Changes in contents of gamma-glutamyl peptides and fructan during growth of Allium sativum.

Determination of gamma-glutamyl peptides, alliin, and fructan during growth of Allium sativum L. was carried out by HPLC. The contents of gamma-glutamyl peptides and alliin in garlic bulbs remarkably increased during one month before the garlic leaves withered.

Comparative investigation of vitamins and their analogues on terminal differentiation, from preadipocytes to adipocytes, of 3T3-L1 cells.

1. The effects of 20 kinds of vitamins or their analogues on the growth rate of preadipocytes and the terminal differentiation of preadipocytes to adipocytes was systematically compared in 3T3-L1 cells. 2. The addition of vitamin C markedly increased the growth rate of preadipocytes at over 50 microM. 3. The addition of vitamin K3 slowed down the growth rate at over 0.1 microM. 4. In water soluble vitamins and their analogues tested, the vitamin B6 group and vitamin C significantly stimulated the differentiation, and consequently increased the glycerophosphate dehydrogenase activity and triglyceride accumulation, to a concentration of over 10 microM. 5. Many fat soluble vitamins and their analogues (the vitamin A group, including beta-carotene, the vitamin D group, vitamin E and the vitamin K group) strongly inhibited the adipose conversion of 3T3-L1 cells at microM level.