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ACS Central Science Jun 2024A subset of nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) are encoded in their biosynthetic gene clusters (BGCs) with enzymes annotated as...
A subset of nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) are encoded in their biosynthetic gene clusters (BGCs) with enzymes annotated as lantibiotic dehydratases. The functions of these putative lantibiotic dehydratases remain unknown. Here, we characterize an NRPS-PKS BGC with a putative lantibiotic dehydratase from the bacterium (). Heterologous expression revealed several metabolites produced by the BGC, and the omission of selected biosynthetic enzymes revealed the biosynthetic pathway toward these compounds. The final product is a bisarginyl ureidopeptide with an enone electrophile. The putative lantibiotic dehydratase catalyzes peptide bond formation to a Thr that extends the peptide scaffold opposite to the NRPS and PKS biosynthetic direction. The condensation domain of the NRPS SnaA catalyzes the formation of a ureido group, and bioinformatics analysis revealed a distinct active site signature EHHXXHDG of ureido-generating condensation (C) domains. This work demonstrates that the annotated lantibiotic dehydratase serves as a separate amide bond-forming machinery in addition to the NRPS, and that the lantibiotic dehydratase enzyme family possesses diverse catalytic activities in the biosynthesis of both ribosomal and nonribosomal natural products.
PubMed: 38947204
DOI: 10.1021/acscentsci.4c00044 -
Research Square Jun 2024The consumption of alcohol and caffeine affects the lives of billions of individuals worldwide. Although recent evidence indicates that caffeine impairs the reinforcing...
The consumption of alcohol and caffeine affects the lives of billions of individuals worldwide. Although recent evidence indicates that caffeine impairs the reinforcing properties of alcohol, a characterization of its effects on alcohol-stimulated mesolimbic dopamine (DA) function was lacking. Acting as the pro-drug of salsolinol, alcohol excites DA neurons in the posterior ventral tegmental area (pVTA) and increases DA release in the nucleus accumbens shell (AcbSh). Here we show that caffeine, via antagonistic activity on A2A adenosine receptors (A2AR), prevents alcohol-dependent activation of mesolimbic DA function as assessed, in-vivo, by brain microdialysis of AcbSh DA and, in-vitro, by electrophysiological recordings of pVTA DA neuronal firing. Accordingly, while the A1R antagonist DPCPX fails to prevent the effects of alcohol on DA function, both caffeine and the A2AR antagonist SCH 58261 prevent alcohol-dependent pVTA generation of salsolinol and increase in AcbSh DA in-vivo, as well as alcohol-dependent excitation of pVTA DA neurons in-vitro. However, caffeine also prevents direct salsolinol- and morphine-stimulated DA function, suggesting that it can exert these inhibitory effects also independently from affecting alcohol-induced salsolinol formation or bioavailability. Finally, untargeted metabolomics of the pVTA showcases that caffeine antagonizes alcohol-mediated effects on molecules (e.g. phosphatidylcholines, fatty amides, carnitines) involved in lipid signaling and energy metabolism, which could represent an additional salsolinol-independent mechanism of caffeine in impairing alcohol-mediated stimulation of mesolimbic DA transmission. In conclusion, the outcomes of this study strengthen the potential of caffeine, as well as of A2AR antagonists, for future development of preventive/therapeutic strategies for alcohol use disorder.
PubMed: 38946995
DOI: 10.21203/rs.3.rs-4289552/v1 -
Chemical & Pharmaceutical Bulletin 2024Alkene dipeptide isosteres (ADIs) are promising surrogates of peptide bonds that enhance the bioactive peptide resistance to enzymatic hydrolysis in medicinal chemistry....
Alkene dipeptide isosteres (ADIs) are promising surrogates of peptide bonds that enhance the bioactive peptide resistance to enzymatic hydrolysis in medicinal chemistry. In this study, we investigated the substitution effects of an ADI on the energy barrier of cis-trans isomerization in the acetyl proline methyl ester (Ac-Pro-OMe) model. The (E)-alkene-type proline analog, which favors a cis-amide conformation, exhibits a lower rotational barrier than native Ac-Pro-OMe. A van't Hoff analysis suggests that the energy barrier is primarily reduced by enthalpic repulsion. It was concluded that although carbon-carbon double bonds and pyrrolidine rings individually increase the rigidity of the incorporation site, their combination can provide structural flexibility and disrupt bioactive conformations. This work provides new insights into ADI-based drug design.
Topics: Dipeptides; Alkenes; Proline; Molecular Structure; Thermodynamics; Rotation
PubMed: 38945948
DOI: 10.1248/cpb.c24-00254 -
Yakugaku Zasshi : Journal of the... 2024Venetoclax (VEN) is used in patients with acute myeloid leukemia (AML) and is primarily metabolized by CYP3A4, a major drug-metabolizing enzyme. Patients with AML...
