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Escherichia coli possesses four initiator tRNA (i-tRNA) genes, three of which are present together as metZWV and the fourth one as metY. In E. coli B, all four genes (metZWV and metY) encode i-tRNAfMet1, in which the G at position 46 is modified to m7G46 by TrmB (m7G methyltransferase). However, in E. coli K, because of a single-nucleotide polymorphism, metY encodes a variant, i-tRNAfMet2, having an A in place of m7G46. We generated E. coli strains to explore the importance of this polymorphism in i-tRNAs. The strains were sustained either on metYA46 (metY of E. coli K origin encoding i-tRNAfMet2) or its derivative metYG46 (encoding i-tRNAfMet1) in single (chromosomal) or plasmid-borne copies. We show that the strains sustained on i-tRNAfMet1 have a growth fitness advantage over those sustained on i-tRNAfMet2. The growth fitness advantages are more pronounced for the strains sustained on i-tRNAfMet1 in nutrient-rich media than in nutrient-poor media. The growth fitness of the strains correlates well with the relative stabilities of the i-tRNAs in vivo. Furthermore, the atomistic molecular dynamics simulations support the higher stability of i-tRNAfMet1 than that of i-tRNAfMet2. The stability of i-tRNAfMet1 remains unaffected upon the deletion of TrmB. These studies highlight how metYG46 and metYA46 alleles might influence the growth fitness of E. coli under certain nutrient-limiting conditions. IMPORTANCE: Escherichia coli harbors four initiator tRNA (i-tRNA) genes: three of these at metZWV and the fourth one at metY loci. In E. coli B, all four genes encode i-tRNAfMet1. In E. coli K, because of a single-nucleotide polymorphism, metY encodes a variant, i-tRNAfMet2, having an A in place of G at position 46 of i-tRNA sequence in metY. We show that G46 confers stability to i-tRNAfMet1. The strains sustained on i-tRNAfMet1 have a growth fitness advantage over those sustained on i-tRNAfMet2. Strains harboring metYG46 (B mimic) or metYA46 (K mimic) show that while in the nutrient-rich media, the K mimic is outcompeted rapidly; in the nutrient-poor medium, the K mimic is outcompeted less rapidly.
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Selumetinib (SELU) was recently approved by the US Food and Drug Administration (US FDA) in 2020. However, the degradation impurities of SELU have not been characterized or identified to date. The mechanism for impurity formation and the degradation behavior have not been previously studied. This study aims to elucidate the prototypical degradation mechanism of SELU. Furthermore, the degradation impurities have been identified using LC-quadrupole-time-of-flight tandem mass spectrometry and are reported in this article for the first time. In addition, a stability-indicating analytical method (SIAM) has been developed for this drug. Forced degradation studies revealed the degradation of SELU under various stress conditions, including hydrolytic stress (acid and base), oxidative stress, and photolytic stress (ultraviolet and visible). Three degradation impurities were identified. This article presents the first validated SIAM, capable of accurately quantifying SELU in the presence of its degradation impurities. Furthermore, we have proposed the degradation pathway for SELU and its degradation impurities, a first in the field. The developed SIAM can find applications in process development and quality assurance of SELU in both research laboratories and pharmaceutical industries. Moreover, the identified degradation impurities may serve as impurity standards for quality control testing in pharmaceutical industries.
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Contaminação de Medicamentos , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Estabilidade de Medicamentos , Cromatografia Líquida/métodosRESUMO
Duvelisib (DUV) was first approved globally in 2018. An extensive literature search revealed that the differential role of a potential degradation medium in altering the shelf-life of DUV due to its exposure during storage has not been identified till date. Moreover, its degradation impurities and degradation mechanism are not known. In addition, no analytical method has been reported for the quantification of DUV in the presence of its degradation impurities. Therefore, the aim of this study was to identify the impact of different potential degradation media on the stability of DUV, establish the degradation mechanism, and identify its major degradation impurities. The aim was also to establish a stability-indicating analytical method for the quantification of DUV in the presence of its degradation impurities. This study is the first to report the structure of degradation impurities and the step-by-step degradation mechanism of DUV. This information will be useful for the scientific community and manufacturers in optimizing the formulation parameters and/or storage conditions. The validated method can be employed for analysis of stability study and routine quality control samples of newer DUV formulations in pharmaceutical industries. The identified impurities may serve as impurity standards for specifying their limits in the drug after required qualification studies.
