as far as the link, i can send you my email to the organic chemist/ biochemist, there is no actual link.
Thew alpha isomer since its stronger and has a better stability is more likely to convert,
heres what i iasked.
the chemical
androst-4-ene-3,17-dione, 6-bromo-, (6 beta)
also known as 6bromoandrostenedione, has been used in breast cancer therapy in a study in 1972. now its recently been used in the supplement industry and has had conflicting views.
being that the target hormone for this compound is 6-bromotestosterone, there is both an alpha and beta ring. the beta ring being less stable then the alpha ring seems to be less potent then the alpha
its been said that because of the steric strain of the bromine in that position because of how bulky it is leads to the androst-4-ene-3,17-dione, 6-bromo-, (6 beta) not being able to convert into its target hormone which will upregulate the hypothalmic pituiatary testicular axis. but if it did convert to its target hormone it would have a negative effect on the HPTA.
how does the steric strain on this molecule block it from converting to its target hormone?
this is the response:
The answer to your question is "it's all about shape". The body's functions are controlled by enyzmes. The process by which the starting chemical is converted to the target hormone is done by enzymes. Enzymes can be particular in the way they allow some molecules into their active region. If the shape of the molecule isn't right - it won't fit and the enzyme can't do its job. So that bulky bromine causes the rings in the molecule to adopt a particular structure. It's all about energy - the lower energy a molecule has - the more stable it is. So the bromine forces this chemical to exist in a more stable structure with respect to the shape of the molecule that will fit into the enzyme and allow it to do its job. It's like a large weight pulling down on one side of the molecule (steric strain) and no matter what the molecule does - it can't lift that weight and allow it to change its shape so it can fit in the enzyme and convert into the target hormone.