Effect of different concentrations of stem juice of Oxalis tuberosa Mol. and juice of the fruit of Gaultheria glomerata (Cav.) Sleumer on the antioxidant activity of the heat-treated functional beverage.

Functional beverages with added health benefits are popular among peoples and athletes because they help them recover faster from intense workouts and perform better overall. This research set out to determine how well heat-treated stem juice from Oxalis tuberosa Mol. "oca" and fruit juice from Gaultheria glomerata (Cav.) Sleumer "laqa-laqa" performed as an antioxidant in a functional drink. The "oca" stems and the "laqa-laqa" fruit were collected to obtain the juice. For this study, 30 semi-trained panellists used sensory evaluation to rate four treatments (Bo, B1, B2, and B3) with varying quantities of "oca" and "laqa-laqa" juice. The results concluded that the treatment B2, which included 300 ml of "oca" stem juice, 800 ml of "laqa-laqa" juice, 1000 ml of treated water, and 220 g of refined sugar, was given the highest score after a physicochemical evaluation of its colour, smell, taste, and overall appearance. Similarly, the results showed that the protein content increased by 1.38%, the fat content by 1.08%, the moisture percentage by 99.5%, the ash content by 1.82%, and the carbohydrate content by 6.22% after B2 treatment. Similarly, results revealed significant enhancement in antioxidant profiling such as total polyphenols: 1825 mg of gallic acid/100 g and antioxidant Activity: 89.56% µmol of trolox /100 g. In conclusion, due to its high energy content and antioxidant activity, it may be a viable nutritional option for athletes who engage in rigorous, frequent physical exertion.

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.

Human gastrointestinal metabolism of the anti-rheumatic fraction of Dianbaizhu (Gaultheria leucocarpa var. yunnanensis) in vitro: Elucidation of the metabolic analysis in gastric juice, intestinal juice and human intestinal bacteria by UPLC-LTQ-Orbitrap-MSn and HPLC-DAD.

The anti-rheumatic fraction (ARF), is responsible for the anti-inflammatory and analgesic effects of Dianbaizhu derived from the aerial part of Gaultheria leucocarpa var. yunnanensis (Ericaceae). The gastrointestinal metabolism of ARF was investigated in vitro through simulating a series of models-gastric juice, intestinal juice, and human intestinal bacteria, analyzed by HPLC-DAD and UPLC-LTQ-Orbitrap-MSn. ARF includes three categories: methyl salicylate glycosides, organic acids and the others. The primordial and metabolic components of ARF bio-transformed by simulated gastric fluid (36 and 13), intestinal fluid (29 and 7) and two human fecal bacteria (34 and 34, 40 and 25) were characterized, respectively. The methyl salicylate glycosides, MSTG-B, MSTG-A and gaultherin, with terminal-xylosyl-moiety in sugar chain were always being found in the whole gastrointestinal incubation processing. The metabolites were formed through hydrolysis of ester and glucosidic bond, as well as methylation, hydroxylation, acetylation, sulfation, reduction, decarboxylation, deglycosylation and glucuronidation. The metabolic conversion effect of the four index compounds, MSTG-B, MSTG-A, gaultherin, and chlorogenic acid by human intestinal bacteria exhibited much stronger. Those markers' variation in content-time curve in volunteer A gut flora were faster than that in volunteer B's. These results indicate that ARF is relatively stable in the gastrointestinal tract.

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.

Colonization and decomposition of salal (Gaultheria shallon) leaf litter by saprobic fungi in successional forests on coastal British Columbia.

The colonization of leaf litter by saprobic fungi was studied in old-growth and post-harvest successional Douglas-fir forests on southeast Vancouver Island, British Columbia. This study focused on leaf litter of salal (Gaultheria shallon Pursh.), a dominant understory shrub in all stands. Salal litter is characterized by the occurrence of bleached portions attributable to fungal colonization of the litter and to the variable decomposition of recalcitrant compounds, such as lignin. Analyses of proximate chemical fractions, fungal assemblages on the bleached leaf area, and pure culture decomposition assays indicated that Marasmius sp. and Coccomyces sp. were responsible for rapid decomposition and bleaching of salal leaf litter. The bleached area accounted for 17%-22% of total area of salal leaf litter collected in immature (40-60 years old), mature (85-105 years old), and old-growth (more than 290 years old) stands, but for only 2% in regeneration (5-15 years old) stands. The reduction of bleached leaf area occupied by Marasmius sp. and Coccomyces sp. in regeneration stands could be due to the changes in microenvironmental conditions on the forest floor, in litter quality, or in food-web structure in soils. The decrease of fungi able to decay recalcitrant compounds may lead to a reduction of salal decomposition rates in clear-cut sites that would persist until canopy closure occurs.