scholarly journals Characterization of Phase I Hepatic Metabolites of Anti-Premature Ejaculation Drug Dapoxetine by UHPLC-ESI-Q-TOF

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3794
Author(s):  
Robert Skibiński ◽  
Jakub Trawiński ◽  
Maciej Gawlik

Determination of the metabolism pathway of xenobiotics undergoing the hepatic pass is a crucial aspect in drug development since the presence of toxic biotransformation products may result in significant side effects during the therapy. In this study, the complete hepatic metabolism pathway of dapoxetine established according to the human liver microsome assay with the use of a high-resolution LC–MS system was described. Eleven biotransformation products of dapoxetine, including eight metabolites not reported in the literature so far, were detected and identified. N-dealkylation, hydroxylation, N-oxidation and dearylation were found to be the main metabolic reactions for the investigated xenobiotic. In silico analysis of toxicity revealed that the reaction of didesmethylation may contribute to the increased carcinogenic potential of dapoxetine metabolites. On the other hand, N-oxidation and aromatic hydroxylation biotransformation reactions possibly lead to the formation of mutagenic compounds.

2019 ◽  
Vol 13 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Vishal Ahuja ◽  
Aashima Sharma ◽  
Ranju Kumari Rathour ◽  
Vaishali Sharma ◽  
Nidhi Rana ◽  
...  

Background: Lignocellulosic residues generated by various anthropogenic activities can be a potential raw material for many commercial products such as biofuels, organic acids and nutraceuticals including xylitol. Xylitol is a low-calorie nutritive sweetener for diabetic patients. Microbial production of xylitol can be helpful in overcoming the drawbacks of traditional chemical production process and lowring cost of production. Objective: Designing efficient production process needs the characterization of required enzyme/s. Hence current work was focused on in-vitro and in-silico characterization of xylose reductase from Emericella nidulans. Methods: Xylose reductase from one of the hyper-producer isolates, Emericella nidulans Xlt-11 was used for in-vitro characterization. For in-silico characterization, XR sequence (Accession No: Q5BGA7) was used. Results: Xylose reductase from various microorganisms has been studied but the quest for better enzymes, their stability at higher temperature and pH still continues. Xylose reductase from Emericella nidulans Xlt-11 was found NADH dependent and utilizes xylose as its sole substrate for xylitol production. In comparison to whole cells, enzyme exhibited higher enzyme activity at lower cofactor concentration and could tolerate higher substrate concentration. Thermal deactivation profile showed that whole cell catalysts were more stable than enzyme at higher temperature. In-silico analysis of XR sequence from Emericella nidulans (Accession No: Q5BGA7) suggested that the structure was dominated by random coiling. Enzyme sequences have conserved active site with net negative charge and PI value in acidic pH range. Conclusion: Current investigation supported the enzyme’s specific application i.e. bioconversion of xylose to xylitol due to its higher selectivity. In-silico analysis may provide significant structural and physiological information for modifications and improved stability.


Metallomics ◽  
2021 ◽  
Vol 13 (3) ◽  
Author(s):  
Shi-Yong Zhu ◽  
Li-Li Liu ◽  
Yue-Qiang Huang ◽  
Xiao-Wei Li ◽  
Milton Talukder ◽  
...  

Abstract Selenoprotein N (SEPN1) is critical to the normal muscular physiology. Mutation of SEPN1 can raise congenital muscular disorder in human. It is also central to maturation and structure of skeletal muscle in chicken. However, human SEPN1 contained an EF-hand motif, which was not found in chicken. And the biochemical and molecular characterization of chicken SEPN1 remains unclear. Hence, protein domains, transcription factors, and interactions of Ca2+ in SEPN1 were analyzed in silico to provide the divergence and homology between chicken and human in this work. The results showed that vertebrates’ SEPN1 evolved from a common ancestor. Human and chicken's SEPN1 shared a conserved CUGS-helix domain with function in antioxidant protection. SEPN1 might be a downstream target of JNK pathway, and it could respond to multiple stresses. Human's SEPN1 might not combine with Ca2+ with a single EF-hand motif in calcium homeostasis, and chicken SEPN1 did not have the EF-hand motif in the prediction, indicating the EF-hand motif malfunctioned in chicken SEPN1.


2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Francesca Caccuri ◽  
Alberto Zani ◽  
Serena Messali ◽  
Marta Giovanetti ◽  
Antonella Bugatti ◽  
...  

