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Graphite carbon nitride (g-C 3 N 4 ) is a two-dimensional nano-sheet with electronic properties, which shows unique characteristics with high chemical and thermal stability in its structure. The functionalization of these compounds through covalent bonding is an important step towards significantly improving their properties and capabilities. To achieve this goal, a novel strategy for the covalent functionalization of Fe 3 O 4 @g-C 3 N 4 with thiamine hydrochloride (vitamin B1) via cyanuric chloride (TCT), which is a divalent covalent linker, was presented. The efficiency of Fe 3 O 4 @gC 3 N 4 @Thiamine as a heterogeneous organic catalyst in the synthesis of spirooxindole-pyran derivatives and 2-amino-4 H -pyran under solvent-free conditions was evaluated and the yields of high-purity products were presented. In addition, easy recycling and reuse for seven consecutive cycles without significant reduction in catalytic activity are other features of this catalyst. Moreover, the performance of the prepared sorbent in the microextraction technique (herein, magnetic solid phase extraction) was studied. The tebuconazole was selected as the target analyte. The target analyte was extracted and determined by HPLC–UV. Under the optimum condition, the linear range of the method (LDR) was estimated in the range of 0.2–100 μg L −1 (the coefficient of determination of 0.9962 for tebuconazole). The detection limit (LOD) of the method for tebuconazole was calculated to be 0.05 µg L −1 . The limit of quantification (LOQ) of the method was also estimated to be 0.16 µg L −1 . In order to check the precision of the proposed method, the intra-day and inter-day relative standard deviations (RSD%) were calculated, which were in the range of 1.5- 2.8%. The method was used for the successful extraction and determination of tebuconazole in tomato, cucumber, and carrot samples.

The treatment of several pediatric metabolic diseases involves vitamins supplementation. Among these, thiamine, riboflavin, pyridoxine and biotin can be prescribed and compounded as hard gelatin capsules. In compounding practice, a medication can be done extemporaneously, leading to a risk of error. However, a medication can also be done in advance, analytically controlled and stored. Such practice reduce the risk of error and decrease the cost, but also imposes the realization of stability studies to establish beyond-use-dates. Thiamine hydrochloride, riboflavin, pyridoxine hydrochloride, and biotin hard gelatin capsules chromatographic and microbiological methods were both validated and used to perform stability studies. Thiamine hydrochloride 50 mg hard gelatin capsules with microcrystalline cellulose and silica as excipients are stable for 6 months when stored at 25 ° C/ 60% RH protected from light. Riboflavin 50 mg with microcrystalline cellulose, pyridoxine hydrochloride 50 mg with microcrystalline cellulose and biotin 40 mg with microcrystalline cellulose/silica are stable for one year when stored at 25 ° C/ 60% RH protected from light. These results allow the compounding in advance of batches of 300 capsules controlled, stored, and quickly dispensed in case of an emergency, such decreasing the risk of error and/or iatrogenic event.

The temperature difference can lead to different changes in thermodynamic and physico-chemical properties of solutions. The irretrievable thermodynamics offers interface conditions that yield chemical energy change at phase interfaces. The study of change in thermodynamic properties such as apparent molar volume, V 2,ϕ , limiting apparent molar volume, V 2 , ϕ 0 volume transfer properties, Δ t r V 2 , ϕ 0 and Hepler’s constant have been done by changing the temperature of solutions of L-isoleucine in aqueous thiamine hydrochloride from 298.15K to 318.15K at constant pressure. For this study, the density ( ρ ) of the solutions have been measured experimentally at five different temperatures. The effect of temperature difference and hence the mass-transfer in solutions creates some changes in the electrostriction among the solute and solvents. Thus, significant changes like structure-making and structure-breaking as well as intermolecular interactions changes take place in the solutions. In this paper we found that the difference in temperature impacted a much on the volumetric properties and the apparent molar volume as well as limiting apparent molar volume rise with the increase of temperature. The negative values of Hepler’s constant refers the solute is a structure breaker and the positive values of apparent molar volume as well as limiting apparent molar volume indicate the presence of strong solute-solvent interactions in the solution. This is loosened at higher temperatures.

