[Show abstract][Hide abstract] ABSTRACT: Purpose:
The aim of the present study was to analyze the lipid profile of follicular fluid from patients with endometriosis and endometrioma who underwent in vitro fertilization treatment (IVF).
The control group (n = 10) was composed of women with tubal factor or minimal male factor infertility who had positive pregnancy outcomes after IVF. The endometriosis group consisted of women with endometriosis diagnosed by videolaparoscopy (n = 10), and from the same patients, the endometriomas fluids were collected, which composed the endometrioma group (n = 10). From the follicular fluid and endometriomas, lipids were extracted by the Bligh and Dyer method, and the samples were analyzed by tandem mass spectrometry.
We observed phosphatidylglycerol phosphate, phosphatidylcholine, phosphatidylserine, and phosphatidylnositol bisphosphate in the control group. In the endometriosis group, sphingolipids and phosphatidylcholines were more abundant, while in the endometrioma group, sphingolipids and phosphatidylcholines with different m/z from the endometriosis group were found in high abundance.
This analysis demonstrated that there is a differential representation of these lipids according to their respective groups. In addition, the lipids found are involved in important mechanisms related to endometriosis progress in the ovary. Thus, the metabolomic approach for the study of lipids may be helpful in potential biomarker discovery.
Journal of Assisted Reproduction and Genetics 10/2015; DOI:10.1007/s10815-015-0592-1 · 1.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The harvesting of Brazilian mahogany (Swietenia macrophylla) is a main cause of the Brazilian Amazon deforestation and has been therefore prohibited. African mahogany (Khaya ivorensis) was then introduced for Amazon reforestation and the commercialization of such wood is legal, thus creating a challenging problem for wood certification. Herein we report that a wood chemotaxonomic method based on distinct profiles of phytochemical markers is able to promptly characterize both the native and foreign mahogany species. This challenging task has been performed via a simple, fast and unambiguous methodology using direct electrospray ionization mass spectrometry (ESI-MS) analysis of a simple methanolic extract of a tiny wood chip. Typical limonoids such as khivorin, khayanolide A and mexicanolide for African mahogany and phragmalin-type limonoids for the native Brazilian species, as well as distinct polyphenols such as catechin derivatives and cinchonain, form the characteristic phytochemical marker pools for both species. This rapid methodology could therefore be used to monitor legal and illegal mahogany tree harvesting, and hence to control Amazon deforestation. It could also be applied to create a wood certification program for African and Brazilian mahogany trees, as well as for wood certification in general.
[Show abstract][Hide abstract] ABSTRACT: Herein, we report the synthesis and mass spectrometry studies of several N-alkylbenzenesulfonamides structurally related to sulfanilic acid. The compounds were synthesized using a modified Schotten-Baumann reaction coupled with Meisenheimer arylation. Sequential mass spectrometry by negative mode electrospray ionization (ESI(-)-MS/MS) showed the formation of sulfoxylate anion (m/z 65) observed in the mass spectrum of p-chloro-N-alkylbenzenesulfonamides. Investigation of the unexpected loss of two water molecules, as observed by electron ionization mass spectrometry (EI-MS) analysis of p-(N-alkyl)lactam sulfonamides, led to the proposal of corresponding fragmentation pathways. These compounds showed loss of neutral iminosulfane dioxide molecule (M-79) with formation of ions observed at m/z 344 and 377. These ions were formed by rearrangement on ESI(+)-MS/MS analysis. Some of the molecules showed antagonistic activity against Kv3.1 voltage-gated potassium channels.
