studies designed to test these hypotheses are planned. Also pres- 

 ent, albeit in very small amounts, was an alkaloid of a new 

 structural type which we had named ''funebrine" (V) and which 

 represents the first alkaloid to be recorded in the Bombacaceae. It 

 was accompanied by at least two other polar alkaloidal com- 

 pounds in quantities too small to permit characterization at the 

 present time. 



Finally, the isolation of a novel amino acid, 2S,3S,4R-4- 

 hydroxyisoleucine (I) in substantial amounts allowed us to pro- 

 pose a biogenetic scheme for the synthesis by the plant of the 

 above compounds as shown in the accompanying figure. The 

 novelty of this amino acid lies in the fact that it appears to be a 

 diasteriomer new in nature; its epimer, 2S,3R,4R-4-hydroxyi- 

 soleucine, had been isolated from fenugreek seed (Fowden, 1973) 

 and was found to be a component of a-amanitin (Wieland, 1968). 

 The fact that I could be converted readily to 11 was of obvious 

 help in defining the geometry of the other compounds in the 

 series. 



Among the non-nitrogenous constituents of the remaining 

 aqueous fractions of the ethanolic extract were rather large quan- 

 tities of glucose, fructose and sucrose. This leads to the suggestion 

 that the flowers served the additional purpose of sweenening the 

 Zapotec chocolate drinks, inasmuch as sugar cane was not known 

 in the New World until after the Conquest. A small amount of a 

 complex mixture of flavonoids was also present, but no individ- 

 ual compounds were identified. 



During the course of the study, a small sample of Quararihea 

 turhinata leaves became available to us. The chemical profile of 

 these was very similar to that of the Q. funebris flowers; com- 

 pounds I, II and 111 were identified, the presence of alkaloids was 

 established and compound IV, though not yet isolated and identi- 

 fied, is suspected to be present by reason of the familiar odor of 

 the extracts. We have recently acquired several other species of 

 the Quararihea I Matisia complex and will be interested to learn 

 whether any one or all of these compounds will serve to distin- 

 guish the genera in this portion of the Bombacaceae of whether, 

 indeed, they are characteristic of the family. 



154 