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Espectrometria de Massa com Cromatografia Líquida , Espectrometria de Massas em Tandem , Cromatografia Líquida , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Medicamentos , Estabilidade de MedicamentosRESUMO
DK-GV-04P, chemically identified as 3-cinnamyl-2-(4-methoxyphenyl) quinazolin-4(3H)-one, is an investigational molecule synthesized at the Chemical Biology Laboratory of the National Institute of Pharmaceutical Education and Research-Ahmedabad. The compound has shown potential anticancer activity against squamous CAL27 cell lines. Metabolite identification and characterization are critical in drug discovery, providing key insights into a compound's pharmacokinetics, pharmacodynamics safety, and metabolic fate. The primary aim of the study was to identify and characterize the in vitro metabolites of DK-GV-04P. In silico identification of the site of metabolism was also carried out using xenosite online software. The molecule was incubated with human liver microsomes and human S9 liver fraction to generate in vitro metabolites, which were further identified and characterized using ultra-high-performance liquid chromatography-quadrupole time of flight tandem mass spectrometry. A total of nine metabolites (four phase I and five phase II) were identified and characterized through tandem mass spectrometry. The major biotransformation pathways involved in metabolism of DK-GV-04P were hydroxylation, O-demethylation and glucuronidation. In addition to this, a detailed biotransformation pathway of DK-GV-04P has been established in this study.
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Microssomos Hepáticos , Espectrometria de Massas em Tandem , Humanos , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Microssomos Hepáticos/metabolismo , Software , Descoberta de DrogasRESUMO
Most antiretrovirals (ARVs) have intracellular therapeutic target sites and therefore, their plasma concentration may be misleading when relating to their efficacy or toxicity. A bioanalytical method for quantification of the ARV drug bictegravir (BTG) in its target site peripheral blood mononuclear cells (PBMCs) is not available till date. This is the first time to establish a sufficiently sensitive mass spectrometry-based bioanalytical method to quantify BTG in both rat PBMCs and plasma. The developed method was validated over the range of 1 ng/ml to 100 ng/ml and 0.005 ng-10ng/sample for plasma and PBMCs, respectively. For PBMCs, average accuracy and precision at four quality control levels were found to be 93.30%-110.00% and 6.52%-8.25%, respectively. Plasma and intracellular pharmacokinetics of BTG was evaluated by the developed method in rats and a lack of accumulation of BTG in the PBMCs was observed. Pearson correlation coefficient data analysis indicated a moderated correlation between plasma and PBMC concentration of BTG. Therefore, it will be beneficial to include a quantification plan for BTG in its actual therapeutic target site during all its future research and development work. This reported method can be useful for site-specific monitoring of BTG in research laboratories and pharmaceutical industries.
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Leucócitos Mononucleares , Espectrometria de Massas em Tandem , Animais , Ratos , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida/métodos , Amidas , Reprodutibilidade dos TestesRESUMO
RATIONALE: Capmatinib (CMT) has been recently approved for the treatment of non-small cell lung cancer by the United States Food and Drug Administration (USFDA). Till date, the degradation mechanism of CMT in different stress conditions is not known. Moreover, degradation products (DPs) of the drug are yet to be identified. Characterization study on degradation products of CMT has not been reported before. Furthermore, no previously reported literature is available on the stability-indicating method of CMT. METHODS: Owing to the lack of such scientific reports, we developed a sensitive, stability-indicating method for CMT which can resolve it from all its degradation products. The method was validated as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH Q2 [R1]) guideline. We studied and established the degradation mechanism of CMT in different stress conditions. One degradation product (DP2) was isolated and characterized using 1 H NMR. RESULTS: The degradation products (DP1, DP2 and DP3) of the drug have been identified and characterized for the first time by using high-resolution mass spectrometry and 1 H NMR spectroscopy. CMT was found to become degraded under acidic, basic and photolytic stress conditions in the solution phase to yield three major DPs. The drug was found to be stable in neutral hydrolysis, oxidation and thermal stress conditions. CONCLUSIONS: DP1 was formed under acidic and basic hydrolytic conditions, whereas DP2 and DP3 were formed under photolytic conditions. Characterization of all the DPs has been carried out to establish their structures and understand the molecular mechanism behind the degradation of the drug. Few studies reported quantitative analysis of CMT and its metabolites in biological fluids. However, this is the first study to identify the unknown DPs of CMT and the mechanism of its degradation. Moreover, this article reports a stability-indicating analytical method for CMT which has not yet been reported in any literature.
