Dilute Solution Viscometry Studies on a Therapeutic Mixture of Non-digestible Carbohydrates

摘要

Recent work has shown the beneficial effects of a proprietary mixture of three non-digestible carbohydrates:\udkonjac glucomannan, xanthan and alginate and these effects have been linked with a synergistic interaction observable\udwith analytical ultracentrifugation, rheological and NMR measurements. These observations have been supported by\udfundamental dilute solution viscosity studies. Preparations of konjac glucomannan, xanthan and alginate have been\udchecked with regards their molecular integrity (molar mass distribution) using a newly established method based on the\udanalytical ultracentrifuge. The intrinsic viscosity behaviour for each of the individual polysaccharides were estimated at\udlow ionic strength I (10-3M) and found to be (2090±120) ml/g, (4430±340) ml/g and (3460±330) ml/g for konjac\udglucomannan, xanthan and alginate respectively and at (10-1M) (2350±200) ml/g, (3370±310) ml/g and (1210±50) ml/g\udrespectively. The intrinsic viscosity [η] was then determined for a proprietary mixture of the three (known as “PGX®”) at\udboth ionic strengths and compared with the predicted values for a non-interacting mixture. In I=10-3 M solvent a\udsignificant difference was observed (3090+250) ml/g compared with the predicted value (2350+300) ml/g, although at\udhigher ionic strength the interaction appears to have gone: [η] = (1990+250) ml/g compared with the predicted value of\ud(2180+300) ml/g. This appears to reinforce the earlier observations that in PGX® there is a synergistic interaction which\udis ionic strength sensitive.