My favorite vegetable is asparagus which is good because it’s very healthy. The only thing I would change about asparagus is the way that it makes the urine of the people who eat it stink. Curious about the phenomena, I found an article on Occurrence of S-methyl thioesters in urines of humans after they have eaten asparagus that had been published in an issue of Science in 1975. Its author said:
Gas chromatography-mass spectrometry was used to determine the odor-causing agent (or agents) present in the urines of humans after they have eaten asparagus. S-Methyl thioacrylate and S-methyl 3-(methylthio)thiopropionate were identified from methylene chloride extracts of such urines and appear to be the odor-causing compounds. Methanethiol, the previously reported odor-causing agent, was not detected in these methylene chloride extracts.
It certainly sounds like S-Methyl thioacrylate and S-methyl 3-(methylthio)thiopropionate are the culprits. I think the next step important step is to produce a sort of asparagus-urine-stink prophylactic. Kind of like Beano.
Did you know that the ability to smell S-methyl 3-(methylthio)thiopropionate is determined by a dominant gene. If you are homozygous for the recessive form, you cannot smell it at all. I recall (but my figure may not be accurate) that something like 20% of people can eat asparagus to their heart’s content and never fear the olfacto-urinary consequences.
But… did you know that the observation of the urine was determinant for a very important hypothesis in biology that claimed for the coding of enzimes (and hence proteins) by genes.
It was at the very first of the past century when two english doctors Garrod and Bateson observed a black coloured urine in a few children. The affected children can’t metabolize the acid 2,5-dihidroxyfenilacetic and its oxidation produces a black stain in urine and even in ears and nose. This illness is not lethal but you will always see a black colour in your toilet since you were born.
But the point is that these 2 doctors related the metobolic alteration with the heredity and genes. Although their work wasn’t widely recognize until the next 30 years, when Beadle and Tatoom did some experimental demonstration, this time with Drosophila melanogaster. (and were awarded with the Nobel)
But… did you know that the observation of the urine was determinant for a very important hypothesis in biology that claimed for the coding of enzimes (and hence proteins) by genes.
It was at the very first of the past century when two english doctors Garrod and Bateson observed a black coloured urine in a few children. The affected children can’t metabolize the acid 2,5-dihidroxyfenilacetic and its oxidation produces a black stain in urine and even in ears and nose. It is due to a genetic mutation that impairs the metabolic pathway of that compound, which is acumulated. This illness is not lethal but you will always see a black colour in your toilet since you were born.
But the point is that these 2 doctors related the metobolic alteration with the heredity and genes. Although their work wasn’t widely recognize until the next 30 years, when Beadle and Tatoom did some experimental demonstration, this time with Drosophila melanogaster. (and were awarded with the Nobel)
Wow! That’s great information Kiko and Benjamin(2).
I had heard that the ability to smell aspargus urine did vary from person to person. As in, you could take the urine from people who claimed their urine was unaffected by asparagus and give it to some people who were affected and they would be able to smell it!
Kiko, I am glad to hear that the attentin that I pay to my urine may be the first step on the way to a nobel prize. That is what you were implying, right?
A candidate gene has now been identified. Note the CC license.