4 -Integerrine-type cyclopeptide alkaloids

It has already been mentioned that in 4(14)-frangulanine-type cyclopeptide alkaloids R is the P-OH-Leucine side chain, while in 4(14)-integerrine-type cyclopeptide alkaloids R is the P-OH-Phenyla-lanine side chain. This leads to the generalization shown in Table 5. 

Fig. 2. Main fragments of 4(14)-frangulanine- and -integerrine-type cyclopeptide alkaloids...

Table 5. m/z Values of Fragments of 4(14)-Frangulanine- or -Integerrine-Type Cyclopeptide Alkaloids... 

The main fragmentation pattern of this category follows that of the 4(14)-frangulanine-, -integerrine- and -pandamine-type cyclopeptide alkaloids and exhibits the same a-m and q-v fragments. 

Lotusanine-B displays the following 5(14)-scutianine-A-type fragments e, f, i, m, q, q". In addition, fragments x, x-CO, y, y-CO of 4(14)-frangulanine-, -integerrine- and -pandamine-type cyclopeptide alkaloids appear. Finally fragments n and o, analogues of n and o of 5(14)-amphibine-B-type cyclopeptide alkaloids occur (Fig. 22). 

The cyclopeptide alkaloids of the integerrine type differ from those discussed in the previous section in that the /3-hydroxyleucine in the ring... 

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