Stuructures of new gibberellin glucosides in immature seeds of pharbitis nil

✍ Scribed by Takao Yokota; Nobutaka Takahashi; Noboru Murofushi; Saburo Tamura

• Publisher: Elsevier Science
• Year: 1969
• Tongue: French
• Weight: 209 KB
• Volume: 10
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)88090-4

✦ Synopsis

On the treatment with acetic anhydride-pyridine at room temparature the four glucosldes gave the ccrresponding acetates.

Chemical shifts in the NMR spectra of the glucosides and their acetates are summarized in Table. Esterification of a crystalline F-II tetraacetate (II), Cj~H40015H20**, m.p. 204-206', with diazomethane afforded an amorphous dimethyl ester (III), which shows a strong UV abscrption (Xm?x <'53 rnp, E 17,000) due to a heteroannular diene c system. No Y-lactonic band is observed in the IR spectrum of F-II. On acid hydrolysis, F-II yielded gibberic acid (4) and glucose exclusively. The above evidences indicate that F-II is composed of each one mole of gibberellenic acid (5) and glucose. The NMR spectrum of III not only supports the above aspect but also indicates the position of the glycosidic linkage. The C-2 proton doublet at t 5.75 (overlapped with C-6' protons) and the anomeric proton dcublet at t 5.35 (J-7.0 cps) characteristic of p-glucose show no differences in the chemical shifts frcm those of F-II. This indicates that the glucose moiety is attached to C-2. * The structural ol!~citi~!tion of F-VII is in progress.