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Sausage is susceptible to oxidative changes in lipids and microbial spoilage due to the presence of water, fat, protein, and vitamins. Bee pollen (BP) as a source of potential antioxidants and antibacterial compounds can effectively prevent lipid peroxidation and microbial spoilage in meat products. The aim of the present study was to investigate the antibacterial and antioxidant activities of BP and the effects of nano/microparticles of bee pollen extract (n/m BP) at a concentration of 125 and 250 mg/100 g meat on the oxidative stability and microbial growth of high‐fat sausage during 30 days of storage at 4°C. The formation of BP particles in the nano/micro range was confirmed by scanning electron microscopy. High concentrations of total phenolic compounds (28.26 ± 0.10 mg GAE/g BP) with antioxidant activity (EC50 = 5.4 ± 0.07 mg/mL) were detected in BP. Based on the microdilution assay, the minimum inhibitory concentration of n/m BP for all test bacteria was 1000 (μg/mL) and the minimum bactericidal concentration of n/m BP was 2000 (μg/mL) for Staphylococcus aureus and Bacillus cereus and 4000 (μg/mL) for Escherichia coli and Pseudomonas aeruginosa. The n/m BP treatment (250 mg/100 g meat) showed a higher pH value (p <.05) and lower TBARS values (p <.05) than the ascorbic acid treatment (100 mg/100 g meat) and the control during the storage period. The microbial analysis showed that the addition of n/m BP led to a significant decrease (p <.05) in the total bacterial count, coliforms, S. aureus, and fungal population compared to the other samples. The results show that the addition of n/m BP (125 mg/100 g) can improve the texture, taste, and overall acceptability of the sausage compared to the control sample. In conclusion, this study suggests that BP can replace synthetic antioxidants in high‐fat sausages at the nano/microparticle level. [ABSTRACT FROM AUTHOR]

Objective: During recent years, evidence-based practice as a way to support higher standards of care was emphasized by health care policymakers. Sexual dysfunction (SD) is a common problem that affects the quality of life in individuals. Today, the use of Ginkgo biloba extract (GBE) for treating SD has been considered, so this study was performed to evaluate the current evidence for the efficacy and safety of ginkgo in treating SD. Materials and Methods: In this review study, electronic databases of PubMed, Scopus, Cochrane, Google Scholar, Web of science and Persian databases such as SID and Magiran were searched up to March 2020, to identify all the studies reporting the effect of GBE for effectiveness on sexual function and its safety. The search was performed using the keywords of Ginkgo, Ginkgo biloba, Complementary and alternative medicine, women sexual dysfunction, and male sexual dysfunction. The quality of included studies was assessed using the Oxford Center for Evidence Based Medicine checklist. Results: Among 156 articles found in the initial search, 5 randomized controlled trials (475 participants) were selected for this study. After a meticulous review, we found that G. biloba can have positive effects on the sexual function of postmenopausal women, while evidence shows that it has no effect on the sexual function of antidepressants users. Headaches and gastrointestinal disturbance were among the adverse events mentioned in several trials. Conclusion: We concluded that G. biloba has limited positive effects on sexual function and more studies are needed to confirm these findings. [ABSTRACT FROM AUTHOR]

The Gram-negative bacterium Sphingomonas wittichii RW1 is notable for its ability to metabolize a variety of aromatic hydrocarbons. Not surprisingly, the S. wittichii genome contains a number of putative aromatic hydrocarbon-degrading gene clusters. One of these includes an enzyme of unknown function, Swit_4259, which belongs to the acetoacetate decarboxylase-like superfamily (ADCSF). Here, it is reported that Swit_4259 is a small (28.8 kDa) tetrameric ADCSF enzyme that, unlike the prototypical members of the superfamily, does not have acetoacetate decarboxylase activity. Structural characterization shows that the tertiary structure of Swit_4259 is nearly identical to that of the true decarboxylases, but there are important differences in the fine structure of the Swit_4259 active site that lead to a divergence in function. In addition, it is shown that while it is a poor substrate, Swit_4259 can catalyze the hydration of 2-oxo-hex-3-enedioate to yield 2-oxo-4-hydroxyhexanedioate. It is also demonstrated that Swit_4259 has pyruvate aldolase-dehydratase activity, a feature that is common to all of the family V ADCSF enzymes studied to date. The enzymatic activity, together with the genomic context, suggests that Swit_4259 may be a hydratase with a role in the metabolism of an as-yet-unknown hydrocarbon. These data have implications for engineering bioremediation pathways to degrade specific pollutants, as well as structure-function relationships within the ADCSF in general. [ABSTRACT FROM AUTHOR]

