The comprehended knowledge of the metabolic profile of the fecal matter has been recognized as an important point for understanding metabolic changes in the human systemic metabolism and it can provide precious information about host-gut microbiota interactions. However, few analytical strategies have been addressed for a broad analysis of metabolites with different chemical properties to better understand the chemical space of fecal samples. Here we report a systematic pipeline to achieve comprehensive coverage of the fecal metabolome, from high polar to nonpolar metabolites, using dog fecal samples as a proof-of-concept. This pipeline comprises a monophasic (ACN/H2O) and a biphasic extraction (methyl tert-butyl ether (MTBE)/MeOH/H2O) of the sample, followed by three liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS) methods using HILIC-amide, RP-C18 and CSH-C18 columns, and a switch polarity acquisition mode in the electrospray ion source. This approach allowed the annotation of 376 metabolites from 70 different chemical classes. The chemical space analysis by molecular networking and the pathway analysis revealed the complexity of the fecal sample and the importance of combined methods to better understand biochemical pathways. This pipeline can be used as a valuable tool to comprehend the relationship between host-gut microbiota metabolites and the influence of diet, medication, or environmental changes.

A new tetraglycosylated flavonoid derivative of kaempferol was isolated from the butanol extract of leaves of Platycyamus regnellii (Fabaceae) using high-speed countercurrent chromatography (HSCCC). The butanol extract (960.5 mg) was initially fractionated with the solvent system EtOAC-BuOH-H2O 2:8:10 (v/v/v) (elution in normal phase mode). The fractions containing the major tetraglycosylated flavonoid were further purified with the same solvent system by modifying the ratios to 3:7:10 (v/v/v) and alternating the elution to reversed phase mode. The structure of the isolated flavonoid (48.1 mg, 99.7% purity by ultra-high performance liquid chromatography with diode array detector (UHPLC-DAD)) was characterized by spectrometric and spectroscopic methods and identified as kaempferol 3-O-β-D-glucopiranosyl-(1®2)-α-L-rhamnopiranoside-(1®6)-α-L-rhamnopiranoside-7-O-α-L-rhamnopiranoside. Other minor flavonoids were also detected and tentatively identified using ultra-high performance liquid chromatography with diode array detector coupled to mass spectrometry using the electrospray ionization interface (UHPLC-DAD-ESI-MS/MS). By using the latter technique, a second tetraglycosylated flavonol with an O-methyl substituent (either rhamnetin, 3-O-methyl-quercetin or isorhamnetin) was detected, together with a triglycosylated kaempferol and diglycosylated flavonoids (either rhamnetin, 3-O-methyl-quercetin or isorhamnetin).

Three new steroidal glycoalkaloids (SGA) were isolated from green berries of Solanum pseudoquina A. St.-Hil. The extract obtained after treatment with 5% acetic acid aqueous solution was subjected to several chromatographic procedures, leading to an enriched alkaloidal fraction. The enriched alkaloidal fraction was subjected to a semi preparative high performance liquid chromatography (HPLC) leading to the isolation of three new SGA from S. pseudoquina: 3-O-(β-D-glucopyranosyl) (20S,25S)-22,26-epimino-16α-acetyl-cholesta-22(N)-ene, 3-O-(β-D-glucopyranosyl) (20R,25ξ)-23,26-epimino-16α-acetyl-cholesta-5,23(N)-dien-22-one and 3-O-(β-D-glucopyranosyl) (20S,25ξ)-23,26-epimino-16α-acetyl-cholesta-5,23(N)-dien-22-one. The structures of the new compounds were elucidated with the help of 1D and 2D nuclear magnetic resonance (NMR) and infrared spectroscopy together with high resolution electrospray ionization and atmospheric pressure chemical ionization mass spectrometry.

This study describes the isolation of a flavonoid fraction from leaves of Ocotea notata (Nees & Mart.) Mez, Lauraceae, the identification of six major compounds (an A-type proanthocyanidin trimer [3], isoquercitrin [4], reynoutrin [5], miquelianin [6], quercitrin [7], afzelin [8]) and four minor compounds (catechin [1], epicatechin [2], quercetin [9], kaempferol [10]) present in the fraction and its activity against the Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). The 50% effective concentrations values (EC50) calculated from the dose-response curve and the selectivity indices (SI) against the virus were: EC50 35.8 µg/mL and SI 5.5 to HSV-1 and EC50 23.5 µg/mL and SI 8.5 to HSV-2. The flavonoid fraction was more active against HSV-2 than HSV-1. The mechanisms of antiviral action of the flavonoid fraction against the virus were also evaluated. The percentage inhibition (PI) obtained for HSV-2 was higher than 90% in the following assays: virucidal, pre-treatment of cells, treatment of cells after viral adsorption and treatment of cells after viral penetration. For HSV-1, the flavonoid fraction had no effect in pre-treatment of cells and showed 60% of inhibition in virucidal assay.

Duas saponinas triterpênicas foram isoladas do extrato etanólico das raízes de Chiococca alba (L.) Hitch. (Rubiaceae). Suas estruturas foram elucidadas por RMN de ¹H e 13C 1D e 2D e por espectrometria de massas de alta resolução com ionização por eletronebulização como 3-O-β-D-glucopiranurosil-3-β-hidroxiolean-12,15-dien-28-oato de O-α-D-apiofuranosil (1→3)- [α-D-apiofuranosil (1→4)]-α-L-rhamnopiranosil (1→2)-α-L-arabinopiranosila (1) e 3-O-β-D-glucopiranurosil-3-β-hidroxiolean-12,15-dien-28-oato de 28-O-α-D-apiofuranosil (1→3)-α-L-rhamnopiranosil (1→2)-α-L-arabinopiranosila (2).

Two triterpene saponins were isolated from the ethanolic extract of the roots of Chiococca alba (L.) Hitch (Rubiaceae). Their structures were determined by ¹H and 13C 1D and 2D NMR and high resolution electrospray mass spectrometry as 3-O-β-D-glucopyranurosyl-3β-hydroxyolean-12,15-dien-28-oic acid 28-O-α-D-apiofuranosyl (1→3)-[α-D-apiofuranosyl (1→4)]-α-L-rhamnopyranosyl (1→2)-α-L-arabinopyranosyl ester (1) and 3-O-β-D-glucopyranurosyl-3β-hydroxyolean-12,15-dien-28-oic acid 28-O-α-D-apiofuranosyl (1→3)-α-L-rhamnopyranosyl (1→2)-α-L-arabinopyranosyl ester (2).