From late 2014 multiple atolls in Kiribati reported an unusual and sometimes fatal illness. We conducted an investigation to identify the etiology of the outbreak on the most severely affected atoll, Kuria, and identified thiamine deficiency disease as the cause. Thiamine deficiency disease has not been reported in the Pacific islands for >5 decades. We present the epidemiological, clinical, and laboratory findings of the investigation. We initially conducted detailed interviews and examinations on previously identified cases to characterize the unknown illness and develop a case definition. Active and passive surveillance was then conducted to identify additional cases. A questionnaire to identify potential risk factors and blood samples to assay biochemical indices were collected from cases and asymptomatic controls. Thiamine hydrochloride treatment was implemented and the response to treatment was systematically monitored using a five-point visual analogue scale and by assessing resolution of previously abnormal neurological examination findings. Risk factors and biochemical results were assessed by univariate and multivariate analyses. 69 cases were identified on Kuria (7% attack rate) including 34 confirmed and 35 unconfirmed. Most were adults (median age 28 years [range 0-62]) and 83% were male. Seven adult males and two infants died (13% case fatality rate). Resolution of objective clinical signs (78%) or symptoms (94%) were identified within one week of starting treatment. Risk factors included having a friend with thiamine deficiency disease and drinking kava; drinking yeast alcohol reduced the risk of disease. Higher chromium (p<0·001) but not thiamine deficiency (p = 0·66) or other biochemical indices were associated with disease by univariate analyses. Chromium (p<0·001) and thiamine deficiency (p = 0·02) were associated with disease by multivariate analysis. An outbreak of thiamine deficiency disease (beriberi) in Kiribati signals the re-emergence of a classic nutritional disease in the Pacific islands after five decades. Although treatment is safe and effective, the underlying reason for the re-emergence remains unknown. Chromium was highly and positively correlated with disease in this study raising questions about the potential role of factors other than thiamine in the biochemistry and pathophysiology of clinical disease.

This study presents a sustainable one-pot synthesis of novel pyrazolyl phosphonate derivatives via a three-component reaction using 3-methyl-1-phenyl-2-pyrazoline-5-one, aryl aldehydes and dibutyl phosphite, catalyzed by thiamine hydrochloride under solvent-free conditions. Two of these synthetic chemicals were chosen for in-depth density functional theory analysis due to their electron-donating (methoxy) and electron-withdrawing (nitro) groups, providing insights into their electronic properties, reactivity and stability through highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap calculations. Strong interactions with the active sites of acetylcholinesterase (AChE) were found by molecular docking experiments. The compounds also exhibited potent anti-inflammatory and antioxidant activities in biological assays. Additionally, absorption, distribution, metabolism, excretion and toxicity profiling suggested favourable bioavailability and low toxicity, demonstrating their medicinal potential in the creation of new drugs. Graphical abstract

A rapid and environmentally friendly method was developed for synthesizing 1,5-benzodiazepine derivatives, utilizing catalytic quantities of thiamine hydrochloride in an aqueous media. The desired compounds were acquired with notable yields by amalgamating variously substituted aryl aldehydes with dimedone and o-phenylene diamine using thiamine hydrochloride as a catalyst. This approach presents several benefits, including swift reaction kinetics, utilization of eco-friendly solvents, straightforward workup procedures and a facile purification process, ensuring energy conservation and extensive compatibility with diverse substrates. Graphical Abstract Synopsis . A green, rapid, and efficient method for synthesizing 1,5-benzodiazepine derivatives was developed using thiamine hydrochloride as a catalyst in water. This environmentally benign approach achieved excellent yields, compatibility with diverse substrates, and minimal reaction times, highlighting its potential as a sustainable alternative in heterocyclic compound synthesis.

Phenolic compounds and thiamine may serve as therapies against oxidative stress-related neurodegenerative diseases. However, it is important to note that these components show high instability under changing conditions. The study’s aim was to determine the impact of the thiamine concentration (hydrochloride—TH and pyrophosphate—TP; in the range 0.02 to 20 mg/100 g on the indices of the chelating properties and reducing power, and free radicals scavenging indices of EGCG, EGC, ECG and caffeine added from 0.04 to 6.0 mg/100 g. Our research confirmed that higher concentrations of TH and TP can exhibit significant activity against the test antioxidant indices of all components. When above 5.0 mg/100 g of thiamine was used, the radical scavenging abilities of the compound decreased in the following order: EGCG > ECG > EGC > caffeine. The highest correlation was found for the concentration of thiamine pyrophosphate to 20.0 mg/100 g and EGCG. Knowledge of the impact of factors associated with the concentration of both EGCG, EGC, ECG or caffeine and thiamine on their activity could carry weight in regulating the quality supplemented foods, especially of nutrition support for people of all ages were oral, enteral tube feeding and parenteral nutrition).