There are many reports of the anti-inflammatory, anti-cancer, and anti-atherosclerotic activities of conjugated linolenic acids (cLNA). They constitute a small percentage of fatty acids in the typical human diet, although up to 80% of the fatty acids in certain fruits such as pomegranate. In the course of studying a bacterial fatty acid dioxygenase ( Nostoc linoleate 10 S -DOX, an ancient relative of mammalian cyclooxygenases), we detected strong inhibitory activity in a commercial sample of linoleic acid. We identified two cLNA isomers, β -eleostearic (9 E ,11 E ,13 E -18:3) and β -calendic acid (8 E ,10 E ,12 E -18:3), as responsible for that striking inhibition with a Ki of ~ 49 nM and ~ 125 nM, respectively, the most potent among eight cLNA tested. We also examined the effects of all eight cLNA on the activity of COX-1 and COX-2. Jacaric acid (8 Z ,10 E ,12 Z -18:3) and its 12 E isomer, 8 Z ,10 E ,12 E -18:3, strongly inhibit the activity of COX-1 with a Ki of ~ 1.7 and ~ 1.1 μM, respectively. By contrast, COX-2 was ≤ 30% inhibited at 10 μM concentrations of the cLNA. Identifying the activities of the naturally occurring fatty acids is of interest in terms of understanding their interaction with the enzymes, and for explaining the mechanistic basis of their biological effects. The study also highlights the potential presence of inhibitory fatty acids in commercial lipids prepared from natural sources. Analysis of seven commercial samples of linoleic acid by HPLC and UV spectroscopy is illustrated as supplementary data. [ABSTRACT FROM AUTHOR]

The marls and argillaceous limestones of the Early Cretaceous Kazhdumi, Late Cretaceous Gurpi and Paleogene Pabdeh formations are considered as potential source rock candidates in this area. The present study characterizes hydrocarbon potential, type of organic matter and thermal maturity of these three formations in the Iranian sector of the Persian Gulf. Also, 1D basin modeling was used to analyse the burial history and timing of hydrocarbon generation in these formations. A total of 179 cutting samples from 25 wells were evaluated through Rock–Eval pyrolysis and organic petrography. Average total organic carbon (TOC) content for the samples of the Kazhdumi, Gurpi and Pabdeh formations that were analyzed for the current study is 1.2, 0.9 and 1 wt.%, respectively. All three formations show lower TOC contents in central part relative to eastern and western parts of the study area. Rock–Eval pyrolysis and organic petrography show that the organic matter in all three formations is mainly composed of Type II and mixed Type II–III kerogen. This study shows that the Kazhdumi, Gurpi and Pabdeh formations in Iranian offshore areas are not as rich as onshore areas, and specifically in the Dezful Embayment, in terms of organic matter quantity and quality. Thermal history modeling indicates that constant heat flow values in the range of 64–73 mW/m 2 gives the best fit between measured and calculated vitrinite reflectance and bottom hole temperature. The Rock–Eval T max , vitrinite reflectance and the generated models suggested that in the eastern parts of the study area, the Kazhdumi Formation is at the last stage of oil generation and the Gurpi and Pabdeh formations are within the main oil generation window. Hydrocarbon generation began in the Early Eocene, Middle Eocene and Early Miocene in the Kazhdumi, Gurpi and Pabdeh formations, respectively. In the western parts of the Persian Gulf, the Kazhdumi Formation is within the main oil window with hydrocarbon generation took place during the Oligocene and the Gurpi and Pabdeh formations are early mature and immature, respectively. All three formations are thermally immature in the central part of the Persian Gulf. The Kazhdumi Formation shows positive correlation with the crude oils of the Cretaceous and Tertiary reservoirs taken from the northwestern Persian Gulf. The Pabdeh and Gurpi formations show no correlation with crude oils produced in the northwestern and southeastern Persian Gulf. [ABSTRACT FROM AUTHOR]

