Carbazochrome sodium sulfonate is not effective for prevention of post-gastric endoscopic submucosal dissection bleeding: A retrospective study.

BACKGROUND: Carbazochrome sodium sulfonate (CSS) is conventionally administered to prevent post-endoscopic submucosal dissection (ESD) bleeding in many institutions, but research on its preventive efficacy is lacking. Therefore, we investigated the risk of post-ESD bleeding and the preventive efficacy of CSS administration. METHODS: We retrospectively reviewed 304 lesions in 259 patients with gastric neoplasms who underwent ESD at Asahikawa Medical University Hospital from 2014 to 2021. In the CSS group, CSS 100 mg/day was intravenously infused with maintenance fluid replacement on postoperative days 0-2. The risk factors of post-ESD bleeding, including CSS administration, were investigated. RESULTS: The overall rate of post-ESD bleeding was 4.6% (14/304). The univariate analysis showed that atrial fibrillation (Af), warfarin intake, heparin replacement, and tumor location in the lower third were significant risk factors for increasing the likelihood of postoperative bleeding. In the multivariate analysis, Af (odds ratio [OR] 3.83, 95% CI 1.02-14.30; p < 0.05), heparin replacement (OR 4.60, 95% CI 1.02-20.70; p < 0.05), and tumor location in the lower third of the stomach (OR 6.67, 95% CI 1.43-31.00; p < 0.05) were independent factors for post-ESD bleeding. Post-ESD bleeding was observed in 5.2% (9/174) of the CSS group and 3.8% (5/130) of the non-CSS group, with no significant difference between the two groups (p = 0.783). Additionally, CSS was not shown to have preventive effects in groups with higher-risk factors, such as Af diagnosis, warfarin use, heparin replacement, and tumor location in the lower third of the stomach. CONCLUSION: CSS administration was not effective for the prevention of the post-ESD bleeding in the overall patient population as well as in higher-risk patients. This suggests that the administration of CSS for post-ESD bleeding prevention may need to be reconsidered.

Effects of carbazochrome sodium sulfonate combined with tranexamic acid on hemostasis and inflammation during perioperative period of total hip arthroplasty: A randomized controlled trial.

BACKGROUND: The hemostatic effect of tranexamic acid (TXA) combined with carbazochrome sodium sulfonate (CSS) in total hip arthroplasty (THA) has not been determined. Therefore we performed a randomized study aiming to evaluate the effects of CSS combined with TXA on perioperative blood loss and inflammatory response of THA. HYPOTHESIS: CSS combined with TXA can effectively reduce perioperative blood loss and immune response compared to TXA. MATERIAL AND METHODS: This randomized placebo-controlled trial assigned 150 patients undergoing unilateral primary total hip arthroplasty who underwent direct anterior approach surgery to 3 groups: group A received TXA plus topical CSS; group B received TXA only; and group C received placebo. The main outcome was total blood loss. Secondary outcomes included reduction in hemoglobin concentration, coagulation parameters, inflammatory marker levels, perioperative visual analog scale (VAS) pain score, transfusion rates, postoperative hospital stay, and incidence of thromboembolic events. RESULTS: Total blood loss in group A (668.84±230.95ml) was lower than in group B (940.96±359.22ml) and C (1166.52±342.85ml, p<0.05). We also found that compared with group B, postoperative hip pain, biomarker level of inflammation, visual analogue score (VAS) pain score in group A were significantly improved. The transfusion rate and unit of group A were significantly lower than group C (8 patients; 17.5 units), but there was no statistical difference between group A (no transfusion) and group B (2 patients; 4 units). No differences were observed in thromboembolic and other outcomes among the groups. DISCUSSION: The combined application of topic CSS and TXA is more effective than TXA alone following THA in regard of reducing total blood loss. In addition, CSS combined with TXA is better than TXA alone in terms of improving postoperative hip pain and reducing the level of inflammatory factors. LEVEL OF EVIDENCE: I; randomized controlled study.

