Preparation and Characterization of a Rifampicin Coamorphous Material with Tromethamine Coformer: An Experimental-Theoretical Study.

Rifampicin (RIF) is an antibiotic used to treat tuberculosis and leprosy. Even though RIF is a market-available drug, it has a low aqueous solubility, hindering its bioavailability. Among the strategies for bioavailability improvement of poorly soluble drugs, coamorphous systems have been revealed as an alternative in the increase of the aqueous solubility of drug systems and at the same time also increasing the amorphous state stability and dissolution rate when compared with the neat drug. In this work, a new coamorphous form from RIF and tromethamine (TRIS) was synthesized by slow evaporation. Structural, electronic, and thermodynamic properties and solvation effects, as well as drug-coformer intermolecular interactions, were studied through density functional theory (DFT) calculations. Powder X-ray diffraction (PXRD) data allowed us to verify the formation of a new coamorphous. In addition, the DFT study indicates a possible intermolecular interaction by hydrogen bonds between the available amino and carbonyl groups of RIF and the hydroxyl and amino groups of TRIS. The theoretical spectra obtained are in good agreement with the experimental data, suggesting the main interactions occurring in the formation of the coamorphous system. PXRD was used to study the physical stability of the coamorphous system under accelerated ICH conditions (40 °C and 75% RH), indicating that the material remained in an amorphous state up to 180 days. The thermogravimetry result of this material showed a good thermal stability up to 153 °C, and differential scanning calorimetry showed that the glass temperature (Tg) was at 70.0 °C. Solubility studies demonstrated an increase in the solubility of RIF by 5.5-fold when compared with its crystalline counterpart. Therefore, this new material presents critical parameters that can be considered in the development of new coamorphous formulations.

Three New Polyprenylated Benzophenone Derivatives Isolated from Clusia burle-marxii.

Three new polyprenylated benzophenone derivatives named burlemarxiones G-I (1-3) were isolated from C. burle-marxii trunks (compound 1) and leaves (compounds 2 and 3), along with the known compound burlemarxione F. Burlemarxione G (1) was isolated after methylation with diazomethane and it is the keto-enol tautomeric pair of burlemarxione F. Burlemarxione H (2) derives from burlemarxiones F and G, but it has additional rings due to cyclization of the prenyl group attached to C-5 that establishes new single bonds between C-1 and C-23, as well as, between C-24 and C-29. Burlemarxione I (3) has two additional cyclizations: the first encompasses the cyclization of the former isopentenyl group into an 11,11-dimethyl-six-membered ring, whereas the second produces additional rings due to the cyclization of the prenyl group attached to C-5 that establishes new single bonds between C-1 and C-23, as well as, between C-24 and C-29. All three compounds showed moderate anti-glioma activity. These results show that C. burle-marxii is an important source of sophisticated polyprenylated benzophenone derivatives.

Metabolite Profiling of Pleurotus ostreatus Grown on Sisal Agro-Industrial Waste Supplemented with Cocoa Almond Tegument and Wheat Bran.

Pleurotus ostreatus is an edible fungus with high nutritional value that uses industrial and agricultural lignocellulosic residues as substrates for growth and reproduction. Understanding their growth metabolic dynamics on agro-industrial wastes would help to develop economically viable and eco-friendly biotechnological strategies for food production. Thus, we used UHPLC/MS/MS and GNPS as an innovative approach to investigate the chemical composition of two strains of P. ostreatus, coded as BH (Black Hirataki) and WH (White Hirataki), grown on sisal waste mixture (SW) supplemented with 20 % cocoa almond tegument (CAT) or 20 % of wheat bran (WB). Metabolite dereplication allowed the identification of 53 metabolites, which included glycerophospholipids, fatty acids, monoacylglycerols, steroids, carbohydrates, amino acids, and flavonoids. This is the first report of the identification of these compounds in P. ostreatus, except for the steroid ergosterol. Most of the metabolites described in this work possess potential biological activities, which support the nutraceutical properties of P. ostreatus. Thus, the results of this study provide essential leads to the understanding of white-rot fungi chemical plasticity aiming at developing alternative biotechnologies strategies for waste recycling.

