Antiallergic Activity of 3-O-Dodecyl-l-ascorbic Acid.

2-O-Alkyl-l-ascorbic acids and 3-O-alkyl-l-ascorbic acids were synthesized, and their degranulation inhibitory activities were evaluated. Among ascorbic acid derivatives with butyl, octyl, dodecyl, hexadecyl, and octadecyl groups introduced at the C-2 or C-3 positions, an AA derivative with a dodecyl group introduced at the C-3 position, 3-O-dodecyl-l-ascorbic acid (compound 8), showed the strongest inhibitory activity against antigen-stimulated degranulation. Compound 8 also inhibited calcium ionophore-stimulated degranulation. Compound 11, in which the hydroxyl group at the C-6 position of compound 8 was substituted with an amino group, and compound 12, in which the dodecyloxy group at the C-3 position of compound 8 was exchanged with a dodecylamino group, were synthesized, and these derivatives showed weaker inhibitory activity against antigen-stimulated degranulation than that of compound 8. In addition, orally administered compound 8 inhibited passive cutaneous anaphylaxis reactions in mice with a potency equal to that of oxatomide, an antiallergic agent. These results suggest that compound 8 may be a candidate for antiallergic treatment.

A simple efficient synthesis and biological evaluation of 3-O-ethylascorbic acid.

A single-step synthesis of 3-O-ethyl-l-ascorbic acid was performed without the induction of protecting groups. Sodium l-ascorbate reacted with ethyl bromide in DMSO to give 3-O-ethylascorbic acid in a yield of 51.0%. 3-O-Ethylascorbic acid enhanced dibutyryl cyclic AMP-induced neurite outgrowth in PC12 cells.