Extrato de folhas de Piper scutifolium apresentou atividade antifúngica significativa contraCladosporium cladosporioides e C. sphaerospermum e seus principais componentes ativos, piperina, piperlonguminina e corcovadina foram isolados por meio de purificação biomonitorada, apresentando limites de detecção de 1 µg. Foi realizado um estudo da relação estrutura-atividade baseado na síntese de doze análogos com variações no número de insaturações, no padrão de substituição no anel aromático e no grupo amídico. As amidas sem substituintes no anel aromático e com apenas uma ligação dupla foram as mais ativas e os derivados N,N-dietil-substituídos apresentam maior dose-dependência.The antifungal leaves extract from Piper scutifolium was submitted to bioactivity-guided chromatographic separation against Cladosporium cladosporioides and C. sphaerospermum yielding piperine, piperlonguminine and corcovadine as the active principles which displayed a detection limit of 1 µg. Structure-activity relationships were investigated with the preparation of twelve analogs having differences in the number of unsaturations, aromatic ring substituents and in the amide moiety. Analogs having a single double-bond and no substituent in the aromatic ring displayed higher activity, while N,N,-diethyl analogs displayed higher dose-dependent activity. Keywords: Piper, antifungal, analogs, amides IntroductionPiper (Piperaceae) are commonly herbs, shrubs or infrequently trees with over 1000 species described so far mostly on tropical regions. 1 In addition to the high economical value of black pepper (P. nigrum) as a spice, there are several medicinal uses described for different Piper species, including anti-inflammatory, analgesic and treatment of snake-bite. 2,3 Several Piper species have been phytochemicaly investigated 4-6 and a plethora of secondary metabolites has been found including kavalactones, 7,8 lignoids, 9-11 chromenes, 12,13 terpenes, 14,15 prenylated benzoic acids 13,16,17 and also amides as the most characteristic classes of compounds. 18,19 The most prominent example of a Piper amide is piperine, the pungent principle of black pepper (P. nigrum). It was the first natural product isolated from Piper species back in 1819. Piperine and several other amides have shown a variety of biological activity, e.g., antitumoral, [20][21][22] efflux-pump inhibitor, 23-25 insecticidal 19,26-36 and antifungal activity. [37][38][39] The importance of insecticidal activity of Piper amides is considerable and thus several studies have been addressed to investigate possible structureactivity relationships. For instance, isobutylamides have shown high activity against different insects including Musca domestica, 40 Aedes aegypti 36 and A. togoi 41 and compounds bearing methylenedioxyphenyl substituents can act in some cases as synergists for other compounds by interfering with cytochrome P450-mediated detoxifications of insecticides. 34,42,43 In spite of the occurrence of several antifungal amides in plants, 37,38,44,45 the data concerning the m...

The volatile compounds present in the volatile oils and aroma from fresh flowers of Bidens segetum Martius ex Colla were characterized. The samples were collected from naturally occurring populations of the Brazilian Cerrado and from plants cultivated at the Instituto de Botânica de São Paulo (Atlantic rainforest) from its seeds. The essential oils were obtained by hydrodistillation in a Clevenger apparatus, while the aroma was extracted by headspace solid-phase microextraction (HS-SPME) and both were analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). β-Phellandrene (18-45%) and germacrene D (6-32%) were always present in the oils and aroma; however, their percentages varied. Besides these, E-β-ocimene (11.6%), myrcene (11.2%), α-pinene (7.3%), sabinene (6.7%), bicyclogermacrene (5.7%) and δ-cadinene (3.2%) appeared as major constituents of the volatile components from B. segetum flowers.

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The essential oil from the aerial parts of two cultivated subspecies from Porophyllum ruderale, Porophyllum ruderale subsp. macrocephalum (PRM) and Porophyllum ruderale subsp. ruderale (PRR) were obtained by hydrodistillation and analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). Monoterpenes were the most abundant components. The oil from PRM presented limonene (83.5%), myrcene (6.3%) and 1-undecene (5.4%) as the major compounds, while the oil from PRR contained E-β-ocimene (54.9%), limonene (25.2%) and β-pinene (10.1%) as the main components. These results suggest that the main component of the essential oil can differentiate the two P. ruderale subspecies.

The objective of this study was to find out the influence of soil nutrition on the composition of volatile oils of Porophyllum ruderale subsp. macrocephalum and Porophyllum ruderale subsp. ruderale. The seedlings were transplanted into pots containing sand as substrate. Every seven days, different Hoagland solutions were applied: Complete solution and solution lacking, respectively nitrogen, phosphorus, potassium, calcium, magnesium, sulfur and a control. The experiment was done in a randomized block with eight treatments and five replicates. For biometrics, height, leaf area and dry mass of shoots were analyzed. The average was compared by Tukey test (5%) probability. Aerial parts were collected and oil was extracted by hydrodistillation in Clevenger apparatus for 4 h. The major components of P. ruderale subsp. ruderale were trans-β-ocimene monoterpene, limonene and hydrocarbon undecene. As for the P. ruderale subsp. macrocephalum, the major component was monoterpene limonene and undecene hydrocarbon. The results of biometric analyses in this work showed that the two species have different growth. Treatments without nitrogen, phosphorus and the control had the lowest average and increased undecene content in the two subspecies. The chemical composition of volatile oils nutrition did not interfere significantly in their composition. Monoterpene limonene was the highest in macrocephalum subspecies.

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