Isolation of gibberellins A26and A27and their glucosides from immature seeds ofPharbitis nil

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

• Publisher: Springer-Verlag
• Year: 1969
• Tongue: English
• Weight: 208 KB
• Volume: 87
• Category: Article
• ISSN: 0032-0935
• DOI: 10.1007/bf00386975

✦ Synopsis

Two new gibberellins, gibberellins Ae6 and Ae~ (GA2~ and GA2:), and their glucosides have been isolated from immature seeds of Japanese morning-glory (Pharbiti8 nil), together with GA s and its glucoside. GA~6, GA2~ and their glucosides showed only slight growth-promoting activities on seedlings of rice, dwarf maize and cucumber.

We have previously reported the isolation from immature seeds of Japanese morning-glory (Pharbitis nil C•oIs.) of gibberellin A20 and three gibberel]in (GA) glucosides, one of which was 2-O-fi-glucosyl-GA3, as well as the occurrence of GA 3 and GA 5 in this material (Mggorr:s~ et al., 1968 ; TA~U~A et al., 1968). In this paper we describe the isolation of two new GAs, GA2s and GA27, of GA s and of their glucosides of these three GAs from these seeds.

Immature seeds of morning-glory (108 kg), harvested in 1967, were extracted with methanol using a blender, and the methanol extract was separated into ethyl acetate-soluble and butanol-soluble acidic fractions by the usual method. The former fraction was purified through the procedure illustrated in Fig. 1 to yield two crystalline substances melting at 253.5--256.5 ~ (substance I) and 163--165 ~ (substance II, hydrate). GAs, obtained from the same fraction, was identified by comparison with an authentic sample (MAcMIL~A~ et al., 1962). The monomethyl esters of substances I and I I showed parent peaks of C20It2407 and C21H~s06, respectively, in high-resolution mass spectra. On the basis of infrared spectral data, both substances proved to be new GAs and were named GA26, C19H2207, and GA27, C~0H2606 .