Carbazochrome carbon nanotube as drug delivery nanocarrier for anti-bleeding drug: quantum chemical study.

The interaction between drugs and single-walled carbon nanotubes is proving to be of fundamental interest for drug system of delivery and nano-bio-sensing. In this study, the interaction of pristine CNT with carbazochrome, an anti-hemorrhagic or hemostatic agent, was investigated with M06-2X functional and 6-31G* basis set. All probable positions of related adsorption for these kind drugs were thought-out to find out which one is energetically suitable. Based on the achieved data, the stronger interactions appeared the oxygen atom of C = O group and nitrogen atom of imine groups. The topology analysis of QTAIM (quantum theory of atoms in a molecule) method was accomplished to understand the properties of interactions between the CNT and carbazochrome. Frontier molecular orbital energies of all systems, global index including stiffness, softness, chemical Gibbs energies, and electrophilicity parameters, as well as some other important physical data such as dipole moment, polarizability, anisotropy polarisibility, and hyperpolaribility were calculated, evaluated, and then compared together. The essence of the formed bonding model progress along the reaction roots was further validated using electron localization function (ELF) calculations. The highest values of adsorption energies were determined in the range of 18.24 up to 22.12 kcal mol-1 for these kind systems. The acceptable recovery time of 849 s was obtained for the desorption of carbazochrome from the CNT surface under UV-light. The final results exhibit that carbazochrome can serve as a promising carrier and also as sensitive sensors in any kind of practical application.

Neuroprotective Properties of Quinone Reductase 2 Inhibitor M-11, a 2-Mercaptobenzimidazole Derivative.

The ability of NQO2 to increase the production of free radicals under enhanced generation of quinone derivatives of catecholamines is considered to be a component of neurodegenerative disease pathogenesis. The present study aimed to investigate the neuroprotective mechanisms of original NQO2 inhibitor M-11 (2-[2-(3-oxomorpholin-4-il)-ethylthio]-5-ethoxybenzimidazole hydrochloride) in a cellular damage model using NQO2 endogenous substrate adrenochrome (125 µM) and co-substrate BNAH (100 µM). The effects of M-11 (10-100 µM) on the reactive oxygen species (ROS) generation, apoptosis and lesion of nuclear DNA were evaluated using flow cytometry and single-cell gel electrophoresis assay (comet assay). Results were compared with S29434, the reference inhibitor of NQO2. It was found that treatment of HT-22 cells with M-11 results in a decline of ROS production triggered by incubation of cells with NQO2 substrate and co-substrate. Pre-incubation of HT-22 cells with compounds M-11 or S29434 results in a decrease of DNA damage and late apoptotic cell percentage reduction. The obtained results provide a rationale for further development of the M-11 compound as a potential neuroprotective agent.

Varied thyroid disrupting effects of perfluorooctanoic acid (PFOA) and its novel alternatives hexafluoropropylene-oxide-dimer-acid (GenX) and ammonium 4,8-dioxa-3H-perfluorononanoate (ADONA) in vitro.

Due to its potential adverse effects on human health, perfluorooctanoic acid (PFOA), one of the once widely used legacy per- and polyfluoroalkyl substances (PFASs), has been recently replaced by its novel alternatives including hexafluoropropylene-oxide-dimer-acid (GenX) and ammonium 4,8-dioxa-3H-perfluorononanoate (ADONA). These alternative PFASs are detected in water and exposed workers. PFASs can enter organs like thyroids, however, it is yet unknown whether the new alternatives are safer than PFOA. In the current study, we compared the thyroid disrupting effects of PFOA and its alternatives GenX and ADONA in vitro with both rat thyroid cell line FRTL5 and primary normal human thyroid (NHT) cells. Cells were exposed to ascendant doses of PFOA, GenX or ADONA for various incubation time and cell viability was assessed by WST-1 assay and LDH assay. The proliferation rate of survived cells was determined by crystal violet-based cell proliferation assay and MTT assay. The gene expression of thyroid hormone regulation-related genes in thyroid cells after exposure was quantified by RT-PCR and Western blot. Our data showed that both PFOA and GenX reduced thyroid cell viability in both dose and time dependent manner, with GenX being more toxic than PFOA at the same condition. Similarly, the proliferation rate of cells survived exposure to PFOA and GenX was considerably impaired, with GenX showing more profound adverse effect than PFOA. Unlike PFOA and GenX, ADONA showed no apparent adverse effects on the viability and proliferation of both thyroid cell types. Gene expression data revealed that all three PFASs altered gene expression in both thyroid cells and the altered gene expression seemed to be PFAS and cell type dependent. Taken together, our data reveal that the thyroid disrupting effects is increased in the order of GenX > PFOA > ADONA. Our findings will be beneficial for the guidance of the future usage of PFASs and development of better alternatives.

