both meristem and leaves. The PEE content was up to ten times higher in the meristem than in the leaves, ranging from 0.18 to 124.08 mg/g PEE. The samples inhibited α-glucosidase, but did not show effect on α-amylase and pancreatic lipase. This is the first report on the polyphenol composition and bioactivity of the edible components of the chagual food plant.

Oligostilbenoids in Vitis vinifera L. Pinot Noir grape cane extract: Isolation, characterization, in vitro antioxidant capacity and anti-proliferative effect on cancer cells.

The following oligostilbenoids were isolated from extracts of Vitis vinifera L. Pinot Noir grape canes produced at a pilot-plant scale: (E)-ε-viniferin, (E)-resveratrol, (E)-piceatannol, ampelopsin A, vitisin B, pallidol, (E)-δ-viniferin, (E)-ω-viniferin, (E)-trans-cis-miyabenol C, isorhapontigenin, scirpusin A, and a new isomer named isoscirpusin A. The antioxidant capacity of the isolated stilbenoids was studied by three different assays, and their 50% inhibition concentration (IC50) against cancer cells was determined by MTT reduction assay. Besides (E)-resveratrol, stilbenoids have outstanding antioxidant capacity in the ORAC-FL assay. The strongest antiproliferative effect was observed for (E)-piceatannol and ampelopsin A against the bladder cancer cell line J82. (E)-Piceatannol has inhibitory effect on human lung cancer SK-MES-1 cells. Moreover, the whole extract has antiproliferative effect on all tested cell lines. In conclusion, beside (E)-resveratrol, grape cane extract contains oligostilbenoids with potential health benefits. This underexploited viticultural residue has the potential to produce valuable phytochemicals or ingredients in functional foods.

Colonic fermentation of polyphenols from Chilean currants (Ribes spp.) and its effect on antioxidant capacity and metabolic syndrome-associated enzymes.

The Chilean wild currants Ribes magellanicum and R. punctatum are a good source of polyphenols. Polyphenolic-enriched extracts (PEEs) from both species were submitted to in vitro colonic fermentation to assess the changes in phenolic composition, antioxidant capacity and inhibition of metabolic syndrome-associated enzymes. The phenolic profiles of the fermented samples showed significant changes after 24 h incubation. Nine metabolites, derived from the microbial fermentation, were tentatively identified, including dihydrocaffeic acid, dihydrocaffeoyl-, dihydroferuloylquinic acid, 1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol (3,4-diHPP-2-ol), among others. The content of anthocyanins and hydroxycinnamic acids was most affected by simulated colonic conditions, with a loss of 71-92% and 90-100% after 24 h incubation, respectively. The highest antioxidant capacity values (ORAC) were reached after 8 h incubation. The inhibitory activity against the enzyme α-glucosidase was maintained after the fermentation process. Our results show that simulated colonic fermentation exerts significant changes on the polyphenolic composition of these berries, modifying their health-promoting properties.