xxxxx - 25-3-2006 at 09:21
vitamin c is a neccesary vitamin, however it has two disadvantages, first, the ester bond forming the five member ring is succeptable to hydrolysis by
heating in the presence of water in either acidic or basic conditions, which results in a non-cyclic molecule with zero percent ascorbic activity, and
secondly vitamin c is water soluable and rapidly excreted from the body. i was wondering if the oxygen linkage in the ester bond could be replaced
with a carbon atom with a ketonic oxygen to produce a non-hydrolysable five member ring to adress the first issue and replacing one of the
hydrogen-on-carbons with an n-amyl chain to make the molecule more fat soluable and less rapidly excreted to adress the second issue. these changes
should not affect the molecule's ability to convert dopamine to adrenaline, among other functions, as it is the ethylnic glycol portion of the
molecule that performs these functions.
JohnWW - 25-3-2006 at 11:05
Fat-soluble ascorbic acid derivatives with ascorbic biological activity have already been produced. These are long-chain-alcohol esters of ascorbic
acid, such as lauryl or oleyl or palmityl ascorbate, produced by esterification in the usual way. Also, I understand that it is alkaline conditions
that destroy the 5-membered internal ester ring in ascorbic acid with loss of ascorbic activity.
As for a polyalcohol cyclopentanone derivative, otherwise similar to ascorbic acid but having the ester oxygen linkange replaced by a carbon, it is
rather unlikely, because the mechanism of its biological activity may involve opening of the 5-membered ring. But if not, then the possibility may be
worth trying. The biological activity of the above fatty-acid esters of ascorbic acid, which appear to be chain rather than cyclic, may ndicate this.
Ascorbic acid can be commercially synthesized from common D-glucose (refined cane sugar) by hydrogenation with a Ni catalyst to D-glucitol, then
bacterial oxidation with acetobacter suboxydans to L-sorbose, and from that to ascorbic acid by way of a dehydration resulting in cyclization. This
would probably be much cheaper than trying to synthesize a cyclopentanone analog.