Abstract Background Since the first outbreak of SARS-CoV-2, the clinical characteristics of the Coronavirus Disease 2019 (COVID-19) have been progressively changed. Data reporting a viral intra-host and inter-host evolution favouring the appearance of mild SARS-CoV-2 strains are since being accumulating. To better understand the evolution of SARS-CoV-2 pathogenicity and its adaptation to the host, it is therefore crucial to investigate the genetic and phenotypic characteristics of SARS-CoV-2 strains circulating lately in the epidemic. Methods Nasopharyngeal swabs have been analyzed for viral load in the early (March 2020) and late (May 2020) phases of epidemic in Brescia, Italy. Isolation of SARS-CoV-2 from 2 high viral load specimens identified on March 9 (AP66) and on May 8 (GZ69) was performed on Vero E6 cells. Amount of virus released was assessed by quantitative PCR. Genotypic characterization of AP66 and GZ69 was performed by next generation sequencing followed by an in-depth in silico analysis of nucleotide mutations. Results The SARS-CoV-2 GZ69 strain, isolated in May from an asymptomatic healthcare worker, showed an unprecedented capability of replication in Vero E6 cells in the absence of any evident cytopathic effect. Vero E6 subculturing, up to passage 4, showed that SARS-CoV-2 GZ69 infection was as productive as the one sustained by the cytopathic strain AP66. Whole genome sequencing of the persistently replicating SARS-CoV-2 GZ69 has shown that this strain differs from the early AP66 variant in 9 nucleotide positions (C2939T; C3828T; G21784T; T21846C; T24631C; G28881A; G28882A; G28883C; G29810T) which lead to 6 non-synonymous substitutions spanning on ORF1ab (P892S; S1188L), S (K74N; I95T) and N (R203K, G204R) proteins. Conclusions Identification of the peculiar SARS-CoV-2 GZ69 strain in the late Italian epidemic highlights the need to better characterize viral variants circulating among asymptomatic or paucisymptomatic individuals. The current approach could unravel the ways for future studies aimed at analyzing the selection process which favours viral mutations in the human host.


2008 ◽  
Vol 34 (3) ◽  
pp. 265-276 ◽  
Author(s):  
Mark D. Parker ◽  
Patrice Bouyer ◽  
Christopher M. Daly ◽  
Walter F. Boron

The reported sequences of the human and mouse Na+-driven Cl−/HCO3− exchangers (NDCBEs) differ greatly in their extreme cytosolic COOH termini (Ct). In human NDCBE (NDCBE-B), a 17-amino acid (aa) sequence replaces 66 aa at the equivalent position in mouse NDCBE (NDCBE-A). We performed 5′- and 3′-rapid amplification of cDNA ends (RACE) on human brain cDNA, followed by PCR of full-length cDNAs to determine whether the human SLC4A8 gene was capable of producing the mouselike Ct sequence. Our study confirmed the presence in human cDNA of mouse NDCBE-like transcripts (human NDCBE-A) and also disclosed the existence of three further novel NDCBE transcripts that we have called NDCBE-C, NDCBE-D, and NDCBE-D′. The novel NDCBE-C/D/D′ transcripts initiate at a novel “exon 0” positioned ∼35 kb upstream of the first exon of NDCBE-A/B. NDCBE-C/D/D′ protein products are predicted to be truncated by 54 aa in the cytosolic NH2 terminus (Nt) compared with NDCBE-A/B. Our data, combined with a new in silico analysis of partial transcripts reported by others in the region of the human SLC4A8 gene, increase the known extent of the SLC4A8 gene by 49 kb, to 124 kb. A functional comparison of NDCBE-A/B/C/D expressed in Xenopus oocytes demonstrates that the Nt variation does not affect the basal functional expression of NDCBE, but those with the shorter Ct have a 25–50% reduced functional expression compared with those with the longer Ct. By comparison with an artificially truncated NDCBE that contains neither 17-aa nor 66-aa Ct cassette, we determined that the functional difference is unrelated to the 66-aa cassette of NDCBE-A/C, but is instead due to an inhibitory effect of the 17-aa cassette of NDCBE-B/D.


2018 ◽  
Vol 3 (02) ◽  
pp. 150-157
Author(s):  
Asad Amir ◽  
Neelesh Kapoor ◽  
Hirdesh Kumar ◽  
Mohd. Tariq ◽  
Mohd. Asif Siddiqui

Sandalwood is a commercially and culturally important plant species belonging to the family Santalaceae and the genus Santalum. In Indian sandalwood is renowned for its oil, which is highly rated for its sweet, fragrant, persistent aroma and the fixative property which is highly demanded by the perfume industry. For better production and varieties, requires to understanding the functions of proteins, their analysis and characterization of proteins sequences and their structures, their localizations in cell and their interaction with other functional partner. Due to limited number of in silico studies on sandalwood, in the present study we have performed in silico analysis by characterization of sandalwood proteins. Total 23 proteins were obtained and characterization using UniProtKB, identifying their physico-chemical parameters using ProtParam tool and prediction of their secondary structure elements using GOR of all 23 proteins.


2006 ◽  
Vol 73 (2) ◽  
pp. 545-553 ◽  
Author(s):  
Alain Mazé ◽  
Mary O'Connell-Motherway ◽  
Gerald F. Fitzgerald ◽  
Josef Deutscher ◽  
Douwe van Sinderen

ABSTRACT In silico analysis of the Bifidobacterium breve UCC2003 genome allowed identification of four genetic loci, each of which specifies a putative enzyme II (EII) protein of a phosphoenolpyruvate:sugar phosphotransferase system. The EII encoded by fruA, a clear homologue of the unique EIIBCA enzyme encoded by the Bifidobacterium longum NCC2705 genome, was studied in more detail. The fruA gene is part of an operon which contains fruT, which is predicted to encode a homologue of the Bacillus subtilis antiterminator LicT. Transcriptional analysis showed that the fru operon is induced by fructose. The genetic structure, complementation studies, and the observed transcription pattern of the fru operon suggest that the EII encoded in B. breve is involved in fructose transport and that its expression is controlled by an antiterminator mechanism. Biochemical studies unequivocally demonstrated that FruA phosphorylates fructose at the C-6 position.


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