Insect feeding preferences on Piperaceae species observed in São Paulo city, Brazil

Piperaceae species have been placed among the basal angiosperm and are adapted to a variety of habitats including moist forests, secondary vegetation and dry high lands. The major anatomical/morphology features are of small trees, vines, and shrubs for Piper species, while the epiphytic and succulent characteristics are predominant forms among Peperomia species. Their secondary chemistry can be mostly represented by amides, phenylpropanoids/lignoids, and chromenes in addition to a phletoria of biosynthetically mixed-origin secondary compounds. Although several amides and lignans are known as insecticides, several phytophagous insects, among which some considered pests of economic importance, have been observed feeding vigorously on Piperaceae species. Herein we describe the feeding preferences of fourteen phytophagous species of Coleoptera, Lepidoptera and Hemiptera over approximately fifty Piperaceae species observed in São Paulo, SP, Brazil, in a long-term basis.

Antifungal compounds from plants

Due to the increase of the incidence of fungal infections in humans and the limitations of the available antimycotic drugs, among which the emergence of resistant strains, there is a need for the discovery of new antifungal agents. Plants, especially those used in Traditional Medicine, linked to an unmatched chemical diversity, either as pure compounds or as plant extracts, provide unlimited opportunities for the development of new antifungals. Inrecent years, compounds from different phytochemical groups have been described as having antifungal activity, including polyphenols, saponins, or peptides, among others, as well asessential oils and their constituents. After screening of ethnopharmacologically selected plants, mainly from Latin-America, followed by bio-guided isolation, our group hasdescribed the antifungal activity of different types of plant constituents, such as sesquiterpenes, triterpenes, flavonoids, lignans, fatty acids and essential oils.

Safrol e eugenol: estudo da reatividade química e uso em síntese de produtos naturais biologicamente ativos e seus derivados

The chemical reactivity of safrole, eugenol, piperonal, vanillin and derivates toward ozone, aluminium chloride, brominating agents and butyl lithium was investigated. The synthesis of naturally occuring anthraquinones, furonaphthoquinones, naphthoquinones, lignans and pterocarpans from these easily available staring materials is also discussed.

Lignanas e triterpenos do extrato citotóxico de Eriope blanchetii

This phytochemical study performed with the cytotoxic chloroformic extract of Eriope blanchetii (Benth.) Harley was the first work with this species and describes from aerial parts the isolation of two lignans of podophylotoxin type named beta-peltatin and alpha-peltatin. Besides them it was obtained four triterpenes; oleanolic acid, ursolic acid, 2alpha,3beta-dihydroxy-urs-12-en-28-olic acid, 2alpha,3beta,19alpha-trihydroxy-urs-12-en-28-olic acid, named tormentic acid and 3beta-glucosyl-sitosterol. The compounds were identified by analysis of their spectral data.

Polyphenol intake and mortality risk: a re-analysis of the PREDIMED trial

Background: Polyphenols may lower the risk of cardiovascular disease (CVD) and other chronic diseases due to their antioxidant and anti-inflammatory properties, as well as their beneficial effects on blood pressure, lipids and insulin resistance. However, no previous epidemiological studies have evaluated the relationship between the intake of total polyphenols intake and polyphenol subclasses with overall mortality. Our aim was to evaluate whether polyphenol intake is associated with all-cause mortality in subjects at high cardiovascular risk. Methods: We used data from the PREDIMED study, a 7,447-participant, parallel-group, randomized, multicenter, controlled five-year feeding trial aimed at assessing the effects of the Mediterranean Diet in primary prevention of cardiovascular disease. Polyphenol intake was calculated by matching food consumption data from repeated food frequency questionnaires (FFQ) with the Phenol-Explorer database on the polyphenol content of each reported food. Hazard ratios (HR) and 95% confidence intervals (CI) between polyphenol intake and mortality were estimated using time-dependent Cox proportional hazard models. Results: Over an average of 4.8 years of follow-up, we observed 327 deaths. After multivariate adjustment, we found a 37% relative reduction in all-cause mortality comparing the highest versus the lowest quintiles of total polyphenol intake (hazard ratio (HR) = 0.63; 95% CI 0.41 to 0.97; P for trend = 0.12). Among the polyphenol subclasses, stilbenes and lignans were significantly associated with reduced all-cause mortality (HR =0.48; 95% CI 0.25 to 0.91; P for trend = 0.04 and HR = 0.60; 95% CI 0.37 to 0.97; P for trend = 0.03, respectively), with no significant associations apparent in the rest (flavonoids or phenolic acids). Conclusions: Among high-risk subjects, those who reported a high polyphenol intake, especially of stilbenes and lignans, showed a reduced risk of overall mortality compared to those with lower intakes. These results may be useful to determine optimal polyphenol intake or specific food sources of polyphenols that may reduce the risk of all-cause mortality.

Lignanas de Strychnos guianensis (Aublet) Mart.

