Biogenesis of Ascorbigen, 3-Indolylacetonitrile and Indole-3-carboxylic Acid from D,L-Tryptophan-3-14C in Brassica oleracea L.

Indole Auxins

“…The biogenesis of radioactive ascorbigen from tryptophan-3-14C in Savoy cabbage [Kutacek et at. (108)] has confirmed the earlier work, which revealed ascorbigen formation after tryptophan was injected into the bulb of kohlrabi (110). Further experiments will perhaps decide the relative im portance of the pathways via IPyA and indole-3-pyruvaldehyde.…”

“…FAWCETT XV. The production of radioactive IAN from 14C-tryptophan in Savoy cabbage (108), watermelon (49) , and oat tissue (123) could be via this al ternative route, but since radioactive IPyA was also detected in these studies the other described pathways to IAN may be involved.…”

“…Thus, the level of ascorbigen and IAN was higher in Brassica oleracea seedlings grown in the light than in plants grown in the dark, but the latter contained higher levels of tryptophan [Kutacek et al (107)]. This relationship changed very little over several days, and in view of the biosynthesis of ascorbigen from tryptophan [Kutacek et al (108)], it would be of interest to know whether the balance of these important pre cursors in other plants is changed with the lighting conditions.…”

“…The level of free tryptophan was correlated with free IAA during the development of maize seedlings [Yamaki & Nakamura (226)] and strawberry fruits [Nitsch & Wetmore (140)], but in tobacco styles and ovaries a de crease in free tryptophan occurred when the auxin level was increasing [Lund (126)]. In watermelon tissue the main pathway for the conversion of tryptophan-2-14C to IAA seemed to be through IPyA, based on the RF and radioactivity of the IPyA relative to IAA [Dannenburg & Liverman (49)] ; although this evidence was considered to be unconvincing [Kaper & Veld stra (97)], the pathway via IPyA was also found important in oat (123), pineapple (76), maize (226), and cabbage (108). The in vitro study of IAA formation from tryptophan by Agrobacterum tumefaciens (97) revealed a characteristic pattern of metabolites on the chromatogram, similar to that obtained from IPyA decomposition.…”

Ascorbigen – Occurrence, Synthesis, and Analytics

“…Later, ascorbigen was also found in other vegetables, such as Brussel sprouts, cauliflower, and broccoli, and seems to be a characteristic key compound in cruciferous greens [11][12][13][14][15]. 1) [17][18][19][20]. During the breakdown of glucobrassicin upon plant tissue disruption, ascorbigen (1) is formed.…”