Roberta Gomes Coelho

Evaluation of anti-Mycobacterium tuberculosis activity of Campomanesia adamantium (Myrtaceae)

The anti-Mycobacterium tuberculosis activity of Campomanesia adamantium fruits extracts were evaluated. Six compounds, identified as flavanones and chalcones were quantified by HPLC-DAD-UV. Promising antitubercular activity was observed with ethyl acetate extract (MIC 62.5 μg/mL) and their fractions (MIC values ranging from 39 to above 250 μg/mL). The better MIC result of 39 μg/mL was associated with two fractions that contain bigger amounts of 5,7-dihydroxy-6, 8-di-C-methylflavanone and 2’,4’-dihydroxy-3’,5’dimethyl-6’-methoxychalcone. These compounds exhibited MICs >250 and 62.5 μg/mL, respectively, while their mixtures showed values ranging from 62.5 to 7.8 μg/mL, demonstrating a synergism between them.

Determination of phenolic compounds and evaluation of antioxidant capacity of Campomanesia adamantium leaves

Five flavanones and three chalcones were isolated from Campomanesia adamantium Berg. (Myrtaceae) leaves. The contents of these compounds were determined by HPLC. The phe- nolic contents were also determined. The monitoring of the antioxidant activity was carried out by inhibition of peroxidation using the linoleic acid system and radical-scavenging (DPPH). The plants were collected from 4 distinct cities of the Mato Grosso do Sul State, Brazil. The different samples exhibited a range of 4.67-232.35 mg/g chalcones and 15.62-50.71 mg/g flavanones and phe- nolic contents of the 7.24-21.19 mg/g gallic acid. All extracts showed high antioxidant activity with a wide range of the radical-scavenging (DPPH) from 52.0 to 92.2 % and inhibition oxidation of linole- ic acid from 14.6 to 94.2%.

Gas Chromatography-Mass Spectrometry (GC-MS) and evaluation of antioxidant and antimicrobial activities of essential oil of Campomanesia adamantium (Cambess.) O. Berg (Guavira)

The essential oils from Campomanesia adamantium (Cambess.) O. Berg leaves, collected in the reproductive (flowering and fruit-bearing) and vegetative stages, were characterized by GC-MS (Gas Chromatography-Mass Spectrometry). A total of 95 compounds of the essential oils were identified. In the reproductive stage (flowering) the major constituents were monoterpenes (limonene, α-pinene and β-pinene) while during the vegetative stage the major constituents were the sesquiterpenes (bicyclogermacrene and globulol). The essential oil of the reproductive stage shows high antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans, and all show moderate activity against Escherichia coli. The essential oils were also evaluated for their radical-scavenging activity by DPPH. The chemogeographical variations of the oil composition from the four distinct localities studied all contained α-pinene, β-pinene, limonene, linalool, β-caryophyllene, germacrene D and bicyclogermacrene, however the samples from Jardim city contained neither limonene nor linalool.

A new cytotoxic naphthopyrone dimer from Paepalanthus bromelioides.

A new naphthopyrone dimer was isolated from the capitula of Paepalanthus bromelioides by chromatographic procedures. It structure was deduced from spectrometric data. On colorimetric assay for cytotoxicity the new dimer showed IC50 of 55.9 microM.

Antimicrobial Activity of the Extracts and Fractions of Hexanic Fruits of Campomanesia Species (Myrtaceae)

The antimicrobial activity of the hexanic extracts and fractions of fruits of Campomanesia pubescens pubescens (D.C) O. Berg and Campomanesia adamantium (Cambess.) O. Berg were assayed against six microorganisms. The hexanic extracts of C. pubescens and C. adamantium fruits were also investigated in their composition by gas chromatography-mass spectrometry and high-performance liquid chromatography with diode array detection. The results of this study showed the presence of 34 volatile compounds and flavonoids in the hexanic extract of C. pubescens and 33 volatile compounds and flavonoids in the hexanic extract of C. adamantium.

Gastric anti-ulcer activity of leaf fractions obtained of polar extract from Wilbrandia ebracteata in mice

Leaf fractions of Wilbrandia ebracteata were investigated for anti-ulcerogenic effects in ethanol and indomethacin-induced gastric ulcer assays in mice. Protective anti-ulcer effects were detected only in the ethanol-induced ulcer assay effects after pre-treatment with MeOH extract, MeOH chlorophyll-free, chlorophyll residue, HEX, DCM, aqueous MeOH fraction, ethyl acetate (EtOAc) and aqueous fractions. A potent anti-ulcerogenic effect was determined after pre-treatment of animals with EtOAc fraction, which was fractionated for isolation of active constituents. Seven flavonoids, 3′,4′,5,6,7,8-hexahydroxyflavonol, orientin, isoorientin, vitexin, isovitexin, luteolin, 6-methoxi-luteolin were isolated from the leaves of W. ebracteata (Cucurbitaceae) by chromatographic methods and identified by their spectral data. The data suggest that flavonoids are active anti-ulcerogenic compounds from leaves of W. ebracteata. The ability of scavenging free radicals was evaluated by DPPH reduction assay by TLC of flavonoids isolated.