Blood plasma metabolomics of children and adolescents with sickle cell anaemia treated with hydroxycarbamide: a new tool for uncovering biochemical alterations.

Sickle cell anaemia (SCA) is a debilitating genetic haemoglobinopathy predominantly affecting the disenfranchised strata of society in Africa and the Americas. The most common pharmacological treatment for this disease is the administration of hydroxycarbamide (HC) for which questions remain regarding its mechanism of action, efficacy and long-term toxicity specifically in paediatric individuals. A multiplatform metabolomics approach was used to assess the metabolome of plasma samples from a population of children and adolescents with SCA with and without HC treatment along with non-SCA individuals. Fifty-three metabolites were identified by ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) and 1 H nuclear magnetic resonance (NMR) with a predominance of membrane lipids, amino acids and organic acids. The partial least-squares discriminant analysis (PLS-DA) analysis allowed a clear discrimination between the different studied groups, revealing clear effects of the HC treatment in the patients' metabolome including rescue of specific metabolites to control levels. Increased creatine/creatinine levels under HC treatment suggests a possible increase in the arginine pool and increased NO synthesis, supporting existing models for HC action in SCA. The metabolomics results extend the current knowledge on the models for SCA pathophysiology including impairment of Lands' cycle and increased synthesis of sphingosine 1-phosphate. Putative novel biomarkers are suggested.

HPLC/HR-MS-Based Metabolite Profiling and Chemometrics: A Powerful Approach to Identify Bioactive Compounds from Abarema cochliacarpos.

Despite its importance as a medicinal plant, there is a lack of studies that assessed the chemical composition of A. cochliacarpos extracts. Herein, we used a metabolite profiling approach and chemometrics as a powerful strategy to correlate the chemical composition with the antioxidant activity of A. cochliacarpos extracts. Extracts obtained with ethyl acetate showed greater antioxidant activity and higher total phenolic content than extracts obtained with hexane. The chemical composition was assessed by HPLC/HR-MS and it encompassed fatty alcohols, terpenoids, phenolic derivatives, lipids, carotenoid-like compounds, alkaloids, flavonoids, polyketides, and glycerophospholipids. Chemometrics successfully differentiated not only the chemical composition of extracts in response to the nature of the extraction solvent and the botanical part used during extraction but also it allowed us to associate the chemical composition with the antioxidant activity of the extracts, which might be particularly helpful for drug discovery and development programs.

The intake of dry cashew apple fiber reduced fecal egg counts in Haemonchus contortus-infected sheep.

Helminthiasis is a common disease in which parasite resistance is frequently caused by inadequate administration of anthelmintics in small ruminant production. Since phytotherapy may be an adjuvant for parasite control, we assessed whether the ingestion of cashew apple fiber (Anacardium occidentale) would reduce Haemonchus contortus infection in Santa Inês sheep. Twenty-one male sheep with mean age of 240 ±â€¯9.7 days were dewormed, infected with 4000 L3 of H. contortus Embrapa2010 (day 0 - D0) and on D28 were divided into three equally sized experimental groups: 1) control (no treatment), 2) treated with anthelmintic (monepantel, 2.5 mg/kg PV) and 3) cashew apple fiber (0.3% BW) for 7 days of adaptation plus 28 days (D63). The animals were weighed weekly for diet adjustment and individual EPGs were performed twice a week. Corn silage was given ad libitum after each animal had eaten all the cashew apple fiber, which always occurred due to its palatable flavor. The silage, cashew apple fiber and leftovers were weighed daily and the samples were analyzed for dry matter. In cashew apple fiber, the total polyphenol contents were determined spectrophotometrically and the phenol compounds were identified by LC-MS. Cashew apple fiber contained 93.6% DM, 13.0% CP, 68.7% NDF, 47.6% FDA, 1.3% MM, 1.9% EE and 22.3% LIG. Twenty phenolic compounds were detected, among them phenolic acids and flavonoids, including glycosylated ones. The general EPG averages were statistically different among control, anthelmintic and cashew groups (3449, 14 and 2070, respectively), while the mean total weight gain did not differ (3.21, 3.20 and 1.94 kg, respectively) (p < 0.05). In relation to the control group, the anthelmintic showed efficacy of 99.6% and the cashew apple fiber 40.8%. Phenolic compounds appear to play an important role in the anthelmintic activity of cashew apple fiber. Thus, its use as an adjuvant in the control of H. contortus can be encouraged in regions where it is available at low cost, mitigating the use of veterinary drugs, reducing environmental contamination by agroindustrial residues and promoting the more sustainable production of small ruminants.