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Carcinoma Pulmonar de Células não Pequenas , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cromatografia Líquida de Alta Pressão/métodos , Estabilidade de Medicamentos , Hidrólise , Neoplasias Pulmonares/tratamento farmacológico , Oxirredução , Fotólise , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodosRESUMO
Pyruvate kinase (PK) M2 activators ramp up glycolysis in cancer cells, leading to a reversal of the Warburg effect in cancer cells. A promising PKM2 activator molecule, IMID-2, developed by the National Institute of Pharmaceutical Education and Research-Ahmedabad showed promising anticancer activity against MCF-7 and COLO-205 cell lines, which represent breast and colon cancer. Its physicochemical properties, like solubility, ionization constant, partition coefficient and distribution constant, have already been established. Its metabolic pathway is also well established through in vitro and in vivo metabolite profiling and reported previously. In this study, we have evaluated the metabolic stability of IMID-2 using LC-MS/MS and investigated the safety aspect of the molecule through an acute oral toxicity study. In vivo studies in rats confirmed that the molecule is safe even at a dose level of 175 mg/kg. Furthermore, a pharmacokinetic study of IMID-2 was also carried out using LC-MS/MS to understand its absorption, distribution, metabolism, and excretion profile. The molecule was found to have promising bioavailability through the oral route. This research work is thus another step in the drug testing of this promising anticancer molecule. The molecule can be considered to be a potential anticancer lead based on the earlier report substantiated by current findings.
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Descoberta de Drogas , Espectrometria de Massas em Tandem , Ratos , Animais , Cromatografia Líquida , Disponibilidade BiológicaRESUMO
Induction of drug-metabolizing enzymes and efflux transporters (DMET) through activation of pregnane x receptor (PXR) is the primary factor involved in almost all bioavailability and drug resistance-related problems of anticancer drugs. PXR is a transcriptional regulator of many metabolizing enzymes and efflux transporters proteins like p-glycoprotein (p-gp), multidrug resistant protein 1 and 2 (MRP 1 and 2), and breast cancer resistant protein (BCRP), etc. Several anticancer drugs are potent activators of PXR receptors and can modulate the gene expression of DMET proteins. Involvement of anticancer drugs in transcriptional regulation of DMET can prompt increased metabolism and efflux of their own or other co-administered drugs, which leads to poor site-specific bioavailability and increased drug resistance. In this review, we have discussed several novel strategies to evade drug-induced PXR activation and p-gp efflux including assessment of PXR ligand and p-gp substrate at early stages of drug discovery. Additionally, we have critically discussed the chemical structure and drug delivery-based approaches to avoid PXR binding and inhibit the p-gp activity of the drugs at their target sites.
