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Katherine E Frato
The goal of this study is to identify Coffea arabica O-methyltransferase (OMT) genes involved in the biosynthesis of methoxypyrazines. High levels of 2-isopropyl-3-methoxypyrazine (IPMP) and 2-isobutyl-3-methoxypyrazine (IBMP) in coffee beans are associated with the potato taste defect (PTD). Among the 34 putative O-methyltransferase genes identified in the published genome of C. canephora, three genes are highly homologous to known hydroxypyrazine OMT genes. Genes of interest were amplified and sequenced from genomic DNA of single C...
December 7, 2018: Journal of Agricultural and Food Chemistry
Yujuan Lei, Sha Xie, Huangzhao Chen, Xueqiang Guan, Zhenwen Zhang
Although 3-alkyl-2-methoxypyrazines (MPs) are very important flavor compounds in grape and wine, the metabolic pathway of these compounds has not been fully elucidated, and only a few studies have focused on it to date. In this study, we performed in situ incorporation of the proposed precursor (l-Leu) and the key intermediate (2-amino-4-methylpentanamide; AMPA) of 3-isobutyl-2-methoxypyrazine (IBMP) biosynthesis into Cabernet Sauvignon clusters. The IBMP content and the expression levels of key related genes were monitored...
March 30, 2019: Food Chemistry
Marianne McKay, Florian F Bauer, Valeria Panzeri, Astrid Buica
The odor detection threshold (ODT) of a compound is the lowest concentration at which individuals can reliably perceive a difference between a sample and its corresponding control, with 50% performance above chance. Wine is a complex matrix, and ODTs used in studies on wine can be based on inappropriate matrices and informal sensory methodologies. Formal studies confirming ODTs in wine are relatively scarce in the literature, and are complex and expensive to carry out. In this study, the sensitivity of panelists to previously published ODTs for five compounds: Guaiacol, o -cresol and 4-ethyl phenol, 3-isobutyl-2-methoxypyrazine (IBMP), and 2,4,6-trichloroanisole (TCA) associated with off-flavor/taint issues in wine, was investigated...
October 24, 2018: Foods (Basel, Switzerland)
Trevor J Rundhaug, Greg R Geimer, Chad W Drake, Antonio Arenas Amado, A Allen Bradley, Calvin F Wolter, Larry J Weber
As part of the solution to reduce the size of the Gulf of Mexico hypoxia, the state of Iowa has created the Iowa Nutrient Reduction Strategy (INRS) to reduce total nitrogen and phosphorous loads by 45% by 2035. A major component of the strategy is implementation of conservation practices to reduce loads of non-point source pollution from agricultural lands. To identify potential locations for conservation practices in Iowa watersheds, the Agricultural Conservation Planning Framework (ACPF) is being used. In addition, the location of existing implemented practices are being identified by the Iowa Best Management Practices Mapping Project (IBMP)...
October 22, 2018: Environmental Monitoring and Assessment
Fred Luciano Neves Santos, Ana Clara Paixão Campos, Leila Denise Alves Ferreira Amorim, Edimilson Domingos Silva, Nilson Ivo Tonin Zanchin, Paola Alejandra Fiorani Celedon, Rodrigo Pimenta Del-Rei, Marco Aurélio Krieger, Yara Miranda Gomes
The existence of an imperfect reference standard presents complications when evaluating the unbiased performance of novel diagnostic techniques. This is especially true in the absence of a gold standard, as is the case in chronic Chagas disease (CD) diagnosis. To circumvent this constraint, we elected to use latent class analysis (LCA). Previously, our group demonstrated the high performance of four Trypanosoma cruzi -chimeric proteins (Molecular Biology Institute of Paraná [IBMP]-8.1, -8.2, -8.3, and -8.4) for CD diagnosis using several distinct immunoassays...
November 2018: American Journal of Tropical Medicine and Hygiene
Haixu Zhang, Pengkun Ma, Jinian Shu, Bo Yang, Jingyun Huang
Taste and odor (T&O) compounds are widespread in water environments and have attracted considerable public attention. Nowadays, the standard detections of these chemicals rely mainly on off-line methods such as GC-MS or evaluation by trained analysts' senses. In this study, we report a method for the rapid detection of T&O compounds in water by exploiting a newly invented chemi-ionization source, in combination with headspace vapor measurement at room temperature. The calibrated limits of detection (LODs) of 2-methylbutyraldehyde, methyl tert-butyl ether (MTBE), methyl methacrylate (MMA), 2-isobutyl-3-methyoxypyrazine (IBMP), and 2-isopropyl-3-methoxypyrazine (IPMP) are in the range of 3...
December 4, 2018: Analytica Chimica Acta
Delvana Mutarutwa, Luciano Navarini, Valentina Lonzarich, Dario Compagnone, Paola Pittia
No abstract text is available yet for this article.