The free exopolysaccharide (f-EPS) produced by Streptococcus thermophilus is a natural texture modifier with health-promoting properties and has thus become one of the most interesting metabolites for researchers. The present work aimed to further understand the nutritional requirements for the growth of and the f-EPS production by S. thermophilus. The types and concentrations of compounds in the complete chemically defined medium were changed in turn to evaluate the effects of single nutrients on the growth of and f-EPS production by S. thermophilus 937. The results showed that cysteine, glutamine, histidine, methionine, tryptophan, tyrosine, leucine, isoleucine, and valine played an important role in maintaining the rapid and stable growth of S. thermophilus 937. S. thermophilus 937 also required calcium pantothenate, niacin, pyridoxine, riboflavin, and thiamine hydrochloride as essential nutrients for growth. Increases in the concentrations of lactose, glutamate, histidine, or isoleucine significantly increased the production of free exopolysaccharide by S. thermophilus 937, and when the lactose concentration increased to 20 g·L−1 and the concentration of the three-amino-acid combination increased to 15 mM, the f-EPS yield increased to a maximum of 35.34 μg·mL−1. This finding indicated that lactose and the 3 amino acids exert synergistic effects on the promotion of f-EPS production. In addition, lactose and the three amino acids have strain specific promoting effects on f-EPS production by S. thermophilus. This study provides a further understanding of the effects of nutrients on the biosynthesis of f-EPS by S. thermophilus.

The Thiamine Transporter 2 (THTR2) encoded by SLC19A3 plays an ill-defined role in the maintenance of tissue thiamine, thiamine monophosphate, and thiamine diphosphate (TDP) levels. To evaluate the impact of THTR2 on tissue thiamine status and metabolism, we expressed the human SLC19A3 transgene in the intestine of total body Slc19a3 knockout (KO) mice. Male and female wildtype (WT) and transgenic (TG) mice were fed either 17 mg/kg (1×) or 85 mg/kg (5×) thiamine hydrochloride diet, while KOs were only fed the 5× diet. Thiamine vitamers in plasma, red blood cells, duodenum, brain, liver, kidney, heart, and adipose tissue were measured. Untargeted metabolomics were performed on the brain tissues of groups with equivalent plasma thiamine. KO mice had ~two- and ~three-fold lower plasma and brain thiamine levels than WT on the 5× diet. Circulating vitamers were sensitive to diet and equivalent in TG and WT mice. However, TG had 60% lower thiamine but normal brain TDP levels regardless of diet, with subtle differences in the heart and liver. The loss of THTR2 reduced levels of nucleic acid and amino acid derivatives in the brain. Therefore, mutation or inhibition of THTR2 may alter the brain metabolome and reduce the thiamine reservoir for TDP biosynthesis.

Thiamine hydrochloride (THCL), also known as vitamin B1, is an active pharmaceutical ingredient (API), present on the list of essential medicines developed by the WHO, which proves its importance for public health. THCL is highly hygroscopic and can occur in the form of hydrates with varying degrees of hydration, depending on the air humidity. Although experimental characterization of the THCL hydrates has been described in the literature, the questions raised in previously published works suggest that additional research and in-depth analysis of THCL dehydration behavior are still needed. Therefore, the main aim of this study was to characterize, by means of quantum chemical calculations, the behavior of thiamine hydrates and explain the previously obtained results, including changes in the NMR spectra, at the molecular level. To achieve this goal, a series of DFT (CASTEP) and DFTB (DFTB+) calculations under periodic boundary conditions have been performed, including molecular dynamics simulations and GIPAW NMR calculations. The obtained results explain the differences in the relative stability of the studied forms and changes in the spectra observed for the samples of various degrees of hydration. This work highlights the application of periodic DFT calculations in the analysis of various solid forms of APIs.