The Hive > Serious Chemistry

Biosynth: Homebrewing Ephedrine

<< < (26/26)

Organikum:
Acetaldehyde serving as hydrogen-acceptor is told in several articles and for example in the Patent DD51651 (some of the examples in the patent are proven to be working well btw.).
Acetone works, as with acetaldehyde the amount which can be added is limited due to its toxity to the yeast (benzaldehyde the same). Formaldehyde cannot be used for this reason - its plain too toxic. Acetone has the advantage not to kill the yeast (except in VERY high concentrations but only to suppress fermentation. After some time the yeast will recover as the processes which transform the acetone to the alcohol (which is also toxic but much less) and the benzaldehyde to the l-PAC are independent from fermentation. The fermentation replentishes enzymes which are used up though.

A lower toxity substitute would be preferred of course. Any suggestions?

Nicodem:
Pyruvic acid maybe?
I'm not in the mood to go trough the whole thread, but aren't pyruvates used in some patents? Pyruvic acid is surely less toxic than acetone and acetaldehyde, besides being quite OTC and yielding only the edible lactic acid as a side product. Another less toxic ketone should be 2-butanone, but it is less soluble in water.

aia2:
Yes, one of the patents I liked used pyruvic acid and the yeast saccharomycae cervisiae (sp?).  Pyruvate is very OTC, too.

Organikum:
Look:



As you can see, the pyruvic acid is the reactand which produces l-PAC with benzaldehyde. If the pyruvic acid is added directly or if it is produced by the yeast from molasses or glucose doesnt make so much difference. If pyruvic acid or a salt of it is added directly non-fermenting conditions are used, if molasses or another source of fermentable sugars is used activly fermenting conditions have to be used. But this nothing to do at all with the question for a hydrogen acceptor, which plays solely the role to act as additional prey for the also yeast mediated aldehyde to alcohol reaction.
This for acetaldehyde is usually added which ends up as ethylalcohol.
Also ethylalcohol can be added to the biosynthesis to suppress ALL alcohol producing processes mediated by the yeast as far as possible. Yeast reduces them when a certain level of alcohol is reached in an attempt not to commit suicide.

I hope I could clear this up.
ORG

Navigation

[0] Message Index

[*] Previous page