Elymoclavine

Dehydration. Dehydration of hydroxy fatty acids is quite common. Other compounds undergo the same reaction, eg, elymoclavine [548-43-6] to agroclavine [548-42-5] chanoclavine [2390-99-0] and other compounds and <7j -terpin hydrate [2541-01-63] to a-terpineol [98-55-5] (19). 

There is some interesting new methodology that has been worked out in the course of these studies 73>76>. in general, stereospecificity relations of this sort are examined with the help of other enzyme reactions of known stereospecificity. When mevalonic acid (lactone form, 8 is fed to Claviceps, the 5-Hs atom is incorporated into the ergot alkaloids agroclavin 9a and elymoclavin 9b, whereas the 5Hr, atom is lost. 

Durch katalytische Hydrierung konnte Elymoclavin in Dihydro-d-lysergol-(I) und Dihydro-d-isolysergol-(I) iiberfuhrt werden 106). Somit war bewiesen, daB die Ringe C und D trans verkniipft sind und die riiumliche Anordnung am C-5 der der Lysergsaure entspricht. 

Zur Umwandlung der Clavine sind nicht nur Vertreter des Genus Claviceps befahigt, sondern auch eine Reilie anderer Pilze (Lit. s. 4). Auch in hdheren Pflanzen konntc die Hydroxylierung von Elymoclavin zu Penniclavin nachgewiesen werden (37). 

Schreier, K. Zur Stereochemie der Mutterkomalkaloide vom Agroclavin-und Elymoclavin-Typus. 46. Mitt, fiber Mutterkomalkaloide. Helv. chim. Acta 41, 1984 (1958). 

The Structure of Ergot Alkaloid, Elymoclavine. Bull, agric. chem. Soc. Japan 19, 94 (1955). 

The fructosylation of elymoclavine (9) by C. purpurea was described in [42] (Fig. 8). This reaction is mediated by the transfructosylating activity of p-fructofur-anosidase in sucrose-containing media. Beside mono- (10) and difructoside, higher fructosides (tri- and tetra-) (11) are also formed [43] (Fig. 9). 

Glycosylating Claviceps strains (mostly C. fusiformis) produce most elymoclavine in the form of p-fructofuranosides, which complicates the isolation of elymoclavine. The hydrolysis of fructosides by HCl is not suitable for a large scale process due to the aggressive nature of the acid solution and losses of elymoclavine. A more elegant method is a bioconversion employing the high invertase activity... 

For the preparation of p-o-galactopyranosyl (1 4)-2-acetamido-2-deoxy-p-D-gluco-pyranosyl-(l —>0)-elymoclavine (14) it was decided to extend previously prepared 2-acetamido-2-deoxy-p-D-glucopyranosyl-(1 0)-elymoclavine (15) using bovine p-l,4-galactosyltransferase. Uridine5 -diphosphogalactose (UDP-Gal) served as a substrate [48] (Fig. 11). 

Ergot Alkaloids.—4-(yy-Dimethylallyl)tryptophan (122) is the first intermediate beyond tryptophan in ergot alkaloid biosynthesis. Chanoclavine-I (127) is the first tricyclic base (cf. Vol. 10, p. 26, and ref. 2). Recently, (124 labels as shown) has been found to be a very efficient and intact precursor for elymoclavine (128).45 The high level of incorporation indicates that (123) is a probable intermediate situated between (122) and (127). The decarboxylation product (125) was not utilized for biosynthesis, so, although decarboxylation of (123) is required for the conversion of (123) into (127), either it is intimately associated with ring-closure or an imine that is related to (126) is involved. 

It has been found that elymoclavine (128) inhibits dimethylallyltryptophan synthetase, and the mechanism is one of feedback inhibition.46... 

In 1968 the existence of 3 in a Pennisetum type of ergot strain, producing mainly elymoclavine, could be established after addition of ethionine to the culture broth (6). 

When the Claviceps strain SD 58 was grown in a culture medium containing saccharose the slow formation of alkaloids containing polar groups was observed (15). These could not be extracted from the water phase in either alkaline or acid medium by the usual solvents. Finally, the principal alkaloid was isolated by ion exchange procedures and purified by subsequent chromatographic methods. The alkaloid was identified as elymoclavine-O-jS-D-fructofuranoside (12 ... 

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