Comparative evaluation of chemical composition and biological activities of tropical fruits consumed in Manaus, central Amazonia, Brazil.

Fruits are widely recognized as sources of biologically active metabolites, such as antioxidant compounds. In this context, fruits commonly consumed in the central Amazonia, especially in its biggest metropolis (Manaus - AM/Brazil), are attractive as potential sources of antioxidant compounds related to biological activities. Most of such fruits are still poorly studied and/or remain unknown outside the Amazon region. Therefore, this study aims to investigate nine fruits (abiu, cubiu, biribá, breadfruit, genipap, peach palm, murici, soursop, and umari) regarding their chemical composition (fixed and volatile), reducing capacity, antioxidant activity, enzyme inhibition, and cytotoxicity. Determination of small organic acids, hydroxycinnamic acids, flavan-3-ols and flavonoid aglycones was done by HPLC-MS/MS, whereas determination of volatile organic compounds (VOCs) was done by HS-SPME/GC-MS. Reducing capacity was determined by the Folin-Ciocalteu method, and antioxidant activities were evaluated by DPPH, ABTS, and H-ORACFL assays. In vitro activities regarding inhibition of enzymes were tested for α-glucosidase, lipase, and α-amylase, and anti-glycation activities were evaluated for methylglyoxal and fructose. Cytotoxicity of fruit extracts was evaluated by cell viability of human fibroblast cell line (MRC-5). A total of 16 antioxidant compounds and 139 VOCs were determined, whose profiles were unique for each studied fruit. Total phenolic contents as well as antioxidant activities found herein were similar or even higher than those reported for several traditional fruits. Some of fruit extracts were able to inhibit α-glucosidase and glycation in methylglyoxal and fructose models, whereas none of them was active for lipase and α-amylase. All of the fruit extracts showed to be non-cytotoxic to MRC-5 cell line.

Chemical, Antioxidant, and Antimicrobial Evaluation of Essential Oils and an Anatomical Study of the Aerial Parts from Baccharis Species (Asteraceae).

The aim of this study was to evaluate the chemical, antioxidant, and antimicrobial activity of the essential oils as well as the anatomy of the aerial parts from Baccharis aracatubaensis, Baccharis burchellii, and Baccharis organensis owing to the therapeutic potential of Baccharis. The volatile constituents were analyzed using GC/MS, the antioxidant activity was evaluated by oxygen radical absorbance capacity (ORACFL ) and DPPH assays, and the antimicrobial activity by a microdilution technique. Of the 56 compounds identified, only seven (ß-caryophyllene, γ-muurolene, bicyclogermacrene, ß-germacrene, spathulenol, τ-muurolol, and α-cadinol) were common in the three specimens studied. Of these, γ-muurolene was found abundantly in B. aracatubaensis, while bicyclogermacrene was abundant in B. burchellii and B. organensis. The essential oils exhibited antioxidant activity in the ORACFL (>500.0 µmol TE g-1 ) and DPPH assays. However, they did not exhibit any antimicrobial activity. Secretory ducts and flagelliform glandular trichomes were observed in the anatomical study of all the Baccharis species studied.

Antifungal activity of extracts and phenolic compounds from Deguelia duckeana

ABSTRACT Candida spp. is associated with almost 80% of all nosocomial fungal infections and is considered a major cause of blood stream infections. In humans, Cryptococcosis is a disease of the lungs caused by the fungi Cryptococcus gattii and Cryptococcus neoformans. It can be potentially fatal, especially in immune-compromised patients. In a search for antifungal drugs, Deguelia duckeana extracts were assayed against these two fungi and also against Candida albicans, which causes candidiasis. Hexane branches and CH2Cl2 root extracts as well as the substances 4-hydroxylonchocarpine, 3,5,4′-trimethoxy-4-prenylstilbene and 3′,4′-methylenedioxy-7-methoxyflavone were assayed to determine the minimal inhibitory concentration. Phytochemical study of CH2Cl2 root and hexane branch extracts from D. duckeana A.M.G. Azevedo, Fabaceae, resulted in the isolation and characterization of nine phenolic compounds: 4-hydroxyderricine, 4-hydroxylonchocarpine, 3′,4′,7-trimethoxy-flavonol, 5,4′-dihydroxy-isolonchocarpine, 4-hydroxyderricidine, derricidine, 3,5,4′-trimethoxy-stilbene, 3′,4′,7-trimethoxyflavone and yangambin. The only active extract was a CH2Cl2 root showing minimal inhibitory concentration 800 µg/ml against C. gattii, and the investigation of compounds obtained from this extract showed that 4-hydroxylonchocarpine was active against all three fungi (C. neoformans, C. gattii and C. albicans). These results suggest that D. duckeana extracts have potential therapeutic value for the treatment of pathogenic fungi.

Anti-Inflammatory and Antioxidant Properties of the Extract, Tiliroside, and Patuletin 3-O-ß-D-Glucopyranoside from Pfaffia townsendii (Amaranthaceae).

Brazilian ginseng, including Pfaffia townsendii, is used in popular medicine as a natural anti-inflammatory, tonic, analgesic, and antidiabetic agent. In this study, we investigated the chemical composition and evaluated the antioxidant and anti-inflammatory activities of the P. townsendii ethanolic extract as well as the major isolated glycoside flavonoids tiliroside and patuletin 3-O-ß-D-glucopyranoside. Chromatographic techniques and spectroscopic analysis were used for the isolation and identification of the major compounds. The antioxidant potential was determined through DPPH and ORAC-FL assays. The total phenolic content was measured using Folin-Ciocalteu reagent. The anti-inflammatory activity was determined based on a model of paw edema and carrageenan- (Cg-) induced pleurisy. We identified three phenolic acids, one carboxylic acid and two flavonoids, patuletin 3-O-ß-D-glucopyranoside, and tiliroside. The ethanol crude extracts, partitions and isolated flavonoids (4581 µmol of Trolox equivalents/g of extract in ORAC and a SC50 of approximately 31.9 µg/mL in the DPPH assay) demonstrated antioxidant activity, and the ethanolic extract as well as isolated flavonoids inhibited paw edema induced by Cg and leukocyte migration in the Cg-induced pleurisy model. The extract, tiliroside, and patuletin 3-O-ß-D-glucopyranoside obtained from P. townsendii have therapeutic potential against oxidative stress-related and inflammatory disorders.

Antiprotozoal and antioxidant alkaloids from Alternanthera littoralis.

Five alkaloids, in addition to hydroxytyrosol and uridine, were isolated from aerial parts of Alternanthera littoralis P. Beauv. Among the isolated compounds, alternamide A was an unusual tricyclic alkaloid with a bridged benzoazepine core. All isolated alkaloids have a catechol moiety, indicating a possible common biosynthetic route. Their structures were established by 1D and 2D NMR spectroscopy in combination with extensive tandem MS experiments by collisional induced dissociation (CID). The antiprotozoal activity of the isolated compounds was assayed against trypomastigote forms of Trypanosoma cruzi and amastigotes of Leishmania amazonensis. Alternamine A was the most active compound, reducing markedly the viability of both parasites. Antioxidant capacities evaluated by ORACFL assay showed that the isolated alkaloids (mainly alternamide B) contributed to the high activity recorded for the ethanolic crude extract; possibly, the catechol moiety present in all structures plays a central role in this result.