Correction pen as a hydrophobic/lipophobic barrier plotter integrated with paper-based chips and a mini UV-torch to implement all-in-one device for determination of carbazochrome.

The design of a cheap, simple, and handy sensing system for rapid quantitation of pharmaceuticals becomes mandatory to ease drug development procedures, quality control, health care, etc. This work describes a simple, innovative, and easily manufactured paper-based device using a correction pen as a plotter for hydrophobic/lipophobic barriers and graphene quantum dots for recognition and quantification of the hemostatic drug carbazochrome, via fluorescence turn-off mechanism mediated by the inner filter effect. A smartphone-based all-in-one device fitted with an inexpensive 365 nm flashlight as a UV light source and a free image processing software was developed for rapid and reliable interpretation of the fluorescence change from the paper-based device upon introduction of the drug. The simple and convenient steps permit the analysis of many samples in a very short time. The smartphone-based all-in-one device featured excellent sensitivity for carbazochrome with a limit of detection equals to 12 ng/detection zone and good %recovery (100.0 ± 0.4). The reliability of the device was ascertained by favorable statistical comparison with the analogous optimized conventional fluorimetry method and a reference HPLC method. The device has been successfully applied for versatile quantitation of carbazochrome in tablets and on manufacturing equipment surfaces with excellent recoveries. The device offers many green aspects that definitely assist the implementation of the sustainability concept to analytical laboratories. The cost-efficiency, reliability, and ease of fabrication as well as the greenness and user friendship qualify the device for wide application in low-income communities.

Catecholamine oxidation-mediated transcriptional inhibition in Mn neurotoxicity.

Manganese (Mn) poisoning may result in a neurological disorder called manganism. Although the neurotoxic mechanism of Mn is unclear, oxidative stress may be involved based on the interactions between neurotransmitter catecholamines and metals such as iron. Here, we propose a novel mechanism in which Mn oxidizes catecholamines and inhibits cellular transcription. Mn accelerated the oxidation of adrenaline (Ad) and produced adrenochrome (AdC) more effectively than iron. Furthermore, the oxidation of DNA bases increased when Ad, Mn, and iron were present. However, despite the absence of iron, cell viability decreased in the presence of AdC or Ad with Mn, which suggests there is another mechanism independent of oxidative DNA damage. AdC or preincubated Ad with Mn reduced mRNA synthesis in T7 RNA polymerase-driven transcription. RNA synthesis decreased in AdC-treated cells dose-dependently. These results show that Mn disrupts neuronal function via catecholamine oxidation-mediated transcriptional inhibition.

The Effect of Carbazochrome Sodium Sulfonate in Patients with Colonic Diverticular Bleeding: Propensity Score Matching Analyses Using a Nationwide Inpatient Database.

