Influence of food intake on the enantiomeric composition of urinary salsolinol in man.

Salsolinol is present in human fluids and tissues as well as in foods and beverages. It was shown previously that the R enantiomer of salsolinol predominates in human urine, whereas the S enantiomer predominates in Port wine. An R/S ratio very near to 1 was found in dried banana, a food particularly rich in salsolinol. In this study 100 g of dried banana were administered to 6 healthy subjects. The urinary excretion of the R and S enantiomers of salsolinol was measured 24h before and 24h after banana intake, each time in two fractions. Whereas the S enantiomer was present only in the fraction 5 p.m.-9 a.m. and only in 3 out of the 6 subjects before banana intake, this enantiomer was found in the two intervals 9 a.m.-5 p.m. and 5 p.m.-9 a.m. in all the subjects after banana intake. The presence of the S enantiomer in urine in 3 subjects before dried banana might be related to alcohol intake. The amount of R + S salsolinol eliminated in the 24h urine was found to represent 0.75% of the total dose administered. In conclusion a normal diet should have a negligible influence on urinary salsolinol concentrations, with, perhaps, the exception of alcohol; interestingly the R enantiomer might represent endogenous salsolinol.