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.

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.

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.

Identification of bioactive metabolites from corn silk extracts by a combination of metabolite profiling, univariate statistical analysis and chemometrics.

Corn silk has been widely used as a nutritional and medicinal supplement due to its pharmacological properties, but there is a lack of studies that correlate the extracts' chemical composition with their biological activities. Herein, we performed the large-scale chemical characterization of corn silk extracts and used chemometrics to correlate the chemical composition with the biological activities of the extracts. Twenty-two metabolites were identified by High-Performance Liquid Chromatography coupled to Mass Spectrometry (HPLC-MS), whereas twelve were identified by Gas Chromatography coupled to Mass Spectrometry (GC-MS). Chemometrics allowed us to discriminate extracts obtained in different organic solvents from in natura and commercial product samples and to pinpoint potential candidate metabolites for the antioxidant and anti-glioma activities. Two flavone glycosides (7 and 8), along with a O-methylated anthocyanidin (26) seems to be the main contributors for the biological activities of the corn silk extracts.

Combination of a multiplatform metabolite profiling approach and chemometrics as a powerful strategy to identify bioactive metabolites in Lepidium meyenii (Peruvian maca).

Lepidium meyenii is an edible plant that has been used as a nutritional supplement worldwide due to its medicinal properties. However, most of the studies have focused on the pharmacological activities of the extracts rather than their chemical composition. Herein, we used a combination of a multiplatform metabolite profiling approach and chemometrics to identify bioactive metabolites in L. meyenii. Extracts obtained with ethyl acetate and ethanol showed the promising antioxidant, anti-glioma and antibacterial activities. Sixty metabolites were identified by HPLC-MS, whereas fifteen were identified by GC-MS. Partial least squares discriminant analysis (PLS-DA), hierarchical cluster analysis (HCA), and Variable Importance in Projection (VIP) successfully discriminated extracts obtained in different organic solvents from in natura dry roots and commercial product samples of L. meyenii. Additionally, correlation analysis allowed us to pinpoint potential candidates responsible for each biological activity tested for the extracts, which could be extrapolate for other food-related species.

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.

Polyprenylated benzophenone derivatives with a novel tetracyclo[8.3.1.03,11.05,10]tetradecane core skeleton from Clusia burle-marxii exhibited cytotoxicity against GL-15 glioblastoma-derived human cell line.

Three new polyprenylated benzophenone derivatives (1-3) were identified in the hexane extract of Clusia burle-marxii trunks, through the isolation and structural elucidation of their methyl derivatives, along with two known polyprenylated benzophenone derivatives sampsonine N (4) and obdeltifolione C (5). Burlemarxiones A (1) and B (2) show an unprecedent tetracyclo[8.3.1.03,11.05,10]tetradecane core skeleton. These compounds are a pair of ß-diketones in tautomeric equilibrium, whereas isonemorosonol (3) is the respective ß-diketone pair in tautomeric equilibrium with nemorosonol. Burlemarxione A methyl derivative (1a) and sampsonine N exhibited strong in vitro cytotoxic activity against GL-15 glioblastoma-derived human cell line.

A new biphenyl and antimicrobial activity of extracts and compounds from Clusia burlemarxii.

Phytochemical investigation on Clusia burlemarxii (Clusiaceae) led to isolation and identification of nine compounds. Were isolated from leaves 3-O-α-L- rhamnopyranosylquercetin, 3-O-α-L-rhamnopyranosylkaempferol, 4-hydroxy-5,5-dimethyldihydrofuran-2-one, 2Z-δ-tocotrienoloic acid and friedelin and were isolated from trunk betulinic acid, protocatechuic acid, lyoniresinol, and a new biphenyl 2,2-dimethyl-3,5-dihydroxy-7-(4-hydroxyphenyl)chromane. The structures were determined by ¹H, ¹³C-NMR, DEPT, HMBC, HMQC, HRESIMS. The Minimal Inhibitory Concentration against Streptococcus mutans, Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Escherichia coli, Salmonella choleraesuis, Pseudomonas aeruginosa, Aspergillus niger and Cladosporium cladosporioides was also determined. Extracts and compounds showed significant activity against tested Gram-positive bacteria, none activity against tested Gram-negative bacteria and fungi.