The marls and argillaceous limestones of the Cretaceous Kazhdumi Formation, Ahmadi Member of the Sarvak Formation and Gurpi Formation are considered to be important source rock candidates in the Persian Gulf. To evaluate their source rock characteristics, 265 cutting samples of these rock units from 20 fields in offshore Iran were analyzed using Rock-Eval pyrolysis, organic petrography, stable carbon isotope composition and biomarker analysis. 1D basin modeling was also applied to analyze the burial and thermal history of these source rock candidates. Based on the results, the Kazhdumi and Gurpi formations, which have fair source rock potential, and the Ahmadi Member, which has fair to good source rock characteristics, were deposited in a marine reducing environment with marine organic matter as the main input. Different maturity indicators showed that the Ahmadi Member and Kazhdumi Formation are thermally immature to mature and the Gurpi Formation is immature to early mature in the study area. The results of the modeling suggested that the Kazhdumi Formation and Ahmadi Member in the southeastern parts of the study area are within the main oil window and that the Gurpi Formation has just begun to generate hydrocarbons. All three formations are thermally immature in the eastern parts. In the western parts of the Persian Gulf, the Kazhdumi Formation is early mature and the other formations are immature. The biomarker and stable carbon isotope parameters of these rock units were compared with 20 crude oil samples in the southeastern Persian Gulf. Based on the hierarchical cluster analysis (HCA), principal component analysis (PCA) and carbon isotope composition, the studied crude oils were divided into two groups: Group-I oils from Cretaceous reservoirs were probably derived from Cretaceous source rocks, while Group-II oils from Jurassic and Cretaceous reservoirs with Jurassic rocks as the expected source rocks. The performed oil–source rock correlation shows a positive correlation between the Group-I oils and the Ahmadi Member. [ABSTRACT FROM AUTHOR]

True catalases efficiently breakdown hydrogen peroxide, whereas the catalase-related enzyme allene oxide synthase (cAOS) is completely unreactive and instead metabolizes a fatty acid hydroperoxide. In cAOS a Thr residue adjacent to the distal His restrains reaction with H 2 O 2 (Tosha et al. (2006) J. Biol. Chem. 281:12610; De Luna et al. (2013) J. Phys. Chem. B 117: 14635) and its mutation to the consensus Val of true catalases permits the interaction. Here we investigated the effects of the reciprocal experiment in which the Val74 of human catalase is mutated to Thr, Ser, Met, Pro, or Ala. The Val74Thr substitution decreased catalatic activity by 3.5-fold and peroxidatic activity by 3-fold. Substitution with Ser had similar negative effects (5- and 3-fold decreases). Met decreased catalatic activity 2-fold and eliminated peroxidatic activity altogether, whereas the Val74Ala substitution was well tolerated. (The Val74Pro protein lacked heme). We conclude that the conserved Val74 of true catalases helps optimize catalysis. There are rare substitutions of Val74 with Ala, Met, or Pro, but not with Ser of Thr, possibly due their hydrogen bonding affecting the conformation of His75, the essential distal heme residue for activity in catalases. [ABSTRACT FROM AUTHOR]

7,8-Dihydro-D-neopterin 2',3'-cyclic phosphate (H2N-cP) is the first intermediate in biosynthesis of the pterin portion of tetrahydromethanopterin (H4MPT), a C1 carrier coenzyme first identified in the methanogenic archaea. This intermediate is produced from GTP by MptA (MJ0775 gene product), a new class of GTP cyclohydrolase I [Grochowski, L. L., Xu, H., Leung, K., and White, R. H. (2007) Biochemistry 46, 6658-66671. Here we report the identification of a cyclic phosphodiesterase that hydrolyzes the cyclic phosphate of H2N-cP and converts it to a mixture of 7,8-dihydro-D-neopterin 2'-monophosphate and 7, 8-dthydro-D-neoptertn 3'-monophosphate. The enzyme from Methanocaldococcus jannachii is designated MptB (MJ0837 gene product) to indicate that it catalyzes the second step of the biosynthesis of methanopterin. MptB is a member of the HD domain superfamily of enzymes, which require divalent metals for activity. Direct metal analysis of the recombinant enzyme demonstrated that MptB contained 1.0 mol of zinc and 0.8 mol of iron per protomer. MptB requires Fe2+ for activity, the same as observed for MptA. Thus the first two enzymes involved in H4MPT biosynthesis in the archaea are Fe2+ dependent. [ABSTRACT FROM AUTHOR]

