8 Essays in Biochemistry 



as judged by spectrophotometric evidence, but the chemistry of these 

 compounds has not yet been investigated. 



Agrocybin, isolated from culture liquids of Agrocybe dura, was char- 

 acterized as XI. 33 



HOH 2 C— C=C— feC— C=C— CONH 2 xi 



This compound bears interesting relationships both to biformyne 2 and 

 to the diatretynes, discussed below. 



Biformyne 1 is a polyacetylene which on catalytic reduction yields 

 a 9-carbon diol. 20 The positions of the ultraviolet absorption maxima 

 of the compound suggest a diendiyne system of unsaturation. The 

 low extinction coefficients of the maxima, however, would speak against 

 such a system, but, as was kindly pointed out to us by F. Bohlmann, 

 they are in better agreement with those of symmetrical triyne diols. 35 

 Oxidation of the reduction product with chromium trioxide in acetic 

 acid yields octanoic acid,* suggesting adjacent hydroxyl groups, one 

 of which is terminal, as in formula XII for the reduction product. 



H 3 C(CH 2 ) 6 CHOHCH 2 OH " 



XII 



The presence of a 1,2-diol grouping is supported by the results of 

 periodic acid oxidation of the reduction product, which yields formalde- 

 hyde. Formula XIII is suggested for biformyne 1 by formula XII, its 

 reduction product; by its absorption spectrum; and by the yield of an 

 immediate precipitate with silver nitrate. 



HC^C— C^C— C^C— CH 2 CHOHCH 2 OH 



XIII 



Biformyne 2, like agrocybin, apparently occurs in a bound form in 

 the culture liquid and is freed on boiling. The nature of the complex 

 is unknown in both cases. The fact that both agrocybin and biformyne 

 2 possess hydroxyl groups suggests that this group may be involved 

 in the attachment. 



The two polyacetylenes, diatretyne amide (XIV) and diatretyne 

 nitrile (XV) , along with agrocybin (XI) form a rather interesting 

 series. 



HOOC— C=C— C^C— feC— CONH 2 xiv 



HOOC— C=C— C=C— C=C— C=N xv 



* Unpublished work. 