Synthesis, antibacterial and cytotoxic activities of new biflorin-based hydrazones and oximes.

Biflorin 1 is a biologically active quinone, isolated from Capraria biflora. Five new biflorin-based nitrogen derivatives were synthesized, of which two were mixtures of (E)- and (Z)- isomers: (Z)-2a, (Z)-2b, (Z)-3a, (Z)- and (E)-3b, (Z)- and (E)-3c. The antibacterial activity was investigated using the microdilution method for determining the minimum inhibitory concentration (MIC) against six bacterial strains. Tests have shown that these derivatives have potential against all bacterial strains. The cytotoxic activity was also evaluated against three strains of cancer cells, but none of the derivatives showed activity.

New Cytotoxic Bibenzyl and Other Constituents from Bauhinia ungulata L. (Fabaceae).

A new bibenzyl, 2'-hydroxy-3,5-dimethoxy-4-methylbibenzyl (1) and four known compounds identified as 2'-hydroxy-3,5-dimethoxybibenzyl (2), liquiritigenin (3), guibourtinidol (4) and fisetinidol (5) were isolated from the roots of Bauhinia ungulata L. Phytochemical investigations of the stems of B. ungulata led to the isolation of the known compounds identified as liquiritigenin (3), guibourtinidol (4), fisetinidol (5), taraxerol (6), betulinic acid (7), taraxerone (8), glutinol (9), a mixture of sitosterol (10) and stigmasterol (11), pacharin (12), naringenin (13) and eriodictyol (14). The structures of these compounds were elucidated on the basis of their spectral data (IR, MS, 1D- and 2D-NMR). The cytotoxicity of the bibenzyl 1 has been evaluated against four human cancer cell lines, showing the IC50 values of 4.3 and 6.5 µg ml-1 against pro-myelocytic leukemia (HL-60) and cervical adenocarcinoma (HEP-2) cell lines, respectively. This article also registers for the first time the 13 C-NMR data of the known bibenzyl 2.

Genome-wide identification of the GDSL-type esterase/lipase protein (GELP) gene family in Ricinus communis and its transcriptional regulation during germination and seedling establishment under different abiotic stresses.

GDSL-type esterase/lipase protein (GELP) genes are crucial in the specialized lipid metabolism, in the responses to abiotic stresses, and in the regulation of plant homeostasis. R. communis is an important oilseed crop species that can sustain growth and productivity when exposed to harsh environmental conditions. Herein, we raised the question of whether the GELP gene family could be involved in the acquisition of R. communis tolerance to abiotic stresses during seed germination and seedling establishment. Thus, we used bioinformatics and transcriptomics to characterize the R. communis GELP gene family. R. communis genome possesses 96 GELP genes that were characterized by extensive bioinformatics, including phylogenetic analysis, subcellular localization, exon-intron distribution, the analysis of regulatory cis-elements, tandem duplication, and physicochemical properties. Transcriptomics indicated that numerous RcGELP genes are readily responsive to high-temperature and salt stresses and might be potential candidates for genome editing techniques to develop abiotic stress-tolerant crops.

Flavonoids, biphenyls and xanthones from the genus Clusia: chemistry, biological activities and chemophenetics relevance.

Clusia is one of the most important genera of the Clusiaceae family, comprising up to 400 species. This review describes the identification of twenty-two flavonoids from Clusia species, which includes five flavonols (1-4 and 11), six flavones (5-10), one catechin (12), one flavanone (13), and nine biflavonoids (14-22). O- and C-glycosylation are frequently observed amongst these flavonoids. Furthermore, seven biphenyls (23-29) and nine xanthones (30-38) have been isolated from Clusia species. Biphenyls and xanthones show limited occurrence within the genus, but together with biosynthetic insights, they might offer important chemophenetics leads for the consolidation of the genus Clusia within the Clusiaceae family. Altogether, this work provides an overview of the chemistry of the genus Clusia in terms of flavonoids, biphenyls and xanthones, as well as it discusses biological activities and chemophenetics of the isolated compounds, when appropriate.

