The ‘Awa (Kava) plant has a lot of different active ingredients called "Kavalactones" There are 6 major and minor Kavalactones that give us the psychoactive effect, they are—
Desmethoxyyangonin = 1
Dihydrokavain = 2
Yangonin = 3
Kavain = 4
Dihy dromethysticin = 5
Methysticin = 6
The numbers were given to each kavalactone by Dr. V. Lebot so that we can see what is called the chemotype, by knowing the chemotype we can tell if it will be a real good Awa (Kava) or one that may be too strong, for example, if you have a ‘Awa that has a chemotype that starts with these 3 numbers—4 2 6, that is a good Awa, we know this because of the rate the kavalactones are absorbed into our blood stream and the way certain Kavalactones will react, some will cause a stomach discomfort like the kavalactones dihydromethysticin and dihydrokavain, if your kava has a lot of these kavalactones then you might get some stomach discomfort. Thankfully most ‘Awa (Kava) does not cause the stomach discomfort.

Of these 6 kavalactones they are broken down into 2 groups, 1-major kavalactones and the other is minor kavalactones and just as a note, "Lebot and Levesque demonstrated that the major kavalactones account for about 96% of the lipid extract, but the minor kavalactones are needed too, Kavalactones have a big synergy effect, to give you an idea, I had a Mahakea plant that I had tested at 11.2 percent, this test was done with the root and the corm of the ‘Awa plant, the root was the strongest and then the corm but since it was done separately I could see the chemotype for each one and by mixing different proportions of the root and the corm I could change the chemotype, and to a certain degree the effect, if I mixed it with a different ‘Awa of a different chemotype I could calculate the chemotype of the mix, mixing different ‘Awa is good and different than just one ‘Awa by it’s self, but being a ‘Awa farmer for over 25 years I have had the chance to drink all the varieties that are grown here in Hawaii and each by itself has it’s own qualities and effects all by themselves. Mixing is always up to the drinker. 🙂
"Kavalactones" =
These are the active ingredients in the Awa, it is what gives us the psychoactive effect. There are 6 main Kavalactones and they are— Desmethoxyyangonin = 1 Dihydrokavain = 2 Yangonin = 3 Kavain = 4 Dihydromethysticin = 5 Methysticin = 6 Every Awa plant has these Kavalactones and each plant has them in varying quantities, that is why Dr. V Lebot gave them each a number, so with the numbers a "chemotype" can be created, my using HPLC chromatography we can tell how many of each Kavalactones there are in a certain Awa and the kavalactone that is the highest, that number will come in the first position of the chemotype, for example most Hawaiian Awa’s have a chemotype of 462351, since 4 is the first number and we know that 4 has been assigned to Kavain, we know that that Awa is highest in Kavain and that just so happens to be one of the most sought after Kavalactones.

Taken from GHK site