Venetoclax (VEN) is used in patients with acute myeloid leukemia (AML) and is primarily metabolized by CYP3A4, a major drug-metabolizing enzyme. Patients with AML simultaneously administered VEN and CYP3A4 inhibitors require a more appropriate management of drug-drug interactions (DDIs). Here, we report two cases of patients with AML (54-year-old man and 22-year-old woman) administrated VEN and CYP3A4 inhibitors, such as posaconazole, cyclosporine, or danazol. In the first case, we evaluated the appropriateness of timing for adjusting VEN dosage subsequent to the cessation of posaconazole. Consequently, modifying the VEN dosage in conjunction with the cessation of Posaconazole simultaneously may result in elevated plasma VEN levels. In the second case, plasma VEN concentrations were markedly elevated when co-administered with several CYP3A4 inhibitors. Additionally, in vitro assays were conducted for reverse translational studies to analyze CYP3A4 inhibition. CYP3A4 inhibition by combinatorial administration of cyclosporine A and danazol was demonstrated in vitro, which potentially explains the increasing plasma VEN concentrations observed in clinical settings. Although the acquisition of therapeutic effects is a major priority for patients, frequent therapeutic drug monitoring and dosage adjustments considering DDIs would be important factors in chemotherapy.
Topics: Humans; Sulfonamides; Leukemia, Myeloid, Acute; Cytochrome P-450 CYP3A Inhibitors; Drug Interactions; Male; Young Adult; Middle Aged; Bridged Bicyclo Compounds, Heterocyclic; Female; Drug Monitoring; Cytochrome P-450 CYP3A; Cyclosporine; Triazoles; Antineoplastic Agents
PubMed: 38945852
DOI: 10.1248/yakushi.24-00018 -
Yakugaku Zasshi : Journal of the... 2024An overwhelming surge of information regarding preparedness for postvaccination side effects had caused widespread confusion approximately since April 2021, when the...
An overwhelming surge of information regarding preparedness for postvaccination side effects had caused widespread confusion approximately since April 2021, when the coronavirus disease 2019 (COVID-19) vaccination had started for the general population in Japan. Notably, this resulted in a remarkably increased shortage of OTC acetaminophen formulations. The aim of this study was to elucidate the actual responses of the public in such an environment, how individuals acquired and understood information related to the management of postvaccination side effects, and how they obtained and used antipyretic analgesics before and after COVID-19 vaccination. We conducted a web-based survey in January 2022, targeting 400 individuals aged ≥20 years, who had received two COVID-19 vaccine doses, and excluded qualified professionals such as physicians and pharmacists. The results revealed that 67% of the respondents had obtained antipyretic analgesics in anticipation of adverse effects after vaccination, whereas 38% had taken these medicines before and/or after the second vaccination. Possible misappropriation of medicines from others, preventive administration, and lack of dosage and administration confirmation are the problems identified in medication acquisition and usage. Additionally, avoidance of antipyretic analgesics based on information without scientific evidence was observed. This study revealed no small amount of inappropriate use of medicines in situations, such as the COVID-19 pandemic, where there is an "infodemic" of mixed-quality information. Pharmacists, as experts in medication, should play a crucial role in promoting appropriate medication usage by consistently staying updated with the latest scientific evidence and proactively supporting OTC drug selection and counseling medication.
Topics: Humans; Antipyretics; Pharmacists; COVID-19 Vaccines; Male; Female; Middle Aged; Adult; Acetaminophen; Japan; Surveys and Questionnaires; Professional Role; Vaccination; Aged; Young Adult; Nonprescription Drugs; COVID-19
PubMed: 38945850
DOI: 10.1248/yakushi.23-00183 -
Food Research International (Ottawa,... Aug 2024Because of its peculiar flavor, chili oil is widely used in all kinds of food and is welcomed by people. Chili pepper is an important raw material affecting its quality,...
