Physico-Chemical nanomaterials science

The group B vitamins (В1, В6, В12) as crystallization modifiers of calcium oxalate monohydrate
Taranets Y.V., Bezkrovnaya O.N., Pritula I.M.
Institute for Single Crystals, STC “Institute for Single Crystals“ NAS of Ukraine, Nauky Ave. 60, Kharkiv-61072, Ukraine.
E-mail: j.v.taranets@gmail.com

It is known that calcium oxalate monohydrate (COM) is a thermodynamically stable phase in the range of supersaturation characteristic of biological fluids. However, numerical studies have shown that the formation mechanism of this phase is complex and multistage, and its nature depends of the synthesis conditions and the presence of additives in solution.
This work is devoted to the study of COM nucleation kinetics and the influence of organic additives (B1, B6, B12 vitamins) on the nucleation processes, morphology and size of COM crystals. Crystallization of COM was performed under conditions close to physiological, as described earlier [1, 2].
It was found that B1 and B6 vitamins have an inhibitory effect on COM formation. The effect of inhibition increases in proportion to the rise of the concentration of vitamins in the solution. Addition of 40-50 mM B1 and B6 to the COM model system contribute to an increase in the nucleation time of pure COM in 70 times. Almost completely inhibits of COM crystals growth is observed, the degree of inhibition was over 95%. The nucleation time of COM with 70-100 µM B12 exceeds the one of pure COM by 2.5 times, and the degree of inhibition is 34.7%. It is shown that the addition of 50 mM B6 vitamin to COM model system resulted in the formation of single COM crystals with a size of 2 μm. That is by five times smaller than the sizes of pure COM crystals. The decrease in the size of the crystals is due to the formation of hydrogen bonds between the nitrogen atoms of pyridine ring of B6 molecule and protons on the {121} face of COM crystal.

1.	Kavanagh J.P., Jones L., Rao P.N. Calcium oxalate crystallization kinetics at different concentrations of human and artificial urine, with constant calcium to oxalate // Urol Res.-1999.-27.-P. 231-237.
2.	Taranets Y.V., Pritula I.М., Bezkrovnaya О.N., Mateychenko P.V., Sofronov D.S., Puzan A.N. Effect of Charge State of L-Aspartic and L-Arginine Amino Acids on Morphology of Calcium Oxalate Monohydrate // Cryst. Res.Technol.-2018.- 53 (4).- P.1700133 (7рр).