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Antineoplásicos , Receptores de Esteroides , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/farmacologia , Descoberta de Drogas , Resistência a Múltiplos Medicamentos , Humanos , Metabolômica , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Preparações Farmacêuticas , Receptores de Esteroides/metabolismoRESUMO
RATIONALE: Metabolite profiling is an integral part of the drug development process for selecting candidates with high therapeutic efficacy and low risk. Baricitinib (BARI) was approved in 2018 by the US Food and Drug Administration to treat rheumatoid arthritis. According to the available literature, no systematic study has been reported on the metabolite profiling of BARI. The biotransformation pathway of the drug has also not been established until recently. This study aims to identify BARI metabolites generated in in vitro matrices. METHODS: The in vitro metabolism study was carried out using rat liver microsome, human liver microsomes, and human S9 fraction. Ultra high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (U-HPLC-Q/TOF) and ultra-high-performance liquid chromatography/linear ion trap-Orbitrap mass spectrometry (U-HPLC/LTQ-Orbitrap-MS/MS) were used to identify and characterize the metabolites of BARI. The in silico toxicity of BARI and its metabolite was studied using ProTox-II toxicity predictor software. RESULTS: A total of five new metabolites have been identified amongst which two (M1 and M2) were detected on both U-HPLC/LTQ-Orbitrap-MS/MS and U-HPLC-Q/TOF and two additional metabolites (M4 and M5) were detected on U-HPLC/LTQ-Orbitrap-MS/MS. Moreover, one metabolite (M3) was only detected on LC-QTOF. CONCLUSIONS: The major metabolic changes were found to be N-dealkylation, demethylation, hydroxylation, and hydrolysis. Metabolites M3 and M4 were found to have the potential for carcinogenicity. The novelty of the study can be justified by the unavailability of any previous research on in vitro metabolite profiling of BARI. Furthermore, this is the first time the biotransformation pathway of BARI and the toxicity potential of its metabolites have been reported.
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Microssomos Hepáticos , Espectrometria de Massas em Tandem , Animais , Azetidinas , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Microssomos Hepáticos/metabolismo , Protoporfirinogênio Oxidase/metabolismo , Purinas , Pirazóis , Ratos , Sulfonamidas , Espectrometria de Massas em Tandem/métodosRESUMO
Duvelisib is a dual inhibitor of phosphoinositide 3 kinase that received global approval by the US Food and Drug Administration in 2018 to treat follicular lymphoma after at least two prior systemic therapies. An extensive literature search revealed that, to date, metabolites of duvelisib have not been characterized and information on them is not available in any of the literature. Moreover, the metabolism pathway is yet to be established. This study aimed to investigate and characterize the metabolites of duvelisib generated in microsomes and S9 fractions. In this study, five duvelisib metabolites were identified using UHPLC-Q-TOF-MS/MS analysis technique. The structural characterization of the metabolites was performed by comparing the fragmentation pattern of duvelisib and its metabolites through an accurate mass measurement technique. Three metabolites were generated through phase I hydroxylation and dechlorination reactions. The other two metabolites were generated through a phase II glucuronidation reaction. The metabolism mechanism established through this study can be useful to improve the safety profile of drugs of similar categories in the future after establishment of the toxicity profile of the identified metabolites.
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Fosfatidilinositol 3-Quinases , Espectrometria de Massas em Tandem , Cromatografia Líquida de Alta Pressão/métodos , Isoquinolinas , Purinas , Espectrometria de Massas em Tandem/métodosRESUMO
Brexpiprazole (BRX) is approved for the treatment of schizophrenia and major depressive disorders and it is mainly metabolized by CYP3A4 and CYP2D6. Grapefruit juice (GFJ), pomegranate juice (PJ) and tomato juice (TJ) have the potential to inhibit CYP3A4 enzymes in the body. However, fruit juice-drug interactions between BRX and GFJ, PJ and TJ have not been studied extensively. The present study describes the influence of GFJ, PJ and TJ on the pharmacokinetic parameters of BRX in rats. The study samples were analyzed using a mass-accurate and single-step bioanalytical method by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry over a wide calibration range of 20-1,500 ng/ml. The results of the pharmacokinetic study denoted that the combined administration of GFJ and PJ could increase systemic exposure of BRX. The area under the curve of BRX increased 3.43- and 1.88-fold with co-administration of GFJ and PJ, respectively, while TJ with BRX had no effect on the area under the curve. Time to peak concentration and half-life were not significantly changed by any juice co-administration. The results show that GFJ and PJ affect the pharmacokinetic profile of BRX and hence advice needs to be given to patients.
