Amino acids in Chinese

When looking up the word for acid in Chinese, I came across the Chinese for the amino acids. Since I've previously written about DNA and the bases in Chinese, it seemed logical to compile a list of the Chinese amino acids. Working out the logic behind the Chinese words took quite a lot of research, but was very rewarding. Hopefully the effort will help me remember the words. You can download the list as a text file at the bottom of this post.

So firstly, amino acid, in Chinese is 氨基酸 (ānjīsuān), which breaks down to three characters meaning "ammonia base acid". All the amino acids have the suffix, 氨酸 (amino-acid) except asparagine and glutamine, which end with 酰胺 (amide). Aspargine begins with the same characters as aspartate, and glutamine the same as glutamate.

Below are tables of amino acids showing the characters that precede 氨酸 for the other 18 proteinogenic amino acids and their meanings. I've split the amino acids into groups based on what I think is the etymology.

Phonetic

These amino acids begin with a character which sounds like the English, so is probably phonetic.

Chemical

These amino acids begin with characters that describe the chemistry of the amino acid.

I was initially confused by alanine starting with 丙, which normally indicates the third in a series. However, it makes sense because it can also mean propyl (a three carbon chain), and the chemical name for alanine is 2-aminopropanoic acid. Phenylalanine is created by adding a benzene ring (phenyl group) onto the end of alanine, hence 苯丙. I've included isoleucine in this group because 异 means different, isoleucine is so called because it is an isomer of leucine (it's slightly confusing because actually iso- means same). Why leucine is 亮 is explained below.

Biological

These amino acids begin with characters that suggest a biological description origin.

I'm a little unsure about this category, but here's my reasoning.

Cysteine is from the Greek, kustis, meaning bladder because it was first isolated from urinary stones (not sure where the 半 come in).

Eggs are apparently a rich source of methionine, which might explain its Chinese name (the English is chemical: methyl+thio-).

Tryptophan fluoresces, which might explain why it begins with the character for colour (though tryptophan doesn't fluoresce in the visible spectrum). Incidentally, tryptophan is named after the enzyme trypsin, which was named from the Greek, tripsis, meaning friction because the protein was originally obtained by rubbing the pancreas with glycerine. Etymology is brilliant.

English Etymology

These amino acids begin with characters that have a link to the etymology of the English word (which is given in the final column). Note that while I say English etymology, most of the English words actually come from other European languages, especially German, and are based on Latin or Greek words. For me, this is the most interesting category because in researching it, I learnt the derivation of the English words.

Amino acids are often named after the sources from which they were first isolated.

• Asparagine was isolated from asparagus (the only etymology I knew previously; aspartate got its name from asparagine)
• Leucine was isolated from egg white
• Serine was isolated from silk
• Tyrosine was isolated from cheese
• Valine threw me for a while, but it turns out that the English comes from the herb, valerian, from which it was presumably first extracted. I was very pleased when I looked up valerian on the Chinese Wikipedia to find that it's 纈草 (knot grass), so valine is the "knot" amino acid.

I'm not sure why histidine is derived from the word for 'tissue', but it may be related to the role of the related chemical, histamine, which is involved in signalling between tissues.

Don't know

These are amino acids for which I can't see the logic of the Chinese and/or English name.

If I understood the etymology of the English names then I think I might understand the Chinese names. I would love to know who named the amino acids, both the in English and in Chinese.