Because of its peculiar flavor, chili oil is widely used in all kinds of food and is welcomed by people. Chili pepper is an important raw material affecting its quality, and commercial chili oil needs to meet various production needs, so it needs to be made with different chili peppers. However, the current compounding method mainly relies on the experience of professionals and lacks the basis of objective numerical analysis. In this study, the chroma and capsaicinoids of different chili oils were analyzed, and then the volatile components were determined by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-ion migration spectrometer (GC-IMS) and electronic nose (E-nose). The results showed that Zidantou chili oil had the highest L*, b*, and color intensity (ΔE) (52.76 ± 0.52, 88.72 ± 0.89, and 118.84 ± 1.14), but the color was tended to be greenyellow. Xinyidai chili oil had the highest a* (65.04 ± 0.2). But its b* and L* were relatively low (76.17 ± 0.29 and 45.41 ± 0.16), and the oil was dark red. For capsaicinoids, Xiaomila chili oil had the highest content of capsaicinoids was 2.68 ± 0.07 g/kg, Tianjiao chili oil had the lowest content of capsaicinoids was 0.0044 ± 0.0044 g/kg. Besides, 96 and 54 volatile flavor substances were identified by GC-MS and GC-IMS respectively. And the main volatile flavor substances of chili oil were aldehydes, alcohols, ketones, and esters. A total of 11 key flavor compounds were screened by the relative odor activity value (ROAV). Moguijiao chili oil and Zidantou chili oil had a prominent grass aroma because of hexanal, while Shizhuhong chili oil, Denglongjiao chili oil, Erjingtiao chili oil, and Zhoujiao chili oil had a prominent floral aroma because of 2, 3-butanediol. Chili oils could be well divided into 3 groups by the partial least squares discriminant analysis (PLS-DA). According to the above results, the 10 kinds of chili oil had their own characteristics in color, capsaicinoids and flavor. Based on quantitative physicochemical indicators and flavor substances, the theoretical basis for the compounding of chili oil could be provided to meet the production demand more scientifically and accurately.
Topics: Volatile Organic Compounds; Capsicum; Gas Chromatography-Mass Spectrometry; Taste; Plant Oils; Electronic Nose; Capsaicin; Flavoring Agents; Color; Odorants
PubMed: 38945630
DOI: 10.1016/j.foodres.2024.114657 -
Food Research International (Ottawa,... Aug 2024Iron deficiency is widespread throughout the world, supplementing sufficient iron or improving the bioavailability of iron is the fundamental strategy to solve the...
Iron deficiency is widespread throughout the world, supplementing sufficient iron or improving the bioavailability of iron is the fundamental strategy to solve the problem of iron scarcity. Herein, we explored a new form of iron supplement, iron chelates of silver carp scales (SCSCP-Fe) were prepared from collagen peptide of silver carp scales (SCSCP) and FeCl·4HO, the effects of external environment and simulated gastrointestinal digestive environment on the stability of SCSCP-Fe and the structural changes of peptide iron chelates during digestion were investigated. The results of in vitro iron absorption promotion showed that the iron bioavailability of SCSCP-Fe was higher than that of FeSO. Two potential high iron chelating peptides DTSGGYDEY (DY) and LQGSNEIEIR (LR) were screened and synthesized from the SCSCP sequence by molecular dynamics and LC-MS/MS techniques. The FTIR results displayed that the binding sites of DY and LR for Fe were the carboxyl group, the amino group, and the nitrogen atom on the amide group on the peptide. ITC results indicated that the chelation reactions of DY and LR with Fe were mainly dominated by electrostatic interactions, forming chelates in stoichiometric ratios of 1:2 and 1:1, respectively. Both DY and LR had a certain ability to promote iron absorption. The transport of DY-Fe chelate may be a combination of the three pathways: PepT1 vector pathway, cell bypass, and endocytosis, while LR-Fe chelate was dominated by bivalent metal ion transporters. This study is expected to provide theoretical reference and technical support for the high-value utilization of silver carp scales and the development of novel iron supplements.
Topics: Carps; Animals; Iron Chelating Agents; Collagen; Digestion; Iron; Animal Scales; Biological Availability; Peptides; Intestinal Absorption; Humans; Fish Proteins; Ferrous Compounds; Tandem Mass Spectrometry
PubMed: 38945620
DOI: 10.1016/j.foodres.2024.114612 -
Food Research International (Ottawa,... Aug 2024Lipids from cow milk fat globule membranes (MFGMs) and extracellular vesicles (EVs) are considered beneficial for neurodevelopment, cognitive maintenance and human...
Lipids from cow milk fat globule membranes (MFGMs) and extracellular vesicles (EVs) are considered beneficial for neurodevelopment, cognitive maintenance and human health in general. Nevertheless, it is largely unknown whether intake of infant formulas and medical nutrition products rich in these particles promote accretion of specific lipids and whether this affects metabolic homeostasis. To address this, we carried out a 16-week dietary intervention study where mice were supplemented with a MFGM/EV-rich concentrate, a control diet supplemented with a whey protein concentrate and devoid of milk lipids, or regular chow. Assessment of commonly used markers of metabolic health, including body weight, glucose intolerance and liver microanatomy, demonstrated no differences across the dietary regimes. In contrast, in-depth lipidomic analysis revealed accretion of milk-derived very long odd-chain sphingomyelins and ceramides in blood plasma and multiple tissues of mice fed the MFGM/EV diet. Furthermore, lipidomic flux analysis uncovered that mice fed the MFGM/EV diet have increased lipid metabolic turnover at the whole-body level. These findings help fill a long-lasting knowledge gap between the intake of MFGM/EV-containing foods and the health-promoting effects of their lipid constituents. In addition, the findings suggest that dietary sphingomyelins or ceramide-breakdown products with very long-chains can be used as structural components of cellular membranes, lipoprotein particles and signaling molecules that modulate metabolic homeostasis and health.