Iron toxicity, ferroptosis and microbiota in Parkinson's disease: Implications for novel targets.

Parkinson's Disease (PD) is a progressive neurodegenerative disease characterized by loss of dopaminergic neurons in substantia nigra pars compacta (SNpc). Iron (Fe)-dependent programmed cell death known as ferroptosis, plays a crucial role in the etiology and progression of PD. Since SNpc is particularly vulnerable to Fe toxicity, a central role for ferroptosis in the etiology and progression of PD is envisioned. Ferroptosis, characterized by reactive oxygen species (ROS)-dependent accumulation of lipid peroxides, is tightly regulated by a variety of intracellular metabolic processes. Moreover, the recently characterized bi-directional interactions between ferroptosis and the gut microbiota, not only provides another window into the mechanistic underpinnings of PD but could also suggest novel interventions in this devastating disease. Here, following a brief discussion of PD, we focus on how our expanding knowledge of Fe-induced ferroptosis and its interaction with the gut microbiota may contribute to the pathophysiology of PD and how this knowledge may be exploited to provide novel interventions in PD.

Castor (Ricinus communis L.) differential cell cycle and metabolism reactivation, germinability, and seedling performance under NaCl and PEG osmoticum: Stress tolerance related to genotype-preestablished superoxide dismutase activity.

Castor (Ricinus communis) is a relevant industrial oilseed feedstock for many industrial applications, being globally mainly cultivated by smallholder farmers in semiarid areas, where abiotic stresses predominate. Therefore, susceptible to generating reactive oxygen species (ROS) and subsequent oxidative stress, compromising cell metabolism upon seed imbibition and germination, seedling and crop establishment, and yield. The present study evaluated the consequences of water restriction by Polyethylene glycol (PEG) and Sodium chloride (NaCl) on cell cycle and metabolism reactivation on germinability, seedling growth, and vigor parameters in 2 commercial castor genotypes (Nordestina and Paraguaçu). PEG water restriction inhibited germination completely at -0.23 MPa or higher, presumably due to reduced oxygen availability. The restrictive effects of NaCl saline stress on germination were observed only from -0.46 MPa onwards, affecting dry mass accumulation and the production of normal seedlings. In general, superoxide dismutase (SOD) activity increased in NaCl -0.23 MPa, whereas its modulation during the onset of imbibition (24h) seemed to depend on its initial levels in dry seeds in a genotype-specific manner, therefore, resulting in the higher stress tolerance of Nordestina compared to Paraguaçu. Overall, results show that Castor germination and seedling development are more sensitive to the restrictive effects of PEG than NaCl at similar osmotic potentials, contributing to a better understanding of the responses to water restriction stresses by different Castor genotypes. Ultimately, SOD may constitute a potential marker for characterizing castor genotypes in stressful situations during germination, early seedling, and crop establishment, and a target for breeding for Castor-improved stress tolerance.

Influence of seasonality and habitat on chemical composition, cytotoxicity and antimicrobial properties of the Libidibia ferrea.

