Leosvaldo Salazar Marques Velozo

Odoratin 7-O-β-D-glucopyranoside from Bowdichia virgilioides

An isoflavonoid glucoside, odoratin 7-O-β-D-glucopyranoside, was isolated from the roots of Bowdichia virgilioides and its structure was established by spectroscopic and chemical methods. In vitro tests showed that this compound inhibited both T-lymphocyte and B-lymphocyte proliferation.

Absolute Configuration of a Rare Sesquiterpene: (+)-3-Ishwarone

To determine the absolute configuration of 3-ishwarone, the experimental electronic circular dichroism (ECD), electronic dissymmetry factor (EDF), optical rotatory dispersion (ORD), vibrational circular dichroism (VCD), and vibrational dissymmetry factor (VDF) spectra of (+)-3-ishwarone are analyzed with the corresponding density functional theoretical predictions for different diastereomers. ECD and ORD spectra by themselves could not facilitate the determination of the absolute configuration of this molecule. However, the magnitude of the experimental EDF of (+)-3-ishwarone is found to match better with that predicted for the (1R,2S,4S,5R,9R,11R) diastereomer. The analyses of similarity measures between experimental and predicted spectra for VCD and VDF clearly suggested that the absolute configuration of (+)-3-ishwarone is (1R,2S,4S,5R,9R,11R).

Constituents from the roots of Bowdichia virgilioides

Abstract The isolation and 13 C-NMR data of isoflavone derivatives from Bowdichia virgilioides roots are reported.

The lignan eudesmin extracted from Piper truncatum induced vascular relaxation via activation of endothelial histamine H1 receptors.

In Brazilian folk medicine, extracts from Piper species are used to reduce blood pressure. Previously, we demonstrated the vasodilatory activity of crude extracts from leaves of Piper truncatum explaining their possible use in the treatment of hypertension in traditional medicine. In the present study, we investigated the effects of eudesmin, a lignan isolated from hexane extract of leaves from Piper truncatum, on the contractility of rat aortas and the possible mechanisms involved in its vascular action. Eudesmin induced an intense concentration-dependent relaxation of aortic rings precontracted with phenylephrine. The concentration of eudesmin necessary to reduce phenylephrine-induced aortic contraction by 50% (IC(50)) was 10.69+/-0.67 microg/ml. Eudesmin-induced vasodilation required an intact endothelium since vascular relaxation was inhibited by mechanic removal of endothelium, and by pretreatment with nitric oxide synthase inhibitor and soluble guanylate cyclase inhibitor. Relaxation induced by eudesmin was also impaired in the presence of indomethacin and diphenhydramine, a cyclooxygenase inhibitor and an antagonist of type 1 histamine receptor (H(1)), respectively. IC(50) was increased to 18.1+/-1.8 and 18.1+/-2.6 microg/ml (P<0.05; n=6) after exposure to indomethacin and diphenhydramine, respectively. Atropine (muscarinic receptor antagonist), propranolol (beta-adrenoceptor antagonist) and glibenclamide (ATP-sensitive K(+) channel blocker) did not alter the effect of eudesmin. These results indicate that eudesmin-induced vascular relaxation in rat aorta is mediated by release of nitric oxide and prostanoid through the involvement of histamine receptor present in the endothelial cells.

Biochanin A triglycoside from Andira inermis

A new isoflavonol triglycoside, biochanin A 7-O-beta-D-apiofuranosyl-(1-->5)-beta-D-apiofuranosyl-(1-->6 )-beta-D- glucopyranoside (1), was isolated from Andira inermis roots in addition to the known compounds genistein 7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside and lanceolarin.

Caracterização de derivado arilbutanoídico em folhas e raízes de Ottonia anisum Sprengel

The family Piperaceae encompasses 5 genera, Piper, Peperomia, Pothomorphe, Ottonia and Sarcorhachis, and approximately 2,000 species widely distributed in the tropical and subtropical regions of the world. Most of the Ottonia species are native to Brazil and they are used in folk medicine as diuretic, salivating, and anaesthetic. Chemical studies of non-polar fractions from leaves and roots of Ottonia anisum Sprengel lead to the isolation of an arylbutanoic metabolite, the 1-butyl-3,4-methylenedioxybezene.

3-Ishwarone, a Rare Ishwarane Sesquiterpene from Peperomia scandens Ruiz & Pavon: Structural Elucidation through a Joint Experimental and Theoretical Study

3-Ishwarone, (1), a sesquiterpene with a rare ishwarane skeleton, was isolated from Peperomia scandens Ruiz & Pavon (Piperaceae). Its structure was unambiguously determined by 1D- and 2D-NMR and infrared analyses, as well as by comparative theoretical studies which involved calculations of 13C-NMR chemical shifts, using the Density Functional Theory (DFT) with the mPW1PW91 hybrid functional and Pople’s 6-31G(d) basis set, and of vibrational frequencies, using the B3LYP hybrid functional and triple ζ Dunning’s correlation consistent basis set (cc-pVTZ), of (1) and three of its possible diastereomers, compounds 2–4.

Phytochemical Investigation of Anti-plasmodial Metabolites from Brazilian Native Piper Species

Abstract The World Health Organization estimates there are 300 and 500 million new cases of malaria worldwide, every year, mostly in Africa, Asia, South Pacific Islands and South America. New efforts to search for novel drugs for treating malaria remain important in countries like Brazil, where many endemic areas still exist. The Amazonia region is responsible for more than 97 % of the malaria cases in the country. Two Piper species were chemically investigated in order to identify new anti-plasmodial plant secondary metabolites. The crude extract and sub-fractions from leaves of Piper lucaeanum were previously assayed against a resistant strain of Plasmodium falciparum. Hydrodistillation of the leaf essential oils (EO) from Piper lucaeanum and Piper claussenianum were analyzed by GC-MS. The main constituents found from P. lucaeanum leaf oil were α-pinene (30.0 %), α-zingiberene (30.4 %), β-sesquiphelandrene (11.1 %), β-bisabolene (8.9 %), while from P. claussenianum inflorescences oil nerolidol (23.7 %) and linalool (56.5 %) were the major volatile components. The oils exhibited relevant biological activity against the resistant strain of P. falciparum. P. lucaeanum leaf EO was the most promising active sample (IC50 = 2.6 µg/mL), followed by P. claussenianum EO (IC50 = 7.9 µg/mL), the pure nerolidol (IC50= 11.1 µg/mL) and the linalool (IC50= 35.0 µg/mL). These results highlight the potential of Piper oils as a source of active metabolites in the research of new anti-maliarial compounds.

Essential Oil From Organs of Piper truncatum Vell.

Abstract Essential oils from leaves, stems, roots and inflorescences of Piper truncatum were analyzed by GC and GC/MS. The main constituents of the oils were; inflorescence oil: camphene (10.3%), germacrene D (56.0%), and an isomer of α-farnesene (10.4%); leaf oil: (Z)-3-hexenol (35.3%), β-ryophyllene (24.2%), germacrene D (11.1%) and (E)-nerolidol (10.5%); stem oil: 6(Z),8(E)-N-isobutyl-decadienamide (16.2%) and root oil: 6(Z),8(E)-N-isobutyl-decadienamide (67.6%).

Anti-inflammatory effect of diterpenes-enriched fractions from Pterodon polygalaeflorus through inhibition of macrophage migration and cytokine production

To evaluate the anti‐inflammatory potential of Pterodon polygalaeflorus hexane extract (HE) and its fractions on macrophage migration in vitro and in vivo.