Objective Carbazochrome sodium sulfonate (CSS) has been routinely used to treat bleeding; however, no study has examined the effect of CSS for gastrointestinal bleeding. Therefore, we aimed to investigate the effect of CSS for colonic diverticular bleeding. Methods We performed a nationwide observational study using the Japanese Diagnosis Procedure Combination inpatient database. We identified patients who were admitted for diverticular bleeding from July 2010 to March 2018. Patients who received CSS on the day of admission were defined as the CSS group, and those not receiving CSS were defined as the control group. The primary outcome was in-hospital mortality. Secondary outcomes were length of stay, total costs, and blood transfusion within 7 days of admission. Propensity score matching analyses were performed to compare outcomes between the two groups. Results A total of 59,965 patients met our eligibility criteria. Of these, 14,437 (24%) patients received CSS on the day of admission. One-to-one propensity score matching created 14,379 matched pairs. There was no significant difference in the in-hospital mortality between the CSS and control groups (0.6% vs. 0.5%, respectively; odds ratio: 0.96; 95% confidence interval: 0.72-1.29). The length of stay was longer in the CSS group than in the control group (11.4 vs. 11.0 days, respectively; difference: 0.44; 95% confidence interval: 0.14-0.73). There were no significant differences in the total costs or the proportion of patients receiving blood transfusion between the groups. Conclusions CSS may not reduce in-hospital mortality, length of stay, total costs, or the need for blood transfusion in patients with colonic diverticular bleeding.

Hemostatic and Anti-Inflammatory Effects of Carbazochrome Sodium Sulfonate in Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Postoperative recovery after total knee arthroplasty (TKA) is associated with postoperative anemia, allogeneic transfusion, and stress immune responses to surgery. Carbazochrome sodium sulfonate (CSS) reduces bleeding through several mechanisms. We assessed the effect of CSS combined with tranexamic acid (TXA) on postoperative anemia, blood transfusion, and inflammatory responses. METHODS: This study was designed as a randomized, placebo-controlled trial of 200 patients undergoing unilateral primary TKA. Patients were divided into 4 groups: group A received TXA plus topical and intravenous CSS; group B received TXA plus topical CSS only; group C received TXA plus intravenous CSS only; group D received TXA only. RESULTS: Total blood loss in groups A (609.92 ± 221.24 mL), B (753.16 ± 247.67 mL), and C (829.23 ± 297.45 mL) was lower than in group D (1158.26 ± 334.13 mL, P < .05). There was no difference in total blood loss between groups B and C. We also found that compared with group D, the postoperative swelling rate, biomarker level of inflammation, visual analog scale pain score, and range of motion at discharge in groups A, B, and C were significantly improved (P < .05). No thromboembolic complications occurred. There were no differences in transfusion rate, intraoperative blood loss, platelet count, or average length of stay among the 4 groups (P > .05). CONCLUSION: CSS combined with TXA was more effective than TXA alone in reducing perioperative blood loss and inflammatory response and did not increase the incidence of thromboembolism complications.

Mechanism and impact of catecholamine conversion by Vibrio cholerae.

Bacterial pathogens are influenced by signaling molecules including the catecholamines adrenaline and noradrenaline which are host-derived hormones and neurotransmitters. Adrenaline and noradrenaline modulate growth, motility and virulence of bacteria. We show that adrenaline is converted by the pathogen Vibrio cholerae to adrenochrome in the course of respiration, and demonstrate that superoxide produced by the respiratory, Na+ - translocating NADH:quinone oxidoreductase (NQR) acts as electron acceptor in the oxidative conversion of adrenaline to adrenochrome. Adrenochrome stimulates growth of V. cholerae, and triggers specific responses in V. cholerae and in immune cells. We performed a quantitative proteome analysis of V. cholerae grown in minimal medium with glucose as carbon source without catecholamines, or with adrenaline, noradrenaline or adrenochrome. Significant regulation of proteins participating in iron transport and iron homeostasis, in energy metabolism, and in signaling was observed upon exposure to adrenaline, noradrenaline or adrenochrome. On the host side, adrenochrome inhibited lipopolysaccharide-triggered formation of TNF-α by THP-1 monocytes, though to a lesser extent than adrenaline. It is proposed that adrenochrome produced from adrenaline by respiring V. cholerae functions as effector molecule in pathogen-host interaction.