Libidibia ferrea Mart, belonging to the Fabacee family, is a medicinal plant known for its biological properties and production of phenolic compounds. Previous studies reveal the biological activity of its phenolic constituents, making it very promising for the development of new medicines. Seasonality and geographic distribution of species can modify the production of secondary metabolites in Fabaceae species in terms of the preferentially activated metabolic pathways and, consequently, interfere with the medicinal properties of these species. Studying the influence of seasonality on the production of phenolic constituents is essential to establish conditions for "cultivation," species collection, standardization, production, and safety in traditional medicine. This unprecedented study proposed to evaluate the influence of seasonal variations and habitat on the production of phenolic compounds and biological properties of the ethanolic extracts of the stem bark from L. ferrea, whose specimens were collected from the Caatinga and the Atlantic Forest, biomes of Brazil. Antimicrobial activity was determined by broth microdilution. Cytotoxicity was evaluated through a colorimetric assay using MTT. ABTS and DPPH radical reduction methods estimated antioxidant capacities. Folin-Ciocalteu and AlCl3 spectrophotometric methods quantified total phenolics and flavonoids, respectively. In turn, radial diffusion quantified tannin content. PCA score plot and HCA dendogram were obtained by multivariate analysis of 1H NMR data. The cytotoxicity against C6 glioma cells was observed only for Atlantic Forest extracts (EC50 = 0.13-0.5 mg mL-1). These extracts also showed selectivity against Gram-positive bacteria Bacillus subtilis (ATCC 6633) [MICs 500-2000 µg mL-1], B. cereus CCT 0096) [MIC = 250 µg mL-1], Staphylococcus aureus (ATCC 6538) [MICs = 250-500 µg mL-1], S. epidermidis (ATCC 12228) [62.5-1000 µg mL-1], mainly to Staphylococcus sp. Caatinga extracts showed higher production of flavonoids and antioxidants in the summer [7.36 ± 0.19 µg QE mg-1 extract; IC50ABTS = 4.86 ± 0.05 µg mL-1], spring [5.96 ± 0.10 µg QE mg-1 extract; IC50ABTS = 5.96 ± 0.08 µg mL-1 ], winter [4.89 ± 0.25 µg QE mg-1 extract; IC50ABTS = 6.72 ± 0.08 µg mL-1 ]. Regarding habitat, two discriminating compound patterns in the studied biomes were revealed by NMR. The results indicated that the Caatinga biome offers better conditions for activating the production of phenolics [336.34 ± 18.1 µgGAE mg-1 extract], tannins [328.38 ± 30.19 µgTAE mg-1 extract] in the summer and flavonoids in winter, spring, and summer. The extracts that showed the best antioxidant activities were also those from the Caatinga. In turn, extracts from the Atlantic Forest are more promising for discovering antibacterial compounds against Staphylococcus sp and cytotoxic for C6 glioma cells. These findings corroborated the traditional use of L. ferrea bark powder for treating skin wounds and suggest the cytotoxic potential of these extracts for glioblastoma cell lines.

Blood plasma and bone marrow interstitial fluid metabolomics of sickle cell disease patients with osteonecrosis: An exploratory study to dissect biochemical alterations.

Individuals with sickle cell disease (SCD) often experience numerous vaso-occlusive crisis events throughout their lives, which can progress to severe damage of several organs, including avascular necrosis, also known as osteonecrosis (ON). Osteonecrosis is one of the most devastating musculoskeletal clinical manifestations of sickle cell disease, afflicting up to 50% of the SCD patients. Herein, a NMR-based untargeted metabolomics approach was used to assess the metabolome alterations of blood plasma and bone marrow interstitial fluid (BMIF) samples of SCD patients with osteonecrosis. Furthermore, biochemical signatures associated with different osteonecrosis stages were assessed by analysing the metabolome of blood plasma and bone marrow interstitial fluid samples of SCD patients with different stages of the disease based on the Fiat and Arlet classification (FAC). Multivariate statistical analysis allowed a clear discrimination between the studied groups and it provided important insights into the different osteonecrosis stages. Citrate was pointed out as a possible biomarker to differentiate SCD patients with and without osteonecrosis. Acetate, creatinine, histidine, tyrosine, glucose, and NI5 seems to be key metabolites associated to different stages of the disease. Although this is a pioneer exploratory study, we acknowledge that fact that it is limited by the group sizes and absence of a validation cohort. Nevertheless, multivariate statistical analyses indicated that the metabolome of blood plasma and BMIF samples encompasses a complex metabolic regulation system for osteonecrosis.

Bioactive compounds from Vellozia pyrantha A.A.Conc: A metabolomics and multivariate statistical analysis approach.

