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Phytochemical studies of the species Pavonia glazioviana were performed. Quercetin, kaempferol, acacetin, and trimethoxylated flavonoid compounds (which present biological activity) were isolated. We aimed to evaluate the in silico, in vitro, and ex vivo toxicity of flavonoid 5,7-dihydroxy-3,8,4'-trimethoxy (Pg-1) obtained from P. glazioviana through chemical structure analyses, toxicity assessment, and predictive bioactive properties, using human samples in in vitro tests. In silico analysis suggested that Pg-1 presents a good absorption index for penetrating biological membranes (for oral bioavailability), while also suggesting potential antimutagenic, anticarcinogenic, antioxidant, antineoplastic, anti-inflammatory, anti-hemorrhagic, and apoptosis agonist bioactivities. Assessment of hemolytic and genotoxic effects revealed low hemolysis rates in red blood cells with no cellular toxicity in oral mucosa cells. The reduced cytotoxic activity suggested the safety of the concentrations used (500-1000 µg/mL), and demonstrated the varied interactions of Pg-1 with the analyzed cells. The data obtained in the present study suggested potential therapeutic application, and the non-toxic profile indicated viability for future studies.

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A phytochemical study of Pavonia multiflora A. St-Hil. (Malvaceae) led to the isolation through chromatographic techniques of 10 secondary metabolites: vanillic acid (1), ferulic acid (2), p-hydroxybenzoic acid (3), p-coumaric acid (4), loliolide (5), vomifoliol (6), 4,5-dihydroblumenol A (7), 3-oxo-α-ionol (9), blumenol C (10), and taraxerol 4-methoxybenzoate (8), the latter being a novel metabolite. Their structures were identified by (1) H- and (13) C-NMR, using one- and two-dimensional techniques, and X-ray crystallography. In this work, we report the effect of compounds 5 and 8 on several photosynthetic activities in an attempt to search for new compounds as potential herbicide agents that affect photosynthesis. Both compounds inhibited the electron flow from H2 O to methyl viologen; therefore, they act as Hill reaction inhibitors. Using polarographic techniques and studies of the fluorescence of chlorophyll a, the interaction sites of these compounds were located at photosystem II.

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RESUMO No Brasil, a família Malvaceae está representada por aproximadamente 200 espécies e algumas foram descritas como gastroproteroras. Pavonia alnifolia A.St.-Hil. (Malvaceae) foi selecionada após uma abordagem quimiossistemática, considerando-se sua potencial capacidade em prevenir lesões gástricas. Assim, a atividade gastroprotetora do extrato etanólico de caules de P. alnifolia foi avaliada utilizando o modelo de indução aguda da lesão gástrica por etanol acidificado em camundongos. Além disso, foram quantificados o teor de flavonóides, pelo método de cloreto de alumínio, e de polifenóis, pelo método Folin-Ciocalteu, uma vez que a relação desses componentes com a proteção gástrica foi evidenciada. Os ensaios apontaram redução acentuada das lesões gástricas em camundongos tratados com o extrato da planta em todas as doses ensaiadas (10, 100 e 300 mg/kg). Esse efeito pode estar relacionado com a presença de polifenóis, cujo teor encontrado foi 74,3 ± 7,5 µg equivalente de pirogalol/mg do material vegetal examinado e 82,7 ± 7,1 µg equivalente de pirogalol /mg da amostra no extrato preparado por percolação e teor de flavonoides totais, que por sua vez apresentou um resultado de 17,1 ± 1,4 µg/mg de extrato. O extrato apresentou proteção da mucosa gástrica e este efeito pode estar relacionado à presença dos polifenóis e flavonóides encontrados

ABSTRACT Gastro protective activity of the Pavonia alnifolia A.St.-Hil. extract. In Brazil, the Malvaceae family is represented by at about 200 species. Some of those species are known as gastro protective ones. The Pavonia alnifolia A.St.-Hil (Malvaceae) was selected after a chemosystematic approach. The gastro preventive activity of the ethanol extract of stems Pavonia alnifolia was evaluated through the use of the Ethanol:chlroridric acid model on mice. The quantification of the total flavonoids (aluminum chloride method) and total polyphenols (Folin-Ciocalteu method) was also performed since the relation of those components with gastric protection has been previously highlighted. The tests showed a significant reduction of the ulcer formation in the mice treated with the plant extract (10, 100 and 300 mg/kg). This effect may be related to the presence of polyphenols whose content was found to be 74.3 ± 7.5 µg/mg of vegetal material and 82.7 ± 7.1 µg/mg of crude extract and flavonoids, which in turn showed a content of 17.1 ± 1.4 µg/mg dry extract