N-Acyl-phosphatidylethanolamine phospholipase D (NAPEPLD) (EC 3.1.4.4) catalyzes the final step in the biosynthesis of N-acyl-ethanolamides. Reduced NAPE-PLD expression and activity may contribute to obesity and inflammation, but a lack of effective NAPE-PLD inhibitors has been a major obstacle to elucidating the role of NAPE-PLD and N-acyl-ethanolamide biosynthesis in these processes. The endogenous bile acid lithocholic acid (LCA) inhibits NAPE-PLD activity (with an IC50 of 68 μM), but LCA is also a highly potent ligand for TGR5 (EC50 0.52 μM). Recently, the first selective small-molecule inhibitor of NAPE-PLD, ARN19874, has been reported (having an IC50 of 34 μM). To identify more potent inhibitors of NAPE-PLD, here we used a quenched fluorescent NAPE analog, PED-A1, as a substrate for recombinant mouse Nape-pld to screen a panel of bile acids and a library of experimental compounds (the Spectrum Collection). Muricholic acids and several other bile acids inhibited Nape-pld with potency similar to that of LCA. We identified 14 potent Nape-pld inhibitors in the Spectrum Collection, with the two most potent (IC50=~2μM) being symmetrically substituted dichlorophenes, i.e. hexachlorophene and bithionol. Structure-activity relationship assays using additional substituted dichlorophenes identified key moieties needed for Nape-pld inhibition. Both hexachlorophene and bithionol exhibited significant selectivity for Nape-pld compared with nontarget lipase activities such as Streptomyces chromofuscus PLD or serum lipase. Both also effectively inhibited NAPE-PLD activity in cultured HEK293 cells.Weconclude that symmetrically substituted dichlorophenes potently inhibit NAPE-PLD in cultured cells and have significant selectivity for NAPE-PLD versus other tissue-associated lipases. [ABSTRACT FROM AUTHOR]

The riboflavin kinase in Methanocaldococcus jannaschii has been identified as the product of the MJ0056 gene. Recombinant expression of the MJ0056 gene in Escherichia coli led to a large increase in the amount of flavin mononucleotide (FMN) in the E. coli cell extract. The unexpected features of the purified recombinant enzyme were its use of CTP as the phosphoryl donor and the absence of a requirement for added metal ion to catalyze the formation of FMN. Identification of this riboflavin kinase fills another gap in the archaeal flavin biosynthetic pathway. Some divalent metals were found to be potent inhibitors of the reaction. The enzyme represents a unique CTP-dependent family of kinases. [ABSTRACT FROM AUTHOR]

In the course of exploring the scope of catalase-related hemoprotein reactivity toward fatty acid hydroperoxides, we detected a novel candidate in the cyanobacterium Nostoc punctiforme PCC 73102. The immediate neighboring upstream gene, annotated as "cyclooxygenase-2," appeared to be a potential fatty acid heme dioxygenase. We cloned both genes and expressed the cDNAs in Escherichia coli, confirming their hemoprotein character. Oxygen electrode recordings demonstrated a rapid (> 100 turnovers/s) reaction of the heme dioxygenase with oleic and linoleic acids. HPLC, including chiral column analysis, UV, and GC-MS of the oxygenated products, identified a novel 10S-dioxygenase activity. The catalase-related hemoprotein reacted rapidly and specifically with linoleate 10S-hydroperox-ide (> 2,500 turnovers/s) with a hydroperoxide lyase activity specific for the 10S-hydroperoxy enantiomer. The products were identified by NMR as (8E)10-oxo-decenoic acid and the C8 fragments, 1-octen-3-oland 2Z-octen-1-ol, in ~3:1 ratio. Chiral HPLC analysis established strict enzymatic control in formation of the 3R alcohol configuration (99% enantiomeric excess) and contrasted with racemic 1-octen-3-ol formed in reaction of linoleate 10S-hydroperoxide with hematin or ferrous ions. The Nostoc linoleate 10S-dioxygenase, the sequence of which contains the signature catalytic sequence of cyclooxygenases and fungal linoleate dioxygenases (YRWH), appears to be a heme dioxygenase ancestor. The novel activity of the lyase expands the known reactions of catalase-related proteins and functions in Nostoc in specific transformation of the 10S-hydroperoxylinoleate. [ABSTRACT FROM AUTHOR]