The chemical composition of V. pyrantha resin (VpR) and fractions (VpFr1-7 and VpWS) were assessed by LC-MS and NMR. Twenty-eight metabolites were identified, including 16 diterpenoids, seven nor-diterpenoids, one fatty acid, one bis-diterpenoid, one steroid, one flavonoid, and one triterpenoid. The pharmacological potential of VpR, VpFr1-7, and isolated compounds was assessed by determining their antioxidant, antimicrobial, and cytotoxic activities. VpFr4 (IC50 = 205.48 ± 3.37 µg.mL-1) had the highest antioxidant activity, whereas VpFr6 (IC50 = 842.79 ± 10.23 µg.mL-1) had the lowest. The resin was only active against Staphylococcus aureus (MIC 62.5 µg.mL-1) and Salmonella choleraesius (MIC and MFC 500 µg.mL-1), but fractions were enriched with antibacterial compounds. V. pyrantha resin and fractions showed great cytotoxic activity against HCT116 (IC50 = 20.08 µg.mL-1), HepG2 (IC50 = 20.50 µg.mL-1), and B16-F10 (12.17 µg.mL-1) cell lines. Multivariate statistical analysis was used as a powerful tool to pinpoint possible metabolites responsible for the observed activities.

Solids Turn into Liquids-Liquid Eutectic Systems of Pharmaceutics to Improve Drug Solubility.

The low solubility of active pharmaceutical ingredients (APIs) is a problem in pharmaceutical development. Several methodologies can be used to improve API solubility, including the use of eutectic systems in which one of the constituents is the API. This class of compounds is commonly called Therapeutic Deep Eutectic Systems (THEDES). THEDES has been gaining attention due to their properties such as non-toxicity, biodegradability, and being non-expensive and easy to prepare. Since the knowledge of the solid liquid diagram of the mixture and the ideal eutectic point is necessary to ascertain if a mixture is a deep eutectic or just a eutectic mixture that is liquid at ambient temperature, the systems studied in this work are called Therapeutic Liquid Eutectic Systems (THELES). Therefore, the strategy proposed in this work is to improve the solubility of chlorpropamide and tolbutamide by preparing THELES. Both APIs are sulfonylurea compounds used for the treatment of type 2 diabetes mellitus and have low solubility in water. To prepare the THELES, several coformers were tested, namely, tromethamine, L(+)-arginine, L-tryptophan, citric acid, malic acid, ascorbic acid, and p-aminobenzoic acid, in molar ratios of 1:1 and 1:2. To improve viscosity, water was added in different molar ratios to all systems. THELES were characterized by mid-infrared spectroscopy (MIR), and differential scanning calorimetry. Their viscosity, solubility, and permeability were also determined. Their stability at room temperature and 40 °C was accessed by MIR. Cytocompatibility was performed by metabolic activity and cell lysis evaluation, according to ISO10993-5:2009, and compared with the crystalline APIs. THELES with TRIS were successfully synthesized for both APIs. Results showed an increased solubility without a decrease in the permeability of the APIs in the THELES when compared with the pure APIs. The THELES were also considered stable for 8 weeks at ambient temperature. The cells studied showed that the THELES were not toxic for the cell lines used.

Structural, thermal, vibrational, solubility and DFT studies of a tolbutamide co-amorphous drug delivery system for treatment of diabetes.

Among the strategies for bioavailability improvement of poorly soluble drugs, co-amorphous systems have revealed to have a significant impact in the increase of the aqueous solubility of the drug, and at the same time increasing the amorphous state stability and dissolution rate when compared with the neat drug. Tolbutamide (TBM) is an oral hypoglycemic drug largely used in the treatment of type II Mellitus diabetes. TBM is a class II drug according to the Biopharmaceutical Classification System, meaning that it has low solubility and higher permeability. The aim of this study was to synthesize a co-amorphous material of tolbutamide (TBM) with tromethamine (TRIS). Density functional theory (DFT), allowed to study the structural, electronic, and thermodynamic properties, as well as solvation effects. In same theory level, several interactions tests were performed to obtain the most thermodynamically favorable drug-coformer intermolecular interactions. The vibrational spectra (mid infrared and Raman spectroscopy) are in accordance with the theoretical studies, showing that the main molecular interactions are due to the carbonyl, sulfonyl, and amide groups of TMB and the alcohol and amine groups of TRIS. X-ray powder diffraction was used to study the physical stability in dry condition at 25 °C of the co-amorphous system, indicating that the material remained in an amorphous state up to 90 days. Differential scanning calorimetry and thermogravimetric results showed a high increase of the Tg when compared with the amorphous neat drug, from 4.3 °C to 83.7 °C, which generally translated into good physical stability. Solubility studies demonstrated an increase in the solubility of TBM by 2.5 fold when compared with its crystalline counterpart.