A randomized, double-blind, placebo-controlled multicenter study for evaluating the effects of fixed-dose combinations of vitamin C, vitamin E, lysozyme, and carbazochrome on gingival inflammation in chronic periodontitis patients.

BACKGROUND: To evaluate gingival inflammation from fixed-dose combinations of vitamin C, vitamin E, lysozyme and carbazochrome (CELC) in the treatment of chronic periodontitis following scaling and root planing. METHODS: One hundred patients were randomly assigned to receive CELC (test) or placebo (control) for the first 4 weeks at a 1:1 ratio, and both groups received CELC for the remaining 4 weeks. Primary outcome was the mean change in the gingival index (GI) after 4 weeks. Secondary outcomes included mean change in GI after 8 weeks and plaque index, probing depth, clinical attachment level, and VAS at 4 weeks and 8 weeks. RESULTS: Ninety-three patients completed the study. The GI in the test group significantly decreased after 4 weeks (p < 0.001) and 8 weeks (p < 0.001). The mean change from baseline in GI significantly decreased in the test group compared to the control group after 4 weeks (p = 0.015). In the GEE model adjusting for age, gender and visits, the test group showed 2.5 times GI improvement compared to the control group (p = 0.022). CONCLUSIONS: Within the study, CELC showed a significant reduction in gingival inflammation compared with a placebo. Other parameters, however, were similar between groups. TRIAL REGISTRATION: KCT0001366 (Clinical Research Information Service, Republic of Korea) and 29 Jan 2015, retrospectively registered.

Pelvic venous congestion induces lower urinary tract dysfunction in rats.

Pelvic venous congestion (PC) is thought to be related to several diseases of the lower urinary tract (LUT). We examined the characteristics of the LUT in rats with PC. To create PC, female rats were anesthetized with isoflurane, and the bilateral common iliac veins and bilateral uterine veins were ligated. At 1-8 weeks after either ligation or sham surgery, we performed cystometry with or without administration of carbazochrome sodium sulfonate hydrate or propiverine hydrochloride, histologic examination of the bladder, blood flow imaging, assessment of locomotor activity, measurement of urinary 8-hydroxydeoxyguanosine (8-OHdG) and nitric oxide metabolites (NOx), and the Evans blue dye extravasation test. PC elevated frequency of urination after 2-6 weeks, and caused a decrease of spontaneous locomotor activity. In addition, there was a decrease of bladder blood flow, an increase of bladder vascular permeability, an increase of urinary 8-OHdG, a decrease of urinary NOx, and mild inflammatory changes of the bladder. In rats with PC, frequency of urination was normalized by administration of propiverine or carbazochrome. Rats with PC may be used as a model of PC associated with high frequency of urination, and this model may be useful when developing treatment for LUT symptoms associated with PC.

Dynamic agent of an injectable and self-healing drug-loaded hydrogel for embolization therapy.

Embolic agents are crucial for trans-catheter arterial embolization (TAE) in the treatment of various unresectable malignant tumors. Although solid particles, liquid oils, and some polymeric hydrogels have proved their capacities for embolic therapies, the low efficiency, time sensitivity, and cytotoxicity are still considered as challenges. In this study, we developed a three-component dynamic self-healing hydrogel to overcome these limitations. With the help of the Schiff-base bonding, both glycol-chitosan and carbazochrome, containing amine groups, react with dibenzaldehyde-terminated poly(ethylene-glycol) (DF-PEG), forming the dynamic self-healing hydrogels under a mild condition within 200 s. 1H NMR and rheology test were used to characterize the Schiff-base formation and mechanical strength. Controlled-release of carbazochrome from different gelator concentrations of DF-PEG was also studied. Furthermore, in vivo evaluation of the embolization on rats showed the superior embolic effects of the injectable and self-healing hydrogel. Therefore, this new dynamic agent demonstrated the potential for application as a simple, inexpensive, and tunable embolic agent for cancer treatment and drug delivery system.