Topics: Animals; Sphingolipids; Extracellular Vesicles; Mice; Glycolipids; Lipid Metabolism; Lipid Droplets; Glycoproteins; Lipidomics; Mice, Inbred C57BL; Male; Sphingomyelins; Ceramides; Diet; Liver; Dietary Supplements
PubMed: 38945615
DOI: 10.1016/j.foodres.2024.114601 -
Food Research International (Ottawa,... Aug 2024Haff disease typically develops after eating contaminated marine or freshwater species, especially fish. Despite still having an unknown etiology, recent reports have...
Investigating the etiology of Haff disease: Optimization and validation of a sensitive LC-MS/MS method for palytoxins analysis in directly associated freshwater and marine food samples from Brazil.
Haff disease typically develops after eating contaminated marine or freshwater species, especially fish. Despite still having an unknown etiology, recent reports have suggested its possible correlation with palytoxins. Therefore, the present work aimed to optimize and perform a validation of a sensitive method using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for the analysis of palytoxin and some of its analogs, with the main purpose of investigating their presence in marine and freshwater food samples associated with Haff disease in Brazil. The method optimization was performed using a central composite rotatable design and fish samples fortified with the palytoxin standard. Then, the optimized method was validated for different food matrices, including freshwater and marine fish, mollusks, and crustaceans. The sample preparation involved a solid-liquid extraction using methanol and water, solid-phase extraction using Strata-X cartridges, and on-column palytoxin oxidation. The detection of the main oxidized fragments (amino and amide aldehydes) was achieved by LC-MS/MS with electrospray ionization in positive mode, using a C18 column, as well as acetonitrile and water as mobile phases, both acidified with 0.1 % of formic acid. After optimization and validation, the etiological investigation involved the analysis of 16 Brazilian Haff disease-related food samples (in natura and leftover meals) from 2022. The method was demonstrated to be appropriate for quantitative analysis of freshwater and marine species. So far, it has proven to be one of the most sensitive methods related to palytoxin detection (LOD 10 μg/kg), being able to work in a range that includes the provisional ingestion limit (30 μg/kg). Regarding the Haff disease-related samples analysis, there is a strong indication of palytoxin contamination since the amino aldehyde (common fragment for all palytoxins) was detected in 15 of the 16 samples. Selected results were confirmed using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS).
Topics: Tandem Mass Spectrometry; Brazil; Acrylamides; Animals; Cnidarian Venoms; Chromatography, Liquid; Seafood; Fresh Water; Food Contamination; Fishes; Reproducibility of Results; Solid Phase Extraction; Limit of Detection; Liquid Chromatography-Mass Spectrometry; Polyether Toxins
PubMed: 38945605
DOI: 10.1016/j.foodres.2024.114585 -
Food Research International (Ottawa,... Aug 2024Chinese steamed bread (CSB) is an important staple of the Chinese people, and its flavor profile is mostly affected by wheat varieties among others. This study selected...
Chinese steamed bread (CSB) is an important staple of the Chinese people, and its flavor profile is mostly affected by wheat varieties among others. This study selected wheat flour made from three different wheat varieties and investigated their contribution to the CSB flavor profile in terms of metabolism. Thirteen aroma-active compounds identified by GC-O were determined as the main contributors to the different aroma profiles of three CSBs. 350 sensory trait-related metabolites were obtained from five key modules via weighted gene co-expression network analysis. It was found that the sensory characteristics of CSBs made of different wheat flour were significantly different. The higher abundance of lipids in Yongliang No.4 (YL04) wheat flour was converted to large number of fatty acids in fermented dough, which led to the bitterness of CSB. Besides, the abundance in organic acids and fatty acids contributed to the sour, milky, wetness and roughness attributes of YL04-CSB. More fatty amides and flavonoids in Jiangsu Red Durum wheat flour contributed to the fermented and winey attributes of CSB. Carbohydrates with higher abundance in Canadian wheat flour was involved in sugar-amine reaction and glucose conversion, which enhanced the sweetness of CSB. In addition, fatty acids, organic acids, amino acids, and glucose were crucial metabolites which can further formed into various characteristic compounds such as hexanal, hexanol, 2,3-butanediol, acetoin, and 2,3-butanedione and thus contributed to the winey, fresh sweet, and green aroma properties. This study is conductive to better understand the evolution of the compounds that affect the quality and aroma of CSBs.
Topics: Bread; China; Fatty Acids; Fermentation; Flour; Odorants; Steam; Taste; Triticum; Volatile Organic Compounds
PubMed: 38945592
DOI: 10.1016/j.foodres.2024.114661