September 2018: Journal of Mass Spectrometry: JMS
Chen Liang, Renata Ristic, Vladimir Jiranek, David W Jeffery
3-Isobutyl-2-methoxypyrazine (IBMP) is a potent odorant present in grapes and wines that is reminiscent of green capsicum. Suprathreshold concentrations can lead to obvious vegetative characters and suppress desirable fruity aroma nuances in wines, but options to manage IBMP concentrations are limited. This work investigated pre- and postfermentation addition of a putative imprinted magnetic polymer (PIMP) as a remedial treatment for elevated concentrations of IBMP in Cabernet Sauvignon grape must in comparison to nonimprinted magnetic polymer (NIMP) and to a commercially available polylactic acid (PLA) based film added postfermentation...
July 11, 2018: Journal of Agricultural and Food Chemistry
Chen Liang, David W Jeffery, Dennis K Taylor
3-Isobutyl-2-methoxypyrazine (IBMP), the most prevalent grape-derived methoxypyrazine, can contribute green bell pepper, vegetative and herbaceous aromas and flavours to wines. At elevated concentrations, this potent odorant may mask desirable fruity and floral aromas in wine and may be considered as a fault. A new remediation method for wines with elevated IBMP levels has been trialled using magnetic polymers, prepared in the same way as ordinary polymers but with the incorporation of iron oxide nanoparticles as magnetic substrates...
May 10, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Yu Wang, Lei He, Qiuhong Pan, Changqing Duan, Jun Wang
Basal defoliation, as one of the most common viticulture management practices to modify fruit zone microclimates, has been widely applied aiming at improving wine quality. Wine aroma contributes greatly to wine quality, yet the effects of basal defoliation on wine aromas show discrepancies according to previous studies. This study is a meta-analysis performed to dissect the factors related to the influence of basal defoliation on volatile compounds in wine. Timing of basal defoliation plays an important role in the concentration of varietal aromas in wine...
March 28, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Artur Campos Dália Maia, Geanne Karla Novais Santos, Eduardo Gomes Gonçalves, Daniela Maria do Amaral Ferraz Navarro, Luis Alberto Nuñez-Avellaneda
BACKGROUND: 2-Alkyl-3-methoxypyrazines (MPs) are naturally occurring aromatic compounds involved in insect chemical communication as both pheromones and allelochemicals. Although rarely characterized in floral scents, they have been identified as major constituents in headspace samples from palm inflorescences and evidence pointed towards their function as attractive cues for scent-oriented pollinators, as well as florivores. In this study, we investigated the occurrence of MPs in economically exploitable palms belonging to Acrocomia and Attalea through headspace floral scent analysis and assessed their role in the selective attraction of flower-feeding cyclocephaline scarabs (Melolonthidae, Cyclocephalini) in field bioassays conducted in Brazil and Colombia...
February 25, 2018: Pest Management Science
Jingyun Fang, Jiajian Liu, Chii Shang, Chihhao Fan
Taste- and odor-causing (T&O) compounds are a major concern in drinking water treatment plants due to their negative impacts on the safety and palatability of water supply. This study explored the degradation kinetics and radical chemistry of four often-detected T&O compounds, geosmin (GSM), 2-methylisoborneol (MIB), benzothiazole (BT), and 2-isobutyl-3-methoxypyrazine (IBMP), in the ultraviolet/chlorine (UV/chlorine) advanced oxidation process. All experiments were carried out in a 700 mL photoreactor and the process effectively degraded the investigated T&O compounds in a slightly acidic environment...
February 7, 2018: International Journal of Environmental Research and Public Health
Markus Zilker, Fritz Sörgel, Ulrike Holzgrabe
Pharmaceutical manufacturers have to study the stability of drug products before marketing according to ICH guideline Q1A(R2); data of those investigations aim to set expiry dates. The expiry date on the container of a remedy assures the physician and the patient a stability of the drug in its formulation i.e. within a specification of 95-105%. Only few studies show that shelf-lives of pharmaceutical products are often longer than expiration dates. The objective of the study presented here was determining the content of nine expired ampoules manufactured in the last century and identifying the impurity profile by means of HPLC-UV and HPLC-MS, respectively...
February 20, 2018: Journal of Pharmaceutical and Biomedical Analysis
Fred Luciano Neves Santos, Paola Alejandra Fiorani Celedon, Nilson Ivo Tonin Zanchin, Amanda Leitolis, Sandra Crestani, Leonardo Foti, Wayner Vieira de Souza, Yara de Miranda Gomes, Marco Aurélio Krieger
Diagnosing chronic Chagas disease (CD) requires antibody-antigen detection methods, which are traditionally based on enzymatic assay techniques whose performance depend on the type and quality of antigen used. Previously, 4 recombinant chimeric proteins from the Instituto de Biologia Molecular do Paraná (IBMP-8.1 to 8.4) comprising immuno-dominant regions of diverse Trypanosoma cruzi antigens showed excellent diagnostic performance in enzyme-linked immunosorbent assays. Considering that next-generation platforms offer improved CD diagnostic accuracy with different T...