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Cromatografia Líquida de Alta Pressão/métodos , Sucos de Frutas e Vegetais , Espectrometria de Massas/métodos , Quinolonas , Tiofenos , Animais , Citrus paradisi/química , Interações Ervas-Drogas , Limite de Detecção , Modelos Lineares , Solanum lycopersicum/química , Masculino , Punica granatum/química , Quinolonas/análise , Quinolonas/farmacocinética , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Tiofenos/análise , Tiofenos/farmacocinéticaRESUMO
Treatment through a combination of drugs involving cyclin D-dependent kinase inhibitors like abemaciclib and aromatase inhibitor like letrozole proved to be a potential therapeutic regimen and first-line treatment in estrogen receptor-positive breast cancer. In this study, we developed a simple and simultaneous RP-HPLC bioanalytical method for quantifying abemaciclib and letrozole in rat plasma. Abemaciclib and letrozole were separated on Zorbax Eclipse C18 column employing a gradient elution method comprising 10 mM ammonium acetate (pH 5) and acetonitrile as mobile phase. The method was found to have acceptable selectivity, accuracy (97.20-118.17%), precision (1.10-9.39%) and stability in the validation experiment performed as per the US Food and Drug Administration guidelines. The method sensitivity was low at a concentration level of 100 ng/ml. The applicability of the method has been verified through a single-dose oral pharmacokinetic study in rat. The developed method will be useful to quantitate the analytes in rat plasma samples of different preclinical studies including their pharmacokinetic drug-drug interactions in the future. To date, no method has been reported for the quantification of abemaciclib and letrozole simultaneously in any type of biological matrices. Therefore, this study makes a definite significant contribution in the field of bioanalytical research.
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Aminopiridinas/sangue , Aminopiridinas/farmacocinética , Benzimidazóis/sangue , Benzimidazóis/farmacocinética , Letrozol/sangue , Letrozol/farmacocinética , Aminopiridinas/química , Animais , Benzimidazóis/química , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Letrozol/química , Limite de Detecção , Modelos Lineares , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos TestesRESUMO
The combination of acebrophylline (ABP), levocetirizine (LCZ) and pranlukast (PRN) is used to treat allergic rhinitis, asthma, hay-fever and other conditions where patients experience difficulty in breathing. This study was carried out with the aim of developing and validating a reverse-phase high-performance liquid chromatographic bioanalytical method to simultaneously quantitate ABP, LCZ and PRN in rat plasma. The objective also includes determination of the pharmacokinetic interaction of these three drugs after administration via the oral route after individual and combination treatment in rat. Optimum resolution between the analytes was observed with a C18 Kinetex column (250 mm × 4.6 mm × 5 µm). The chromatography was performed in a gradient elution mode with a 1 mL/min flow rate. The calibration curves were linear over the concentration range of 100-1600 ng/mL. The intra- and inter-day precision and accuracy were found to be within acceptable limits as specified in US Food and Drug Administration guideline for bioanalytical method validation. The analytes were stable on the bench-top (8 h), after three freeze-thaw cycles, in the autosampler (8 h) and as a dry extract (-80°C for 48 h). The statistical results of the pharmacokinetic study in Sprague-Dawley rats showed a significant change in pharmacokinetic parameters for PRN upon co-administration of the three drugs.
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Ambroxol/análogos & derivados , Cetirizina , Cromonas , Teofilina/análogos & derivados , Ambroxol/sangue , Ambroxol/química , Ambroxol/farmacocinética , Animais , Cetirizina/sangue , Cetirizina/química , Cetirizina/farmacocinética , Cromatografia Líquida de Alta Pressão , Cromonas/sangue , Cromonas/química , Cromonas/farmacocinética , Limite de Detecção , Modelos Lineares , Masculino , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Teofilina/sangue , Teofilina/química , Teofilina/farmacocinéticaRESUMO
Rubber band constriction syndrome has been described in the literature, although there are very few case reports. Non-healing recurrent tenosynovitis and synovitis of the wrist joint demonstrating a circular rubber band on imaging has not been described before. Imaging studies showed retained circular band deep to the extensor tendons, embedded within the joint capsule. Surgical removal of the band by open incision led to a dramatic improvement in the outcome of the patient. Level of evidence V.