Oxidative stress and neurodegeneration: The possible contribution of quinone reductase 2.

There is increasing evidence that oxidative stress is involved in the etiology and pathogenesis of neurodegenerative disorders. Overproduction of reactive oxygen species (ROS) is due in part to the reactivity of catecholamines, such as dopamine, adrenaline, and noradrenaline. These molecules are rapidly converted, chemically or enzymatically, into catechol-quinone and then into highly deleterious semiquinone radicals after 1-electron reduction in cells. Notably, the overexpression of dihydronicotinamide riboside:quinone oxidoreductase (QR2) in Chinese hamster ovary (CHO) cells increases the production of ROS, mainly superoxide radicals, when it is exposed to exogenous catechol-quinones (e.g. dopachrome, aminochrome, and adrenochrome). Here we used electron paramagnetic resonance analysis to demonstrate that the phenomenon observed in CHO cells is also seen in human leukemic cells (K562 cells) that naturally express QR2. Moreover, by manipulating the level of QR2 in neuronal cells, including immortalized neuroblast cells and ex vivo neurons isolated from QR2 knockout animals, we showed that there is a direct relationship between QR2-mediated quinone reduction and ROS overproduction. Supporting this result, the withdraw of the QR2 co-factor (BNAH) or the addition of the specific QR2 inhibitor S29434 suppressed oxidative stress. Taken together, these data suggest that the overexpression of QR2 in brain cells in the presence of catechol quinones might lead to ROS-induced cell death via the rapid conversion of superoxide radicals into hydrogen peroxide and then into highly reactive hydroxyl radicals. Thus, QR2 may be implicated in the early stages of neurodegenerative disorders.

Response of Vibrio cholerae to the Catecholamine Hormones Epinephrine and Norepinephrine.

UNLABELLED: In Escherichia coli or Salmonella enterica, the stress-associated mammalian hormones epinephrine (E) and norepinephrine (NE) trigger a signaling cascade by interacting with the QseC sensor protein. Here we show that Vibrio cholerae, the causative agent of cholera, exhibits a specific response to E and NE. These catecholates (0.1 mM) enhanced the growth and swimming motility of V. cholerae strain O395 on soft agar in a medium containing calf serum, which simulated the environment within the host. During growth, the hormones were converted to degradation products, including adrenochrome formed by autooxidation with O2 or superoxide. In E. coli, the QseC sensor kinase, which detects the autoinducer AI-3, also senses E or NE. The genome of V. cholerae O395 comprises an open reading frame coding for a putative protein with 29% identity to E. coli QseC. Quantitative reverse transcriptase PCR (qRT-PCR) experiments revealed increased transcript levels of the qseC-like gene and of pomB, a gene encoding a structural component of the flagellar motor complex, under the influence of E or NE. Phentolamine blocks the response of E. coli QseC to E or NE. A V. cholerae mutant devoid of the qseC-like gene retained the phentolamine-sensitive motility in the presence of E, whereas NE-stimulated motility was no longer inhibited by phentolamine. Our study demonstrates that V. cholerae senses the stress hormones E and NE. A sensor related to the histidine kinase QseC from E. coli is identified and is proposed to participate in the sensing of NE. IMPORTANCE: Vibrio cholerae is a Gram-negative bacterium that may cause cholera, a severe illness with high mortality due to acute dehydration caused by diarrhea and vomiting. Pathogenic V. cholerae strains possess virulence factors like the cholera toxin (CTX) and the toxin-coregulated pilus (TCP) produced in response to signals provided by the host. In pathogenic enterobacteria, the stress-associated hormones epinephrine (E) and norepinephrine (NE) of the human host act as signal molecules for the production of virulence factors and promote bacterial growth by the sequestration of iron from the host. Here we show that V. cholerae, like some enterobacteria, benefits from these stress hormones and possesses a sensor to recognize them.

