The Native Fruit Geoffroea decorticans from Arid Northern Chile: Phenolic Composition, Antioxidant Activities and In Vitro Inhibition of Pro-Inflammatory and Metabolic Syndrome-Associated Enzymes.

The native tree Geoffroea decorticans (chañar) grows in the arid lands of northern Chile. It has been used as a food plant since prehistoric times. Phenolic-enriched extracts (PEEs) of Chilean chañar fruits were assessed for their chemical composition, antioxidant properties and inhibition of pro-inflammatory and metabolic syndrome-associated enzymes. Phenolic profiles were determined by HPLC-DAD-MS/MS. The PEEs of G. decorticans showed a strong effect towards the enzymes COX-1/COX-2, with inhibition percentages ranging from inactive to 92.1% and inactive to 76.0% at 50 µg PEE/mL, respectively. The IC50 values of the PEEs towards lipoxygenase and phospholipase A2 inhibitory activity were between 43.6-96.8 and 98.9-156.0 µg PEE/mL, respectively. Samples inhibited α-glucosidase (IC50 0.8-7.3 µg PEE/mL) and lipase (9.9 to >100 µg PEE/mL). However, samples did not inhibit α-amylase. The HPLC-DAD-MS analysis of the PEEs allowed the tentative identification of 53 compounds, mainly flavonol glycosides and procyanidins. The procyanidin content of the Chilean G. decorticans pulp was positively correlated with the antioxidant activity and the inhibition of the enzyme α-glucosidase. These results indicate that the Chilean chañar fruit contains bioactive polyphenols with functional properties.

Chilean prosopis mesocarp flour: phenolic profiling and antioxidant activity.

In South America, the mesocarp flour of Prosopis species plays a prominent role as a food resource in arid areas. The aim of this work was the characterization of the phenolic antioxidants occurring in the pod mesocarp flour of Chilean Prosopis. Samples were collected in the Copiapo, Huasco and Elqui valleys from the north of Chile. The samples of P. chilensis flour exhibited a total phenolic content ranging between 0.82-2.57 g gallic acid equivalents/100 g fresh flour weight. The highest antioxidant activity, measured by the DPPH assay, was observed for samples from the Huasco valley. HPLC-MS/MS analysis allowed the tentative identification of eight anthocyanins and 13 phenolic compounds including flavonol glycosides, C-glycosyl flavones and ellagic acid derivatives. The antioxidant activity and the phenolic composition in the flour suggest that this ancient South American resource may have potential as a functional food.

Flavonoids from Lonchocarpus muehlbergianus

O extrato éter de petróleo das raízes de Lonchocarpus muehlbergianus foi submetido a sucessivas análises cromatográficas (CC, CCD e CDC preparativa) levando ao isolamento de nove flavonóides (1-9) dos quais seis são inéditos na literatura (1-6) destacando-se as quatro flavanas 2,4-dioxigenadas (1-4) que representam uma nova classe de flavonóides. As estruturas moleculares foram determinadas através da análise dos respectivos espectros de RMN 1H, RMN 13C e DEPT, RMN-2D (COSY, HETCOR e COLOC), NOE, IV, UV e EM. A análise quantitativa por CLAE, mostrou que a nova flavana 1 é o flavonóide que ocorre em maior abundância no extrato.

Flavonoids from Lonchocarpus muehlbergianus.

The light petroleum extract from the roots of Lonchocarpus muehlbergianus Hassl contained nine flavonoids, including six new ones. These are 2,4-cis-2,4,5,8-tetramethoxy-(2'',3'':6,7)-furanoflavan; 2,4-cis-4-hydroxy-2,5,8-trimethoxy-(2'',3'':6,7)-furanoflavan; 2,4-cis-2-prenyloxy-4,5,8-trimethoxy-(2'',3'':6,7)-furanoflavan; 2,4-cis-2-prenyloxy-4-hydroxy-5,8-dimethoxy-(2'',3'':6,7)-furanoflavan; 2',5',6'-trimethoxy-9-(1,1-dimethylallyoxy)-[2'',3'':3',4']-furanochalcone; 5,6-dimethoxy-(2'',3'':7,8)-furanoflavone, identified by analysis of their spectral data (UV, IR, 1H and 13C NMR, 2D-NMR, NOE and MS). The natural occurrence of 2,4-dioxygenated flavan derivatives is being reported for the first time. Quantitative analysis of the petrol extract, by using reversed-phase HPLC, showed that the most abundant flavonoid in the extract is 2,4-cis-2,4,5,8- tetramethoxy-(2'',3'':6,7)-furanoflavan.