TERPENOIDS 



243 



/8-D-glucoside, darutoside, and certain cardiac glycosides. Surprisingly, 

 in one species, Acanthosicyos horrida, cucurbitacins occur as glycosides 

 in the roots and as aglycones in the fruit. According to Meeuse (1954) 

 most, if not all, genera producing the cucurbitacins are in the sub- 

 family Cucurbitaceae (for example, Momordica, Bryonia, Ecballium, 

 Citrullus, Cucumis, Lagenaria, Cucurbita, and Sphaerosicyos). 



Two cucurbitacins, designated B and E, are thought to be the 

 primary cucurbitacins, since other than cucurbitacin C these two are 

 the only ones which sometimes occur alone in mature plants, and 

 seedlings of all twenty-one species studied contained mainly B and/or 

 E, even in species containing up to eight different cucurbitacins. The 

 empirical formulas of B and E are given below: 



Cucurbitacin B C32H48O8 

 Cucurbitacin E C32H44O8 



Apparently the cucurbitacin content within a species may 

 vary greatly since several genera {Citrullus, Cucumis, and Lagenaria) 

 occur in bitter and non-bitter forms. In the case of Cucurbita pepo 

 var. ovifera from one to eight different cucurbitacins may occur, 

 though certain combinations are favored. Enslin and Rehm found 

 that genetic, environmental, and developmental factors influence the 

 cucurbitacin content. 



The value of the cucurbitacin studies is further enhanced by 



Table 13-1. Relative amounts of constituents in peppermint type oils" (Reitsema 

 in Jour. Amer. Pharm. Assoc, Sci. Ed. 47: 268. 1958— by permission). 



" Absence of quantitative data indicates lack of data rather than an implied absence of the compound in the oil. 

 ' Identified by chromatography and ultraviolet absorption. 

 ' Indicates presence without quantitative data. 