1H NMR and UPLC-HRMS-based metabolomic approach for evaluation of the grape maturity and maceration time of Touriga Nacional wines and their correlation with the chemical stability.

Touriga Nacional is a well-adapted Portuguese grape variety in São Francisco River Valley (northeastern Brazil). Nevertheless, it has only been indicated to short-term consumption because of the lack of chemical stability, which is attributed to low grape acidity and incomplete phenolic maturity. Therefore, we used Ultra-Performance Liquid Chromatography coupled High-resolution Mass Spectrometry, Nuclear Magnetic Resonance and chemometrics (PCA and PLS-DA) to evaluate the grape maturity and maceration time on chemical composition of wines from two harvest seasons. Moreover, we investigated how these experimental factors could affect their chemical stability. Grapes maturity showed to be the main effect. Overall, phenolic acids and short-chain organic acids were found to be at higher levels in wines produced with unripe grapes from February and shorter maceration time (p < 0.05). Proanthocyanidins and other flavonoids were increased in wines macerated for longer time using overripe grapes harvested in July. Furthermore, stable wines were made from overripe grapes, which contained more galacturonic acid.

Novel polyprenylated benzophenone derivatives from Clusia burle-marxii.

Three new caged polyprenylated benzophenone derivatives named burlemarxiones D-F (1-3) were isolated from the hexane extract of Clusia burle-marxii trunks. Burlemarxione D (1) contains the tetracyclo[8.3.1.03,11.05,10]tetradecane core skeleton also observed for burlemarxione A, its probable immediate precursor. However, two additional rings are formed to produce an unprecedented complex-caged core skeleton. These additional rings could be formed by a radical cyclization reaction of one prenyl group at C-5 with C-1 and C-33, followed by oxidative dehydrogenation (rearomatization) or by an intramolecular [4 + 2] radical cycloaddition (Diels-Alder reaction), followed by an enolization reaction (rearomatization). Burlemarxiones E and F were isolated after methylation with diazomethane that was necessary to avoid the interconversion of the pair of ß-diketones in tautomeric equilibrium. The proposed biosynthetic pathway for burlemarxiones D-F involves the condensation of either lavandulyl pyrophosphate or 2-(1-methylvinyl)-hexa-5-enyl pyrophosphate with the acylphloroglucinol derivative 6-benzoyl-5-hydroxy-5-cyclohexen-1,3-dione, followed by consecutive prenylation reactions. Therefore, Clusia burle-marxii reinforces the claim that the genus Clusia is an important source of sophisticated caged polyprenylated benzophenone derivatives.

A new isoflavone glucoside and other compounds from Poiretia bahiana C. Mueller: Chemophenetics, fragmentation pattern and biogenetic implications.

The genus Poiretia belongs to the Fabaceae (Leguminosae) family and it encompasses twelve species of flowering plants. The chemistry of this genus is scarcely investigated, although some studies have demonstrated the potential of Poiretia species to produce important bioactive compounds. Herein, we describe the phytochemical investigation of P. bahiana C. Mueller leaves. A new isoflavone glucoside named as 2',4',5'-trimethoxyisoflavone-7-O-ß-D-glucopyranoside (1), along with six known isoflavones (2-7), two rotenones (8-9), cyclitol 3-O-methyl-chiro-inositol (10), the amino acid proline (11), a mixture of sitosterol (12) and stigmasterol (13), and a mixture of the triterpenes lupeol (14) and ß-amirine (15) were obtained from P. bahiana leaves. The structures were established by extensive analysis of their spectroscopic data, which included 1H NMR, 13C NMR, DEPT, and 2D-NMR (13C1H HETCOR and 13C1H COLOC). Two isoflavones (3 and 5) and two rotenones (8-9) exhibited antifungal activity against the plant pathogenic fungus Cladosporium sphaerospermum. Furthermore, the biogenetic implications of the oxygenation pattern of the B-ring of the isoflavones, and the chemophenetics and fragmentation pattern of the isoflavones and rotenones are discussed.