The present communication reports the isolation and identification of three lignans from metanolic root extracts of Strychnos guianensis (Aublet) Mart.: olivil (1), cycloolivil (2) and the unknown derivative cycloolivil carbonate (3). From hexane extracts was identified a long chain fatty acid mixture and the triterpene lupeol. The analyses were based on chromatographic and spectroscopy techniques (IR, MS, GC/MS, ¹H-NMR and 13C-NMR, 1D (BB, DEPT 135) and 2D (¹H, ¹ H-COSY, ¹H, 13C-COSY, ¹H, 13C-COSY-LR, HMQC, HMBC and NOESY) and comparison with literature data.

Flavonas, lignanas e terpeno de Piper umbellata (Piperaceae)

The phytochemical investigation of Piper umbellata leaves yielded nine compounds including one terpenoid glucoside, five flavones (vitexin 2"-O-β-glucopyranoside, apigenin 8-C-β-D-glucopyranoside,orientin 8-C-β-D-glucopyranoside,5-hydroxy-7,3',4'-trimethoxy-flavone and velutin), two lignans (sesamin e dihydrocubebin) and 4-nerolidylcathecol. Excepting 4-nerolidylcathecol, all compounds have not been described from this species yet.

Metabólitos secundários da família bromeliaceae

This review describes aspects of the Bromeliaceae family dealing the traditional applications, biological activities and distribution of secondary metabolites in distinct subfamilies. Some species are used with medicinal purposed in the treatment of respiratory, diabetes or inflammation diseases, and gastrointestinal disorders. Special emphasis on cycloartane triterpenoids and flavonoids, typical metabolites of this family, are presented. Bromeliaceae is unique amongst the monocotyledons in the frequency and variety of flavonoids with hydroxylation or methoxylation at the 6-position. Other compound classes as steroids, hidroxycinnamic acids, phenylpropane diglycerides, lignans, are presented.

Aromatic compounds from three Brazilian Lauraceae species

Phytochemical investigations on three Brazilian Lauraceae species from the Cerrado region of São Paulo State, Ocotea corymbosa (Meins) Mez., O. elegans Mez. and Persea pyrifolia Nees & Mart. ex Nees resulted in the isolation of flavonoids, an ester of the 4-O-E-caffeoylquinic acid, an aromatic sesquiterpene besides furofuran lignans. This is the first chemical study on the leaves of Ocotea elegans and O. corymbosa as well as the first report of non-volatile compounds from Persea pyrifolia.

Antioxidant activities of isolated compounds from stems of Mimosa invisa Mart. ex Colla

This work describes the phytochemical study of stems of Mimosa invisa (Mimosaceae) and the evaluation of the antioxidant potential of isolated compounds. Cromatografic techniques were employed to isolate salicifoliol, pinoresinol, quercetin, quercetin-3-O-rhamnopyranosyl, quercetin-3-O-arabinofuranosyl lupeol, β-amyrin, sitosterol, p-hydroxy coumaric acid, 4-hydroxy-3-methoxy benzaldehyde (vanillin), 4-hydroxy-3,5-dimethoxy benzaldehyde, 4-hydroxy-3-methoxy benzoic acid and 4',6,7- trimethoxy flavonol. The latter had been previously described but the spectrometric data shown indicated the structure required review. The antioxidant activity of the compounds was evaluated by the DPPH test and capability of NBT reduction by superoxide radicals. Quercetin glycosides showed lower antioxidant potential than quercetin and, salicifoliol was found to be more active than pinoresinol.

Aspectos estruturais de algumas neolignanas hidrobenzofurânicas

The neolignans are defined as dimers of allylphenol and propenylphenol between itself or crossed, whose bond does not occur by the 8-8' carbons like lignans. This review centered on stereochemical aspects of the hydrobenzofuran type, a widespread skeleton among neolignans. The chemical structures established based on spectrometric data are registered in the literature. The absolute configurations reported previously were determined by chiroptical techniques. Some chemical transformations with neolignans, performed in previous studies, afforded products which are accumulated in other vegetal species and contributed to assign the unknown stereochemistry of these natural compounds. Possible biosynthetic pathways are also proposed.

Constituintes químicos de Solanum buddleifolium Sendtn

The chemical investigation of the stem EtOH extract of S. buddleifolium resulted in the isolation of terpenoids, amides, lignans and a steroidal alkaloid. Based on HRMS, IR and ¹H and 13C NMR data analysis, the structures of the isolated compounds were identified as: 13-hydroxysolavetivone, betulinic acid, N-trans-caffeoyltyramine, N-trans-feruloyldopamine, N-trans-p-cumaroyltyramine, N-trans-feruloyltyramine, N-trans-feruloyl3'-O-methoxydopamine, alangilignoside C, isolariciresinol, polistachiol, (+)-(8R,7'S,8'S)-3α-O-(β-D-glucopiranosyl)-lioniresinol, (-)-(8S,7'R,8'R)-3α-O-(β-D-glucopiranosyl)-lioniresinol and solamargine. The occurrence of terpenoids and amides is common in Solanum, unlike lignans which are rare. The isolated lignans described in this work are reported for the first time in the genus Solanum.

