Naming Organic Molecules (2) : Names Containing Japanese Words

Plants, animals and microorganisms produce a wide range of diverse chemical compounds. These chemicals of natural origin are generally known as natural products, and their extraction and isolation for medicinal purpose or as flavor ingredients have long been the subjects of active research. Once a natural product has been isolated from its source and its molecular structure has been determined, it needs a name. In many cases, a name is given to a molecule after the name (scientific name) of the organism from which it was isolated or the place where it was discovered. Chemical names also have appropriate suffix depending on the type of the compound. Japanese chemists have made significant contributions in this field, and there are a number of chemical names derived from Japanese words.

1. Names Derived from Plants
The research of aroma chemical compounds has been popular since the old days because it can lead to the production of highly valued flavor and fragrance ingredients. For example, hinokitiol and matsutakeol are the aroma components of hinoki (hinoki cypress) and matsutake (matsutake mushroom), respectively. Other examples include kainic acid, obtained from kaininsou (a type of red algae), and mugineic acid, extracted from the root of mugi or wheat (Figures 13-16).

Fig 13 hinokitiol (left) Fig 14 matsutakeol (right)

Fig 15 kainic acid (left) Fig 16 mugineic acid (right)

Shown in Figure 17, there is also a compound called okaramine, which was isolated from the bacteria grown on okara (soy pulp). This is a chemical name derived not directly from the plantfs name, but from the name of food made from plant. Okaramine is known to have an insecticidal property, perhaps showing an interesting use of this traditional Japanese food.

Fig 17 okaramine N

2.Names Derived from Places
There are a number of molecules named after Japanese places, such as nanaomycin, nikkomycin, and surugatoxin. Among the places, the southern islands of Okinawa are particularly rich in marine natural products thanks to the good ocean current and climate conditions. As a result, many marine natural products have names after the local places in Okinawa. Manzamines, discovered in the Cape Manza, and keramaphidines, discovered in the Kerama islands, drew chemistsf attention to become the popular targets for total synthesis because of their complex structures (Figure 18,.19).

Fig 18 manzamine A (left) Fig 19 keramaphidine (right)

There is even a compound named japanic acid, though it may not qualify for being derived from a gplace.h As shown in Figure.20, its structure consists of a linear chain of twenty one carbon atoms with carboxylic acid groups placed on both ends. This compound was isolated by the chemists in Germany during the early twentieth century, as a component of the valued Japan wax, which was obtained from Japanese sumac tree.

Fig 20 japanic acid

(3)Names Derived from People
There arenft actually a lot of examples in this category. There is a compound called okadaic acid, but this one was named after the Japanese marine sponge with a scientific name Halichondria okadai, from which it was first isolated (Figure 21). Scientific names are often made based on the person who made the discovery, so you could say that okadaic acid is indirectly derived from a personfs name ("Okada" is common family name in Japan). The complex skeleton makes this molecule another great target for total synthesis.

Fig 20 okadaic acid

It is not exactly a person, but there is a protein named shugoshin ("shugoshin" means guardian angel in Japanese). This protein plays a regulatory role during the cell division processes, and is present in all living organisms from yeast to humans. By continuously supporting cells to proliferate, shugoshin is a compound that is literally the gguardian angelh of life.
Letfs digress a little bit further for the interesting naming of proteins, which biochemists seem to be excellent at. In 2006, a protein was isolated from cat urine as its odor component, and was named cauxin, which stands for gcarboxyesterase like urinary excreted protein.h The name, of course, came from a Japanese word koukishin (curiosity), and has its origin in a proverb, gcuriosity kills even a cat.h
Sometimes creative naming ends in a disappointing result of not being accepted. In 2005, a new kind of gene having the function to inhibit the copy of information from DNA to RNA (transcription inhibitory factor) was discovered, and was given a surprising name POKEMON! The name stands for g POK erythroid myeloid ontogenic factor,h though it may sound a bit forcing.
A few months later, however, the name received a complaint from the copyright source, and the gene ended up receiving a new, less interesting name of Zbtb7. The problem might have been not just about copyright, but also the concern about the dangerous cancer-triggering gene getting the name of childrenfs hero. By the way, a gene named "sonic hedgehog" also exists, but this one seems to be enjoying international acceptance with no complaints.

Finally, let me introduce the names that are based on authentic Japanese culture. Cyclodextrin is a compound made up of six to eight D-glucose molecules linked to form a large ring. In 1991, Professor Mugio Nishizawa and his coworkers at Tokushima Bunri University synthesized an analog of cyclodextrin in which the D-glucose units were replaced by L-rhamnose. They named it cycloawaodorin ("Awaodori" is famous dance festival held in Tokushima city), causing laughter from the entire Japanese chemistry community (Figure 21). People may have only serious and stern images for the Japanese scientists, but some of them are in fact good humorists. After hearing about cycloawaodorin, the friend of mine at Hokkaido University was saying that he was going to follow it by making gsapporoyukimatsurin.h The updates? I have not heard from him yet ("Sapporo-yukimatsuri" is the snow festival held in Hokkaido).@

Fig 21 cycloawaodorin

There are many more of these interesting naming of chemicals, and you will see them in other parts of this book. By knowing these names, I hope that the readers can feel the chemistsf enthusiasm and attachment on the organic molecules they created. And most of all, I hope the readers understand that serious- and stern-looking chemists in white lab coats in fact truly enjoy what they do.