92-35-3Relevant articles and documents
Green synthesis of gold nanoparticles using aqueous Aegle marmelos leaf extract and their application for thiamine detection
Rao, K. Jagajjanani,Paria, Santanu
, p. 28645 - 28652 (2014)
Nanoparticles of noble metals, especially gold nanoparticles are studied extensively because of their new and amazing properties. Among several synthesis techniques, green synthesis of nanoparticles is promising in recent years. In this study, we investigated the potential of Aegle marmelos leaf extract (LE) in reduction of HAuCl4 to form ~38.2 ± 10.5 nm spherical shape polyphenol capped gold nanoparticles. The stoichiometric proportion of the LE to HAuCl4 and the equilibrium time to complete the reduction process for the nanoparticle formation were also identified. The total reaction time was observed to be within ~30 min from the particle formation kinetics study. The as-synthesized gold nanoparticles capped with polyphenols of leaf extract were shown to be very effective for the detection of vitamin B or thiamine to a minimum concentration of ~0.5 μM.
Vitamin B1 sensor at neutral pH and improvement by cucurbit[7]uril
Prakash, Ramesh,Usha, Govindaraj,Karpagalakshmi, Karuppasamy,Ramalakshmi, Sundaram,Piramuthu, Lakshminarayanan,Yang, Cheng,Selvapalam, Narayanan
, p. 1503 - 1508 (2019)
Thiamine deficiency is an important issue for many diseases and thus a facile method of detection is clinically important to improve the health of humans. For that purpose, we have developed a new thiamine sensor using starch stabilized copper nanoparticles (CSNP) at neutral pH and also improved the sensitivity of the sensor using cucurbit[7]uril (CB[7]) through host-guest chemistry. Often thiamine is not detected directly, but through the oxidation of thiamine to thiochrome (TC); TC is a fluorescent emitting molecule, through which thiamine has been measured indirectly. Here, we have demonstrated a new approach for a thiamine sensor, based on the formation of TC by the addition of hydrogen peroxide and CSNP. Unlike the other reported thiamine sensors, our method works advantageously at physiological pH conditions (pH 7, 27 °C). Furthermore, addition of CB[7] to TC, increased the sensitivity of the sensor approximately one order magnitude, through encapsulation; which can be reversed upon addition of a stronger competitive guest such as adamantylamine to confirm the encapsulation of TC. Thus, this new thiamine sensor not only performed well under physiological pH conditions, but also improved the fluorescence of TC, when encapsulated by CB[7].
Reduction of cytochrome c in its reaction with thiamine and its structural analogs
Vovk,Babii,Murav'eva
, p. 1808 - 1812 (2007/10/03)
The kinetics of reduction of ferricytochrome c in its reaction with thiamine and its O-substituted structural analogs in phosphate buffer at pH 7.5-7.8 were studied. The reduction rate is proportional to the concentration of thiamine or its derivatives. The dependence of the reaction rate on the oxidant concentration is characterized by negative deviations from linearity. In oxidation with ferricytochrome c, the reactivity of thiamine consdierably exceeds the reactivity of thiamine diphosphate and thiamine monophosphate, and in oxidation with ferricyanide the reaction rate increases in the order thiamine monophosphate thiamine thiamine diphosphate. With O-(2-norbornoyl)thiamine, O-(2-adamantyl)acetylthiamine, O-benzoylthiamine, O-(4-nitrobenzoyl)thiamine, or O-(5-nitro-2-chlorobenzoyl)thiamine, the rate of ferricytochrome c reduction is higher than with thiamine. Presumably, the electron transfer to the heme group of the oxidant is preceded by formation of a complex of ferricytochrome c with the neutral tricyclic form of the substrate.