Lethal weapons : novel approaches for receptor-targeted cancer cell elimination

The currently used forms of cancer therapy are associated with drug resistance and toxicity to healthy tissues. Thus, more efficient methods are needed for cancer-specific induction of growth arrest and programmed cell death, also known as apoptosis. Therapeutic forms of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) are investigated in clinical trials due to the capability of TRAIL to trigger apoptosis specifically in cancer cells by activation of cell surface death receptors. Many tumors, however, have acquired resistance to TRAIL-induced apoptosis and sensitizing drugs for combinatorial treatments are, therefore, in high demand. This study demonstrates that lignans, natural polyphenols enriched in seeds and cereal, have a remarkable sensitizing effect on TRAIL-induced cell death at non-toxic lignan concentrations. In TRAIL-resistant and androgen-dependent prostate cancer cells we observe that lignans repress receptor tyrosine kinase (RTK) activity and downregulate cell survival signaling via the Akt pathway, which leads to increased TRAIL sensitivity. A structure-activity relationship analysis reveals that the γ-butyrolactone ring of the dibenzylbutyrolactone lignans is essential for the rapidly reversible TRAIL-sensitizing activity of these compounds. Furthermore, the lignan nortrachelogenin (NTG) is identified as the most efficient of the 27 tested lignans and norlignans in sensitization of androgen-deprived prostate cancer cells to TRAIL-induced apoptosis. While this combinatorial anticancer approach may leave normal cells unharmed, several efficient cancer drugs are too toxic, insoluble or unstable to be used in systemic therapy. To enable use of such drugs and to protect normal cells from cytotoxic effects, cancer-targeted drug delivery vehicles of nanometer scale have recently been generated. The newly developed nanoparticle system that we tested in vitro for cancer cell targeting combines the efficient drug-loading capacity of mesoporous silica to the versatile particle surface functionalization of hyperbranched poly(ethylene imine), PEI. The mesoporous hybrid silica nanoparticles (MSNs) were functionalized with folic acid to promote targeted internalization by folate receptor overexpressing cancer cells. The presented results demonstrate that the developed carrier system can be employed in vitro for cancer selective delivery of adsorbed or covalently conjugated molecules and furthermore, for selective induction of apoptotic cell death in folate receptor expressing cancer cells. The tested carrier system displays potential for simultaneous delivery of several anticancer agents specifically to cancer cells also in vivo.

Identification of extractives and polysaccharides as foulants in membrane filtration of pulp and paper mill effluents

The search for new renewable materials has intensified in recent years. Pulp and paper mill process streams contain a number of potential compounds which could be used in biofuel production and as raw materials in the chemical, food and pharmaceutical industries. Prior to utilization, these compounds require separation from other compounds present in the process stream. One feasible separation technique is membrane filtration but to some extent, fouling still limits its implementation in pulp and paper mill applications. To mitigate fouling and its effects, foulants and their fouling mechanisms need to be well understood. This thesis evaluates fouling in filtration of pulp and paper mill process streams by means of polysaccharide model substance filtrations and by development of a procedure to analyze and identify potential foulants, i.e. wood extractives and carbohydrates, from fouled membranes. The model solution filtration results demonstrate that each polysaccharide has its own fouling mechanism, which also depends on the membrane characteristics. Polysaccharides may foul the membranes by adsorption and/or by gel/cake layer formation on the membrane surface. Moreover, the polysaccharides interact, which makes fouling evaluation of certain compound groups very challenging. Novel methods to identify wood extractive and polysaccharide foulants are developed in this thesis. The results show that it is possible to extract and identify wood extractives from membranes fouled in filtration of pulp and paper millstreams. The most effective solvent was found to be acetone:water (9:1 v/v) because it extracted both lipophilic extractives and lignans at high amounts from the fouled membranes and it was also non-destructive for the membrane materials. One hour of extraction was enough to extract wood extractives at high amounts for membrane samples with an area of 0.008 m2. If only qualitative knowledge of wood extractives is needed a simplified extraction procedure can be used. Adsorption was the main fouling mechanism in extractives-induced fouling and dissolved fatty and resin acids were mostly the reason for the fouling; colloidal fouling was negligible. Both process water and membrane characteristics affected extractives-induced fouling. In general, the more hydrophilic regenerated cellulose (RC) membrane fouled less that the more hydrophobic polyethersulfone (PES) and polyamide (PA) membranes independent of the process water used. Monosaccharide and uronic acid units could also be identified from the fouled synthetic polymeric membranes. It was impossible to analyze all monosaccharide units from the RC membrane because the analysis result obtained contained degraded membrane material. One of the fouling mechanisms of carbohydrates was adsorption. Carbohydrates were not potential adsorptive foulants to the sameextent as wood extractives because their amount in the fouled membranes was found to be significantly lower than the amount of wood extractives.