Hydroxydehydrostevic acid ("steviol", IV). (a) From stevioside. In the enzymatic hydrolysis of stevioside the directions of Bride1 and Lavieille (1)
were modified as follows. A solution of 2.0 g. of stevioside in 250 ml. of water (boiled previously) to which had been added 5 ml. of freshly prepared
("enzyme-juice" and 10 ml. of toluene, was incubated at 34° for 6 days. The pH in different experiments varied from 4.8 to 5.3. The slightly colored,
and clear solution became opaque and turbid after about 10 hrs., and a fine white apparently amorphous precipitate containing crystalline material
appeared. The reaction mixture was exhaustively extracted with ether, and the residue of the washed and dried ethereal solution was recrystallized
from ethanol-water or methanol and gave 0.43 g. (54%) of needles melting at 206-208°, [elD -74.0° (ethanol). Another crystallization from methanol
gave 0.35 g.(44%) of needles melting at 212-213° with a change above 180’ to rhomboid plates, [ala -93.6° (ethanol), lit. (1) m.p. 215°, [.ID
-94.7° (ethanol). The analytical sample was dried at 100° in a high vacuum.
Anal. Calc’d for C20HS0O3: C, 75.43; H, 9.50; Active H, 2.00. Found: C, 75.48; H, 9.60; Active H, 2.13. |
