Posted by Larry Hoover on February 1, 2003, at 7:21:20
In reply to Re: dl, l ?, posted by michael73 on January 31, 2003, at 19:43:21
> What do the prefixes dl,l etc signify on some supplements? Is there more than one version of phenylalanine? Michael73
The d- and l- prefixes stand for dextro- and levo-, meaning right and left, respectively. Some molecules come in three-dimensionally distinct forms, just as a right glove and left glove are identical in all respects, but for their "handedness". In nature, that handedness is really important, and most higher life forms have evolved to use the l- form of amino acids exclusively. So, natural-source amino acids will be the l- version, unless they are from fermentation, where some d- forms are present (just as an example, about 10% of the aminos in beer are d- versions). When humans synthesize amino acids in reaction vessels, there is an equal probability that the l- and d- structures will be created. So man-made aminos are designated d-,l- (which means they are roughly 50% d- and 50% l-). D-,l-phenylalanine (or DLPA) is one example of this.
Lar
poster:Larry Hoover
thread:138568
URL: http://www.dr-bob.org/babble/20030130/msgs/138708.html