Two molecules that share the same chemical formula
can produce significantly different effects in an
organism as a result of differences in their structure
and arrangement, called isomerism.
The natural Astaxanthin molecule has two
characteristic asymmetric carbon atoms that produce
three different stereoisomers: (3S,3’S), (3R,3’S), and
(3R,3’R). All have the same physical properties except
for the direction in which they rotate polarized light,
hence called optical isomers or enantiomers. Chemical
behavior of the enantiomers can be very different
when they react with biologically active molecules
that are also optical isomers.
Optical isomers exist in many biologically active
molecules of human body like enzymes, amino acids,
proteins, DNA and sugars, so Astaxanthin enantiomers
can produce quite different biological and physiological
effects when consumed by humans.
“Nature identical” claim of artificial astaxanthin
synthesized from petrochemicals is not true, as it
has different isomers that could act adversely upon
health. Its main composition are 3R, 3’S and 3R, 3’R
enantiomers, whose different physiological responses
have not been studied. Remember the sad story about
thalidomide optical isomers.
The 3S, 3’S optical isomer of astaxanthin has
always been in the human food chain and it is safe.
From microalgae phytoplankton through shrimp
zooplankton and fishes, this wonderful molecule
reaches food for human consumption. We do not
expect surprise effects from the 3S, 3’S isomer.