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Rheumatologic diseases are a widespread group of disorders affecting the joints, bones, and connective tissue, and leading to significant disability. Imaging is an indispensable component in diagnosing, assessing, monitoring, and managing these disorders, providing information about the structural and functional alterations occurring within the affected joints and tissues. This review article aims to compare the utility, specific clinical applications, advantages, and limitations of high-resolution ultrasound and magnetic resonance imaging in the context of rheumatologic diseases. It also provides insights into the imaging features of various types of inflammatory arthritis with clinical relevance and a focus on high-resolution ultrasound and magnetic resonance imaging. By understanding the comparative aspects of high-resolution ultrasound and magnetic resonance imaging, it is easier for the treating physicians to make informed decisions when selecting the optimal imaging modality for specific diagnostic purposes, effective treatment planning, and improve patient outcomes. The patterns of soft tissue and joint involvement; bony erosion and synovitis help in differentiating between various type of arthritis. Involvement of various small joints of the hands also gives an insight into the type of arthritis. We also briefly discuss the potential applications of emerging techniques, such as ultrasound elastography, contrast-enhanced ultrasound, and dual-energy CT, in the field of rheumatology.
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Rotator cuff tears are common shoulder injuries in patients above 40 years of age, causing pain, disability, and reduced quality of life. Most recurrent rotator cuff tears happen within three months. Surgical repair is often necessary in patients with large or symptomatic tears to restore shoulder function and relieve symptoms. However, 25% of patients experience pain and dysfunction even after successful surgery. Imaging plays an essential role in evaluating patients with postoperative rotator cuff pain. The ultrasound and magnetic resonance imaging are the most commonly used imaging modalities for evaluating rotator cuff. The ultrasound is sometimes the preferred first-line imaging modality, given its easy availability, lower cost, ability to perform dynamic tendon evaluation, and reduced post-surgical artifacts compared to magnetic resonance imaging. It may also be superior in terms of earlier diagnosis of smaller re-tears. Magnetic resonance imaging is better for assessing the extent of larger tears and for detecting other complications of rotator cuff surgery, such as hardware failure and infection. However, postoperative imaging of the rotator cuff can be challenging due to the presence of hardware and variable appearance of the repaired tendon, which can be confused with a re-tear. This review aims to provide an overview of the current practice and findings of postoperative imaging of the rotator cuff using magnetic resonance imaging and ultrasound. We discuss the advantages and limitations of each modality and the normal and abnormal imaging appearance of repaired rotator cuff tendon.
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Chromatography and mass spectrometry based techniques are the most commonly employed procedures to quantitate the analytes in pharmaceutical research. However, sensitivity of analytical methods significantly varies due to the difference in physicochemical characteristics of analytes. Sensitivity of methods greatly affects the quality of analytical results. Establishment of a sufficiently sensitive method ensures the suitability of a technique for its intended purpose. Although various types of advancement in chromatographic science are witnessed, issues related to sensitivity remain a major challenge for the analyte with low detection limit. Highly sensitive analytical methods are specifically essential to quantitate the analytes in the samples from dissolution study of sustained release formulations, cross-contamination study, impurity analysis, metabolite profiling, bioanalysis of highly potent and low bioavailable drugs. In recent years, huge involvement of researchers toward sensitivity enhancement of quantitative methods is evidenced. Wide verities of approaches are being reported in the field. Derivatization technique, introduction of ion-pairing reagents, sample pretreatment, and utilization of innovative methods such as 2-dimensional liquid chromatography, nano liquid chromatography, 2-dimensional gas chromatography, supercritical fluid chromatography, use of microcolumn are some approaches that are being employed. Online sample preparation techniques can significantly improve the sensitivity of a method by reducing sample loss and degradation. This review summarizes and critically discussed the approaches to improve the sensitivity of chromatographic and mass spectrometry based analytical methods. This article can guide the researchers to select suitable approaches for achieving the desired detection limit of analytical and bioanalytical methods based on their specific requirements.