October 2017: Journal of Clinical Microbiology
Fred Luciano Neves Santos, Paola Alejandra Fiorani Celedon, Nilson Ivo Tonin Zanchin, Wayner Vieira de Souza, Edimilson Domingos da Silva, Leonardo Foti, Marco Aurélio Krieger, Yara de Miranda Gomes
BACKGROUND: The performance of current serologic tests for diagnosing chronic Chagas disease (CD) is highly variable. The search for new diagnostic markers has been a constant challenge for improving accuracy and reducing the number of inconclusive results. METHODOLOGY/PRINCIPAL FINDINGS: Here, four chimeric proteins (IBMP-8.1 to -8.4) comprising immunodominant regions of different Trypanosoma cruzi antigens were tested by enzyme-linked immunosorbent assay. The proteins were used to detect specific anti-T...
March 2017: PLoS Neglected Tropical Diseases
Xavier Poitou, Cécile Thibon, Philippe Darriet
The aromatic descriptor "green", reflecting grape unripeness in French red wines, is frequently associated with the levels of 3-alkyl-2-methoxypyrazines, particularly 3-isobutyl-2-methoxypyrazine (IBMP), which has bell pepper nuances. Nevertheless, not all green aromatic expressions in red wines correlate with 3-alkyl-2-methoxypyrazine concentrations. This study considered sensory and chemical approaches using Cabernet Sauvignon wines obtained from grapes harvested at one-month intervals during the 2014 and 2015 vintages to investigate other volatile odoriferous compounds...
January 18, 2017: Journal of Agricultural and Food Chemistry
Xiuzhi Bai, Ting Zhang, Chaoyi Wang, Dongliang Zong, Haipu Li, Zhaoguang Yang
Taste and odor (T&O) problems in surface water supplies attract growing environmental and ecological concerns. In this study, 10 T&O compounds, 2-methylisoborneol (2-MIB), geosmin, β-ionone, 2-isopropyl-3-methoxypyrazine (IPMP), 2-isobutyl-3-methoxypyrazine (IBMP), 2,4,6-trichloroanisole (2,4,6-TCA), 2,3,6-trichloroanisole (2,3,6-TCA), 2,3,4-trichloroanisole (2,3,4-TCA), 2,4,6-tribromoanisole (2,4,6-TBA), and trans-2,cis-6-nonadienal (NDE) were investigated in 13 water supply reservoirs and 2 water treatment plants (WTPs) in S City of China...
January 2017: Environmental Science and Pollution Research International
Durairaj Rajesh, Subramanian Muthukumar, Ganesan Saibaba, Durairaj Siva, Mohammad Abdulkader Akbarsha, Balázs Gulyás, Parasuraman Padmanabhan, Govindaraju Archunan
Transportation of pheromones bound with carrier proteins belonging to lipocalin superfamily is known to prolong chemo-signal communication between individuals belonging to the same species. Members of lipocalin family (MLF) proteins have three structurally conserved motifs for delivery of hydrophobic molecules to the specific recognizer. However, computational analyses are critically required to validate and emphasize the sequence and structural annotation of MLF. This study focused to elucidate the evolution, structural documentation, stability and binding efficiency of estrus urinary lipocalin protein (EULP) with endogenous pheromones adopting in-silico and fluorescence study...
October 26, 2016: Scientific Reports
Andreea Botezatu, Belinda S Kemp, Gary J Pickering
Alkylmethoxypyrazines (MPs) are a class of compounds that can elicit undesirable aroma and flavor characteristics in wine, and resist remediation using traditional wine making approaches. MPs are grape-derived constituents as well as contaminants from Coccinellidae beetles present during wine processing; the latter eliciting an off-flavor referred to as 'ladybug taint'. In this study we investigated the capacity of two plastic polymers-one silicone-based, the other polylactic acid-based-applied with varying surface areas to reduce concentrations of isopropylmethoxypyrazine (IPMP), sec-butylmethoxypyrazine (SBMP) and isobutylmethoxypyrazine (IBMP) in a Merlot wine using multi-dimensional gas chromatography coupled with mass spectrometry and headspace solid phase microextraction (SPME-MDGCMS)...
September 16, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Jillian A Jastrzembski, Gavin L Sacks
Quantitation of trace-level (μg/L to ng/L) volatile compounds is routinely performed in a broad range of applications, including analyses of odorants, pesticide residues, or toxins in foodstuffs and related matrices. Conventional analyses based on gas chromatography-mass spectrometry (GC-MS) are limited by low throughput, and ambient approaches to sample introduction have typically had poor sensitivity. We prepared polydimethylsiloxane-coated stainless steel meshes for extraction and preconcentration of volatiles (Solid Phase Mesh Enhanced Sorption from Headspace, SPMESH), which could then be analyzed by Direct Analysis in Real Time (DART)-MS...
September 6, 2016: Analytical Chemistry
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