Influência da variação sazonal nos teores de flavonóides e atividade antioxidante das folhas de Campomanesia adamantium (Cambess.) O. Berg, Myrtaceae

Campomanesia adamantium (Cambess.) O. Berg, Myrtaceae, is a native species. The extracts of ethyl acetate and hexane showed little variation in their chemical composition at different seasons of the year associated with the development of the plant, while the ethanol extract showed significant change in relationship to chemical composition. All ethanol extracts showed high antioxidant activity against DPPH method and from moderate to high antioxidant activity for β-carotene/linoleic acid.

Gastroprotective Effect of Serjania erecta Radlk (Sapindaceae): Involvement of Sensory Neurons, Endogenous Nonprotein Sulfhydryls, and Nitric Oxide

The present study reveals the pharmacological action of Serjania erecta Radlk. (Family Sapindaceae), an important medicinal plant species used in the Brazilian Pantanal against gastric pain. The methanolic (Me) and chloroformic (Se) extracts obtained from leaves of S. erecta were challenged by a very strong necrotizing agent in rodents, absolute ethanol. Se was also confronted with a nitric oxide synthase inhibitor (N(G)-nitro-L-arginine methyl ester), a capsaicin cation channel transient receptor potential vanilloid type 1 antagonist (ruthenium red), or a sulfhydryl-blocker (N-ethylmaleimide) to evaluate the participation of these cytoprotective factors in gastroprotection. In an in vivo experimental model, Me and Se presented several degrees of gastroprotective action without signs of acute toxicity. The best gastroprotective effect was restricted to all doses of Se. The mechanisms involving the gastroprotective action of Se are related to an augmented defense mechanism of the gastrointestinal mucosa consisting of sensory neurons, nitric oxide, and sulfhydryl groups that prevent and attenuate the ulcer process. The presence of polyisoprenoids in the Se explains the potent gastroprotective action of this medicinal species. Effective gastroprotective action and the absence of acute toxicity indicate this species may be a promising herbal drug against gastric disease.

Chemical constituents from the infusion of Zollernia ilicifolia vog. and comparison with Maytenus species

The new flavonoid glycoside kaempferol-3-O-α→ʟ-rhamnopyranosyl(1→ 2)-O-[α-ʟ-rhamnopyranosyl( 1→6)]-O-β-ᴅ-galactopyranoside-7-O-α-ʟ-rhamnopyranoside was isolated together with (S)-zierin from the leaves of Zollernia ilicifolia (Fabaceae), a medicinal plant used as analgesic and antiulcerogenic effects in Brazilian Tropical Atlantic Rain Forest. The structures were established on the basis of 1H, 13C NMR and 2D NMR (COSY, HMBC, HMQC), UV, MS and IV spectra. The infusion of Zollernia ilicifolia was qualitatively compared to the infusion of the espinheiras-santas (Maytenus aquifolium and Maytenus ilicifolia) by HPLCDAD

Chemical Composition and Antioxidant and Antimycobacterial Activities of Bromelia balansae (Bromeliaceae)

Bromelia balansae (Family Bromeliaceae) is a medicinal plant commonly used in the central region of Brazil as a cough syrup and also eaten roasted. The methanolic extract of ripe fruits was analyzed by chromatographic methods and spectrometrically. Four glycoside flavonols were isolated: kaempferol-3-O-α-L-rhamnopyranoside (1), kaempferol-3-O-α-L-rhamnopyranosyl-(1-->6)-ß-D-glucopyranoside (2), quercetin-3-O-α-L-rhamnopyranosyl-(1-->6)-ß-d-glucopyranoside (3), and kaempferol 3,7-di-O-α-L-rhamnopyranoside (4). The resazurin microtiter assay was used to measure the biological activity in vitro against Mycobacterium tuberculosis. The results showed a moderate activity of the methanolic extract with a minimal inhibitory concentration of 128 μg/mL. Antioxidant activity was evaluated as free radical scavenging capacity and inhibition of peroxidation. Free radical scavenging capacity was assessed by measuring the scavenging activity of methanolic extract and methanolic fraction on 2,2-diphenyl-1-picrylhydrazyl radical. The methanolic extract showed low values of antioxidant activities, whereas the methanolic fraction exhibited free radical scavenging activity ranging from 20.2% to 91.1%, and the inhibition of peroxidation values ranging from 5.6% to 27.5%. This is the first chemical study reported in the literature about this species.