ANTIOXIDANT ACTIVITY OF ALKOXY DERIVATIVES OF (QUINOLINE-4-YLTHIO)CARBOXYLIC ACIDS.

A selection of potential bioactive molecules including alkoxy derivatives of (quinoline-4-ylthio)carboxylic acids using virtual screening has been carried out and their biological activity was determined. The studied substances proved to be low-toxic, biologically active compounds. It was established that 4-thio derivatives of quinoline exhibit pronounced antiradical, antioxidant-effects and can act as preventive antioxidants, radio and cytoprotectors.

The chemical interaction between adrenochrome, three different classes of antipsychotic drugs and metabolites of the kynurenine pathway.

Two kynurenine metabolites, 3-hydroxykynurenine and 3-hydroxyanthranilic acid, are known to inhibit melanin polymer formation in in vitro reactions catalyzed by tyrosinase. The present study expands that finding to include inhibition of chlorpromazine-stimulated melanin formation from the endogenous melanin precursor adrenochrome. Several kynurenine pathway metabolites tested had no measurable effect on the reaction: tryptophan, kynurenine, kynurenic acid, quinolinic acid and nicotinic acid. However, at a concentration of 0.5mM in a pH 7.4 reaction mix, 3-hydroxykynurenine exerted~72% inhibition on product formation and the same concentration of 3-hydroxyanthranilic acid caused complete inhibition. Two other classes of antipsychotic drugs were evaluated in this paradigm, represented by olanzapine and minocycline. Although the adrenochrome reaction of both drugs was strongly inhibited by 3-hydroxyanthranilic acid, 3-hydroxykynurenine inhibited product formation from only the minocycline reaction. The results are discussed in terms of the well-studied kynurenine pathway upregulation in psychotic disorders and how such upregulation may either influence the efficacy of antipsychotic drug treatment or relate to the mechanism of action of these drugs.

Validated spectrophotometric methods for simultaneous determination of troxerutin and carbazochrome in dosage form.

Four simple, accurate, sensitive and precise spectrophotometric methods were developed and validated for simultaneous determination of Troxerutin (TXN) and Carbazochrome (CZM) in their bulk powders, laboratory prepared mixtures and pharmaceutical dosage forms. Method A is first derivative spectrophotometry (D(1)) where TXN and CZM were determined at 294 and 483.5 nm, respectively. Method B is first derivative of ratio spectra (DD(1)) where the peak amplitude at 248 for TXN and 439 nm for CZM were used for their determination. Method C is ratio subtraction (RS); in which TXN was determined at its λmax (352 nm) in the presence of CZM which was determined by D(1) at 483.5 nm. While, method D is mean centering of the ratio spectra (MCR) in which the mean centered values at 300 nm and 340.0 nm were used for the two drugs in a respective order. The two compounds were simultaneously determined in the concentration ranges of 5.00-50.00 µg mL(-1) and 0.5-10.0 µg mL(-1) for TXN and CZM, respectively. The methods were validated according to the ICH guidelines and the results were statistically compared to the manufacturer's method.

A high-throughput adrenaline test for the exploration of the catalytic potential of halohydrin dehalogenases in epoxide ring-opening reactions.

The principle of the adrenaline test for enzymes is based on the quantification of periodate-sensitive reaction products with adrenaline to produce a chromogenic compound adrenochrome that can be easily detected. Here, a rapid whole-cell -based adrenaline assay for the activity measurement of halohydrin dehalogenases (HHDHs) in nucleophile-mediated epoxide ring-opening reactions is presented. The assay was validated using two types of model reactions (glycidol with nucleophiles and nitrite with epoxides). Moreover, the reliability of the assay was confirmed by gas chromatography analysis. Our results demonstrated that the developed assay is efficient in both library screening and the evaluation of catalytic diversity and specificity of HHDHs. Thus, the assay represents a valuable tool in the evolution of HHDHs for its industrial applications. Moreover, the adrenaline test exhibits a great potential for enzyme assay and could be easily adopted for other suitable enzymes.