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INTRODUCTION: Pavonia xanthogloea is traditionally used as an antimicrobial and anti-tumour medicine in Southern Brazilian region. However, investigations about this species are still incipient. HYPOTHESIS TESTED: The study postulated that P. xanthologea specie present some phenolic compound and present some biological properties as anti-oxidant and cytoprotective effect against oxidative stress. MATERIALS AND METHODS: The content of eight phenolic molecules in the crude ethanolic extract of the aerial part of P. xanthogloea and its five fractions (hexane, dichloromethane, ethyl-acetate, n-butanol, and water) was determined by heterotrophic plate count method. The anti-oxidant capacity of the extract and the fractions was determined by 1,1-diphenyl-2-picryl-hydrazyl assay. The potential anti-oxidant and cytoprotective effect was also analyzed in human lymphocyte culture treated with extract/fractions at different concentrations with and without oxidative stress generated by hydrogen peroxide (H2O2) and sodium nitroprusside (SNP) exposition. RESULTS: Tiliroside was the molecule detected in all extract. Water and ethyl-acetate fractions showed the highest radical-scavenging activity. The crude extract, hexane, water, and n-butanol reversed the higher reactive oxygen specie levels generated by H2O2 and SNP to levels similar to those observed in the control group. In addition, crude extract, hexane, ethyl-acetate and n-butanol did not caused cytotoxicity, whereas water fraction was cytotoxic at higher concentration tested here (300 µg/mL). The cytotoxicity reversion caused by SNP exposition was concentration-dependent of the extract and fractions. However, dichloromethane fraction increased cell mortality in all concentrations investigated and was not able to decrease cell death in the lymphocytes exposed to SNP. CONCLUSION: The results suggest potential medicine use of this species.

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Heliopetes arsalte (Linnaeus, 1758) (Hesperiidae, Pyrginae) é uma espécie com ampla distribuição, especialmente em vegetação aberta, e suas larvas utilizam diversas espécies de Malvaceae como plantas hospedeiras. Larvas de H. arsalte foram encontradas em inflorescências de Pavonia rosa-campestris St. Hil. (Malvaceae), sendo este um novo registro de planta hospedeira desta espécie de borboleta no cerrado do Brasil central. Ilustrações de ovo, da larva e da pupa, e a ocorrência de parasitismo da larva por Braconidae (Hymenoptera) são apresentadas.

Heliopetes arsalte (Linnaeus, 1758) (Hesperiidae, Pyrginae) is a widespread skipper butterfly, commonly found in open sites. The larvae may utilize several species of Malvaceae as host plants. In this study, larvae of H. arsalte were observed on inflorescences of Pavonia rosa-campestris St. Hil. (Malvaceae), which represents a new record of host plants for this butterfly in cerrado of central Brazil. Illustrations of the immature and adult stages, as well as the occurrence of parasitism by Braconidae (Hymenoptera) are presented.

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Tigridia pavonia (L.f.) DC. is one of the important phytogenetic resources of México. This species is used as ornamental, food and medicinal purposes. Despite its ornamental and economic potential, there is little information about the genetic variability. In this study, randomly amplified polymorphic DNA (RAPD) primers of 10, 15 and 20 bases were used to assess the level of genetic variation among nine botanical varieties of Tigridia pavonia collected in three localities within State of México. The total number fragments, polymorphic fragments, percentage of polymorphism and resolving power were greater for 15 base (55, 52, 94.5 and 5, respectively) and 20 base (47, 45, 95.7 and 3.8, respectively), in comparison with those obtained from 10 base primers (44, 41, 93.1 and 3.6, respectively).Results showed the major effectiveness of 15 and 20 bases RAPD primers in the genetic differentiation of varieties as compared to 10 bases RAPD primers. The dendrograms based on un-weighted pair group method arithmetic average (UPGMA) analysis of the 10, 15, 20 and the pooled (10, 15 and 20) bases RAPD data were consistent in the clustering varieties, grouping them in two main clusters.

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The response of net photosynthesis to temperature, moisture, and light was examined in thalli of the tropical basidiomycete lichen Cora pavonia from recent lahar flows on the volcanic summit La Soufrière (Guadeloupe, French West Indies). Although thalli of C. pavonia are typically exposed to only low light intensities and isothermal temperature conditions under prevailing cloud/shroud conditions on La Soufrière, their photosynthetic response matrix reveals an unexpected breadth of response. The temperature optimum of net photosynthetic uptake in C. pavonia rises from 6°C at a photon flux area density of 25 µmol m-2 s-1 PAR to 27°C at 1000 µmol m-2 s-1 PAR, with rates of maximal net photosynthetic uptake exceeding 25 mg CO2 g-1 h-1. Net photosynthesis was optimal at thallus moisture contents of 250 to 350 percent water content by weight, declining only slightly in fully saturated thalli. These response patterns pose an apparent paradox, as on most days they will act to severely restrict net photosynthetic uptake by thalli of C. pavonia on La Soufrière. This paradox is discussed in context of those selective pressures faced by lichen thalli in later successional stages as well as those imposed by brief periods of atypical weather conditions.