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Cromatografia com Fluido Supercrítico , Cromatografia Líquida/métodos , Espectrometria de Massas/métodosRESUMO
Accurate quantification of biomarkers has always been a challenge for many bioanalytical scientists due to their endogenous nature and low concentration in biological matrices. Different analytical approaches have been developed for quantifying biomarkers including enzyme-linked immunosorbent assay, immunohistochemistry, western blotting, and chromatographic techniques assisted with mass spectrometry. Liquid chromatography-tandem mass spectrometry-based quantification of biomarkers has gained more attention over other traditional techniques due to its higher sensitivity and selectivity. However, the primary challenge lies with this technique includes the unavailability of a blank matrix for method development. To overcome this challenge, different analytical approaches are being developed including surrogate analyte and surrogate matrix approach. Such approaches include quantification of biomarkers in a surrogate matrix or quantification of an isotopically labeled surrogate analyte in an authentic matrix. To demonstrate the authenticity of the surrogate approach, it is mandatory to establish quantitative parallelism through validation employing respective surrogate analytes and surrogate matrices. In this review, different bioanalytical approaches for biomarker quantification and recent advancements in the field aiming for improvement in the specificity of the techniques have been discussed. Liquid chromatography-tandem mass spectrometry-based surrogate approaches for biomarker quantification and significance of parallelism establishment in both surrogate matrix and surrogate analyte-based approaches have been critically discussed. In addition, different methods for demonstrating parallelism in the surrogate method have been explained.
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Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida/métodos , BiomarcadoresRESUMO
The aim of the present study is to identify actinobacteria Streptomyces bacillaris ANS2 as the source of the potentially beneficial compound 2,4-di-tert-butylphenol, describe its chemical components, and assess its anti-tubercular (TB) and anti-cancer properties. Ethyl acetate was used in the agar surface fermentation of S. bacillaris ANS2 to produce the bioactive metabolites. Using various chromatographic and spectroscopy analyses, the potential bioactive metabolite separated and identified as 2,4-di-tert-butylphenol (2,4-DTBP). The lead compound 2,4-DTBP inhibited 78% and 74% of relative light unit (RLU) decrease against MDR Mycobacterium tuberculosis at 100ug/ml and 50ug/ml concentrations, respectively. The Wayne model was used to assess the latent/dormant potential in M. tuberculosis H37RV at various doses, and the MIC for the isolated molecule was found to be 100ug/ml. Furthermore, the molecular docking of 2,4-DTBP was docked using Autodock Vinasuite onto the substrate binding site of the target Mycobacterium lysine aminotransferase (LAT) and the grid box was configured for the docking run to cover the whole LAT dimer interface. At a dosage of 1 mg/ml, the anti-cancer activity of the compound 2,4-DTBP was 88% and 89% inhibited against the HT 29 (colon cancer) and HeLa (cervical cancer) cell lines. According to our literature survey, this present finding may be the first report on anti-TB activity of 2,4-DTBP and has the potential to become an effective natural source and the promising pharmaceutical drug in the future.
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Mycobacterium tuberculosis , Neoplasias , Simulação de Acoplamento Molecular , Linhagem Celular , Antituberculosos/farmacologiaRESUMO
Marine-derived actinobacteria have tremendous potential to produce novel metabolites with diverse biological activities. The Andaman coast of India has a lot of microbial diversity, but it is still a relatively unknown ecology for isolating novel actinobacteria with beneficial bioactive compounds. We have isolated 568 actinobacterial strains from mangrove rhizosphere sediments and sponge samples. Crude extracts from 75 distinct strains were produced by agar surface fermentation and extracted using ethyl acetate. In the disc diffusion method, 25 actinobacterial strains showed antimicrobial activity; notably, the strain MAB56 demonstrated promising broad-spectrum activity. Strain MAB56 was identified as Streptomyces albus by cultural, microscopic, and molecular methods. Conditions for bioactive metabolites from MAB56 were optimized and produced in a lab-scale fermenter. Three active metabolites (C1, C2, and C3) that showed promising broad-spectrum antimicrobial activity were isolated through HPLC-based purification. Based on the UV, FT-IR, NMR, and LC-MS analysis, the chemical nature of the active compounds was confirmed as 12-methyltetradecanoic acid (C1), palmitic acid (C2), and tridecanoic acid (C3) with molecular formulae C14H28O2, C16H32O2, and C13H26O2, respectively. Interestingly, palmitic acid (C2) also exhibited anti-HIV activity with an IC50 value of < 1 µg/ml. Our findings reveal that the actinobacteria from the Andaman marine ecosystems are promising for isolating anti-infective metabolites.