[Show abstract][Hide abstract] ABSTRACT: The antioxidant capacities of avocado, pineapple, banana, papaya, passion fruit, watermelon and melon's different parts (pulp, seed, raw peel and dried peels) were evaluated using DPPH and FRAP assays. Levels of total phenolic compounds and flavonoids were measured. Quantitation of organic acids (citric, malic and tartaric) and phenolic compounds was also performed by UPLC-ESI(-)-MS. Avocado dried peel presented the highest total phenolic compounds (1252.31±165.62mgGAE100g-1 DW), the highest antioxidant capacities by the FRAP assay (441.83±67.86μmolFeSO4 g-1 DW) and the lowest IC50 value (18.22±1.45μg·mL-1), followed by passion fruit seed (49.71±2.17μg·mL-1). Melon raw peel presented the highest total flavonoids (204.28±21.05mgEQ100g-1 DW). Citric, malic and tartaric acids as well as catechin hydrate, epicatechingallate, epicatechin, epigallocatechin, and epigallocatechin gallate were found in the methanol fruit extracts by UPLC-ESI-(-)-MS.
[Show abstract][Hide abstract] ABSTRACT: A joint experimental and theoretical investigation on the mechanism of the Petasis Borono-Mannich reaction is described. Using the charge-tag strategy for mass spectrometry ion monitoring in solution, unprecedented key intermediates were intercepted and characterized. A key intermediate was also isolated from the reaction solution and its structure could be deduced from single crystal X-ray diffraction. A mechanism further consolidated by DFT calculations that reconciles the present and all available data on this important multicomponent reaction is presented.
[Show abstract][Hide abstract] ABSTRACT: A task-specific ionic liquid constituted by a Bronsted acid (1-(3-sulfopropyl)-3-methyl-imidazolium hydrogen sulfate) as the cation, namely MSI, and by [PW12O40]3- as the triply charged counter-anion, namely PW (a heteropolyacid derivative), was used as an efficient catalyst for the condensation reaction between aldehydes and o-phenylenediamines.
[Show abstract][Hide abstract] ABSTRACT: In this study, the aim was to determine the complete sequence of the Copaifera langsdorffii trypsin inhibitor (CTI)-1 using 2-dimensional (2D)-PAGE, matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF), and quadrupole time-of-flight (QTOF) spectrometry. Spots A (CTI-1) and F (CTI-2) were submitted to enzymatic digestions with trypsin, SV8, and clostripain. The accurate mass of the peptide obtained from each digest was determined by mass spectrometry (MS) using MALDI-TOF. The most abundant peptides were purified and sequenced in a liquid chromatograph connected to an electrospray ionization-QTOF MS. When the purified trypsin inhibitor was submitted to 2D electrophoresis, different spots were observed, suggesting that the protein is composed of 2 subunits with microheterogeneity. Isoelectric points of 8.0, 8.5, and 9.0 were determined for the 11 kDa subunit and of 4.7, 4.6, and 4.3 for the 9 kDa subunit. The primary structure of CTI-1, determined from the mass of the peptide of the enzymatic digestions and the sequence obtained by MS, indicated 180 shared amino acid residues and a high degree of similarity with other Kunitz (KTI)-type inhibitors. The peptide also contained an Arg residue at the reactive site position. Its 3-dimensional structure revealed that this is because the structural discrepancies do not affect the canonical conformation of the reactive loop of the peptide. Results demonstrate that a detailed investigation of the structural particularities of CTI-1 could provide a better understanding of the mechanism of action of these proteins, as well as clarify its biologic function in the seeds. CTI-1 belongs to the KTI family and is composed of 2 polypeptide chains and only 1 disulfide bridge.
Journal of biomolecular techniques: JBT 07/2015; 26(3). DOI:10.7171/jbt.15-2603-002
[Show abstract][Hide abstract] ABSTRACT: Biodiesel quality is negatively affected by oxidation, which occurs primarily during the storage and distribution steps. Therefore, the use of suitable analytical methods to assess the oxidation of this biofuel is a fundamental requirement. A direct ambient ionization mass spectrometric technique (EASI-MS) was tested as a screening method to evaluate the oxidative quality of biodiesel during its shelf life. Using EASI-MS, the relative abundance of the hydroperoxide ion of m/z 349 was monitored during the induction period (IP) in soybean and a blend of soybean/beef-tallow (70/30) biodiesel samples. The peroxide value obtained by AOCS Cd 8b-90 was used as a standard method to evaluate the EASI-MS data by comparison. The results showed that the peroxide value and EASI-MS data were highly correlated during the IP for both samples (r > 0.98). Relative abundances of the ion of m/z 349 below 72 % was also found to characterize biodiesel in an initial oxidation stage, whereas abundances exceeding 72 % indicated biodiesel samples nearing the end of their stability. EASI-MS was therefore found to provide a simple and effective analytical protocol to evaluate the oxidative quality of biodiesel during the IP.
