Abstract
The interactions of Mn(II) with phytic acid to form both soluble and insoluble complexes has been studied by calorimetric and EPR (electron paramagnetic resonance) techniques. The reaction to form soluble complexes (in the absence of precipitation) was examined over a range of mol ratios of Mn(II):phytic acid, from 1 to 6. Over this range of mol ratios the heats of reactions were endothermic. The amount of Mn(II) combined with the phytate was measured indirectly by an EPR procedure and the experimental heats of enthalpies were calculated. These enthalpies are a composite of a number of factors and varied to some extent dependent upon the Mn(II):phytate ratio. It is suggested that variations in the enthalpies could be a reflection of changes in the heats of ionization of the phytic acid and/or different binding sites with increasing Mn(II):phytate ratio. The heat of precipitation (which includes binding, solvation changes, etc.) of the insoluble Mn(II)-phytate complex was endothermic (22.4 kcal mol-1). This is similar in magnitude to the reported heats of precipitation reactions of Zn(II), Ca(II), Cu(II), Co(II), and Ni(II) with phytate. At approximately pH 6, measurements of the free Mn(II) concentration suggested that 5 mol Mn(II) binds per mol phytate.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
