Compound 8-C-rhamnosyl apigenin (8CR) induced a moderate reduction in the enzymatic activity of secretory phospholipase A2 (sPLA2) from Crotalus durissus terrificus and cytosolic phospholipase A2 (cPLA2), but the compound also significantly inhibited the enzymatic activity of the enzyme cyclooxygenase. In vitro assays showed that the compound induced a slight change in the secondary structure of sPLA2 from Crotalus durissus terrificus snake venom. In vivo assays were divided into two steps. In the first step, the 8CR compound was administered by intraperitoneal injections 30 min prior to administration of sPLA2. In this condition, 8CR inhibited edema and myonecrosis induced by the sPLA2 activity of Crotalus durissus terrificus in a dose-dependent manner by decreasing interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), prostaglandin E2 (PGE2), and lipid peroxidation. This has been demonstrated by monitoring the levels of malondialdehyde (MDA) in rat paws after the course of edema induced by sPLA2. These results, for the first time, show that sPLA2 of Crotalus durissus terrificus venom induces massive muscle damage, as well as significant edema by mobilization of cyclooxygenase enzymes. Additionally, its pharmacological activity involves increased lipid peroxidation as well as TNF-α and IL-1β production. Previous administration by the peritoneal route has shown that dose-dependent 8CR significantly decreases the enzymatic activity of cyclooxygenase enzymes. This resulted in a decrease of the amount of bioactive lipids involved in inflammation; it also promoted a significant cellular protection against lipid peroxidation. In vivo experiments performed with 8CR at a concentration adjusted to 200 μg (8 mg/kg) of intraperitoneal injection 15 min after sPLA2 injection significantly reduced sPLA2 edema and the myotoxic effect induced by sPLA2 through the decrease in the enzymatic activity of cPLA2, cyclooxygenase, and a massive reduction of lipid peroxidation. These results clearly show that 8CR is a potent anti-inflammatory that inhibits cyclooxygenase-2 (COX-2), and it may modulate the enzymatic activity of sPLA2 and cPLA2. In addition, it was shown that Crotalus durissus terrificus sPLA2 increases cell oxidative stress during edema and myonecrosis, and the antioxidant properties of the polyphenolic compound may be significant in mitigating the pharmacological effect induced by sPLA2 and other snake venom toxins.

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.

A família Piperaceae é formada por 5 gêneros, Piper, Peperomia, Pothomorphe, Ottonia e Sarcorhachis, com cerca de 2000 espécies de ampla distribuição nas regiões tropicais e subtropicais do mundo. Das 23 espécies descritas para o gênero Ottonia, a maioria é nativa do Brasil. Essas plantas são popularmente utilizadas no país como diuréticas, salivantes e anestésicas. O estudo químico dos extratos apolares de folhas e de raízes de Ottonia anisum Sprengel levou ao isolamento de um componente majoritário identificado como o derivado arilbutanoídico: 1-butil-3,4-metilenodioxibeneno. 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

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%).