[Show abstract][Hide abstract] ABSTRACT: A fast, sensitive and selective ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method that is able to quantify geochemical biomarkers in sediment is described. A pool of ten sterols, which can be used as biomarkers of autochthonous (cholesterol, cholestanol, brassicasterol, ergosterol), allochthonous (stigmasterol, β-sitosterol, campesterol and stigmastanol) and anthropogenic (coprostanol and epicoprostanol) organic matter (OM) and three triterpenols, lupeol and α- and β-amyrin, were chosen as the analytes. The method showed excellent analytical parameters, and compared with the traditional GC-MS methods that are commonly applied for the analysis of sterols, this method requires no sample clean-up or derivatization and presents improved values for the LOD and LOQ. UHPLC can separate the diastereoisomers, epicoprostanol, coprostanol and cholestanol, and the isomers, lupeol, α- and β-amyrin. The method was successfully applied for the quantification of the biomarkers, and thus, it was applied to assess the OM sources and the impacts of anthropogenic activities in sediments from different environments, such as Antarctica and other Brazilian systems (Continental Shelf, São Sebastião Channel and Santos Estuary). Unique profiles of the biomarkers were observed for the contrasting environments, and β-amyrin and cholesterol were more predominant in the Santos Estuary and Antarctica samples, respectively. The sterol ratios indicated a higher level of sewage contamination in the Santos Estuary.
[Show abstract][Hide abstract] ABSTRACT: Herein we describe a new protocol that allows direct mass spectrometry imaging (IMS) of agar cultures. A simple sample dehydration leads to a thin solid agar, which enables the direct use of spray-based ambient mass spectrometry techniques. To demonstrate its applicability, metal scavengers siderophores were imaged directly from agar culture of S. wadayamensis and well resolved and intense images were obtained using both desorption electrospray ionization (DESI) and easy ambient sonic-spray ionization (EASI) with well-defined selective spatial distributions for the free and the metal-bound molecules, providing clues for their roles in cellular metabolism.
[Show abstract][Hide abstract] ABSTRACT: A metal-organic framework, Zn-[2-methylimidazolate] frameworks (ZIF-8), was used as adsorbent material to remove different concentrations of oxytetracycline (OTC) antibiotic in a fixed-bed column. The OTC was studied at concentrations of 10, 25 and 40 mg L-1. At 40 mg L-1, the breakthrough point was reached after approximately 10 minutes, while at 10 and 25 mg L-1 this point was reached in about 30 minutes. The highest removal rate of 60% for the 10 mg L-1 concentration was reached after 200 minutes. The highest adsorption capacity (28.3 mg g-1) was attained for 25 mg L-1 of OTC. After the adsorption process, a band shift was observed in the UV-Vis spectrum of the eluate. Additional studies were carried out to determine the cause of this band shift, involving a mass spectrometry (MS) analysis of the supernatant liquid during the process. This investigation revealed that the main route of adsorption consisted of the coordination of OTC with the metallic zinc centers of ZIF-8. The materials were characterized by thermal analysis (TA), scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and infrared spectroscopy (IR) before and after adsorption, confirming the presence of OTC in the ZIF-8 and the latter’s structural stability after the adsorption process.
PLoS ONE 06/2015; 10(6):e0128436. DOI:10.1371/journal.pone.0128436 · 3.23 Impact Factor