Chemistry of Gibberellins From Floweririg Plants 

 Table 1 . Paper chromatography of the gibberellins. 



477 



* Kga = Migration relative to A3. 



t Solvent systems: A = Upper phase of a mixture of n- 

 butyl alcohol: 1. 5 JV ammonium hydroxide (3:1). B = Upper 

 phase of a mixture of n-amylalcohol:pyridine:water (35:35:30). 

 C = Upper phase of a mixture of benzene: acetic acid (gla- 

 cial) :water (4:1:2) (1). 



X Migrated off the end of the chromatogram under the con- 

 ditions employed. 



bean factor II. Theoretical neutral equivalents for Ai and A3 are 

 348 and 346. Thus, bean factors I and II are clearly shown to have 

 an acidic functional group with a neutral equivalent close to those 

 of the fungal gibberellins. 



Paper Chromatography 



It can be seen by reference to Table 1 that Aj, A2, and A3 migrate 

 to approximately the same extent on paper chromatograms in the 

 three solvent systems shown, whereas A4 moves considerably further 

 from the origin. Bean factor I behaves as Ai in these systems. Bean 

 factor II is closer to A4 in its behavior, though not identical with it. 

 Since Aj, Ao, and A3 each have two alcoholic hydroxyl groups and A4 

 has only one, these results might be interpreted as presumptive evi- 

 dence for the presence of one alcoholic hydroxyl group in bean fac- 

 tor II. 



Determination of Ethylenic Double Bonds 



A preliminary microhydrogenation experiment suggested that 

 bean factor II has two ethylenic double bonds per acid equivalent as 

 does A3 and bean factor I has one as does Aj. 



Confirmation of these conclusions came from the application of 

 a microtechnique for the determination of such double bonds. A 

 sample of 20 to 40 micrograms of gibberellin of known weight was 

 dissolved in 3.5 ml. of freshly prepared potassium permanganate solu- 

 tion (3 mg. per 100 ml. solution in distilled water). After 15 min. the 

 absorbancy of the solution was determined at 415 m/x in a Beckman 



