“…It should be pointed out that 9,lO-dihydrophenantrene-type structures of the molecule ions a of 1-16 shown in Schemes 1-3 are conjectural, but consistent with previously published literature data.l6sI7 The principal mass fragmentation pathways of N-substituted amino acids (3,6,9,12,15,17,19) are similar to those of their metameric methyl esters (1, 4, 7, 10, 13, 16, 18) and hydrazides (2, 5, 8,11,14) but show differences in the abundances of the important ions.…”