When we examined the TBECH
diastereomer binding activities, we found that 50:50 TBECH-[gamma][delta] binds to the AR with 22% of DHT's binding affinity, whereas for 50:50 TBECH-[alpha][beta] we found a relative binding affinity (RBA) of 6%.
Determination of flame retardant hexabromocyclododecane
diastereomers in textiles.
This difference in affinity may have been attributable to a stereoselectivity bias from the FBP toward the unnatural
diastereomer of the racemic 5mTHF.
The stability of the derivatives was tested by regression analysis in which the absolute peak areas of each
diastereomer of AM and MA at each concentration were plotted vs injection time.
A solution of the
diastereomer (6.81 g, 0.005 M) in a minimum amount of water was added to potassium chloride (0.52 g, 0.005 M) with vigorous stirring.
Residue was purified by column chromatography (silica gel, EtOAc/C[H.sub.3]OH 1: 4) affording product 2i (one
diastereomer) as a white solid (40 mg, 31%; mp > 240[degrees]C).
The major
diastereomer 7a upon treatment with Bocanhydride and TEA in DCM using catalytic amount of DMAP at 0[degrees]C to rt produced carbamate 8 with 79% yield.
It is known that silymarin elicited partial ER activation and silybin B were probably responsible for a majority of the weak ER-mediated activities of silymarin, whereas, its
diastereomer, silybin A, was found to be inactive [173].
Covaci, "Causes of variability in concentrations and
diastereomer patterns of hexabromocyclododecanes in indoor dust," Environment International, vol.
Spatial
diastereomer patterns of hexabromocyclododecane (HBCD) in a Norwegian fjord.
Of all the forms, the studies of its threo
diastereomer revealed that d-threo isomer has been found to be more active and also showed significant metabolic difference than l-threo enantiomer.
Since this reaction introduces two chiral carbons into the product, the cis alkenes are known to form a racemic mixture, and the trans isomer forms a stereospecific meso
diastereomer. According to the literature (Mathai et al., 1956), addition of bromine to maleic acid in chloroform solvent occurs in the dark at room temperature but takes several days.