1. Photochemical studies of Nutraceuticals in the presence of Cyclodextrins.
Zlata Tofzikovskaya, Christine O’Connor and Mary McNamara.
School of Chemical and Pharmaceutical Sciences, Kevin Street, Materials Synthesis and Applications (MSA) Research Group, FOCAS Institute.
ABSTRACT
The photostability studies of Folic acid and Menadione Sodium Bisulfite, also known as vitamin K3, were carried out in their aqueous solutions at room temperature. Solutions of Folic acid ( 4.8 x 10-5 M) and Menadione Sodium Bisulfite (4.0 x 10-4 M) were exposed to ultraviolet radiation at a wavelength of 365 nm. During exposure absorbance of both solutions was measured using a Perkin Elmer Lamda 900 UV/VIS/NIR Spectrometer. During the stability tests it was noted that addition of β Cyclodextrin (1:1 ratio) to aqueous solutions containing the vitamin slowed down the photodegradation process. The unique shape of Cyclodextrins allows whole or partial inclusion of nutrients inside their cavity. The obtained results suggests that the physical mixture of β-Cyclodextrin with Folic acid or vitamin K3 enhances the photostability of the nutrients.
Scheme 1: The complex model of VK3-BCD
INTRODUCTION
The role of nutraceuticals in the diet is becoming more significant in recent years with the design of functional foods. This study looks at the enhancement of the photostability of the nutrient, Folic acid and Menadione Sodium Bisulfite, also known as vitamin K3.
Folic acid is a form of the water-soluble Vitamin B9.It occurs naturally in foods and can also be taken as supplements [1]. Folic acid is very important for all women who may become pregnant. Also recent studies suggested that folate may help in the prevention of cancer, as it is involved in the synthesis, repair, and functioning of DNA, and a deficiency of folate may result in damage to DNA that may lead to cancer [2].
Menadione Sodium Bisulfite also known as Vitamin K3
possesses the same action and is used for the same purpose as menadione or vitamin K; it differs, however, from menadione in being water-soluble. It is found chiefly in leafy green vegetables. Vitamin K is necessary for the synthesis of the proteins that help control bleeding (clotting factors) and thus for the normal clotting of blood. It is also needed for healthy bones and other tissues. Moreover recent research is quite clear it has an anti-cancer effect and is useful in the treatment of many different types of cancer including liver, colon, stomach, leukaemia, lung and breast.
Both vitamins are very sensitive to alkali medium and light. They undergo photodegradation in liquid media or in the solid state on exposure to light [2]. The nature and magnitude of photochemical reactions depends upon the intensities and wavelengths of light and control of these factors is critical in photostability studies of drugs and nutrients. Hence, the stability of folic acid and Vitamin K3 is of great concern to Nutritionists.
RESULTS
The effect of UV radiation on folic acid and vitamin K3 with and without cyclodextrin can be seen
from Figure 3-6. (What solute is used???)
Figure 3 Absorption spectra of vitamin K3 from min Figure 4 Absorption spectra of vitamin K3 with Cyclodextrin 0-240min
Figure 5 Absorption spectra of folic acid from min Figure 6 Absorption spectra of folic acid with Cyclodextrin min.
The emission spectra of folic acid can be seen in Figure 7. Fluorescence was measured during UV exposure. Excitation wavelength 280 nm.
Figure 7 Fluorescence emission spectra of Folic acid exposed to UV radiation.
Figure 1: Structure of Folic Acid
Figure 2: Structure of Vitamin K3
DISCUSSION
REFERENCES
A solution of vitamin k3 was exposed to UV radiation. All conditions were remained constant. The only variable was time of exposure. Figure 1 shows that as time of exposure increases, absorption at 265 nm decreases. It also seen
that the rate of decrease is faster after 40 minutes. this could suggests that 50% of vitamin degraded after 40
minutes. Stability study with cyclodextrin showed that rate of degradation is much slower under the same conditions.
This can be seen from Figure 2.Absorbance of vitamin K3 at 265 nm remains relatively constant.
Photostability test for folic acid showed similar results. Figure 4 shows absorbance spectra of folic acid solution with
cyclodextrin. In comparison to Figure 3, solution of folic acid, under the same conditions absorbance of folic acid at
280 nm remains relatively constant from min. Slight decrease can be observe after 180 min. Relativ
photostability of vitamin K3 and Folic acid in the present of Cyclodextrin can be explained by possible guest –host
Inclusion[3]. Results suggests that studied vitamins can be protected from photodegradation using cyclodextrins.
Inclusion and therefore photostability depend on structure and size of the molecule. (WILL NEED TO RE_WORD SOME OF THIS)
Gregory, J.F Bio-availability of folate. Eur. J. Clin. Nutr., 51:
Arnfinn Engeset Steindal, Alina Carmen Porojnicu and, Asta Juzeniene, Ultraviolet photodegradation of folic acid, J. Photochem and Photobio. 80, 1 (2005).
M.R. Wilson, F.T. Wals and S.K. Gee. Tetrahedron Lett. 21 (1980), pp. 3459–3462.
ACKNOWLEDGMENTS
CONCLUSION
FOCAS Institute, Dublin Institute of Technology
and the School of Chemical and Pharmaceutical Sciences,
DIT, Kevin St., Dublin, Ireland.
Preliminary investigations suggest that the formation of inclusion complexes with cyclodextrins can
enhance the photostability of nutraceuticals such as vitamin K3 and Folic acid. Addition of cyclodextrin increases the stability of some vitamins in aqueous media??. Moreover previous studies showed that inclusion complexes increase solubility and bioavailability in aqueous media. (REFERENCE)