“…Comparison of the 13 C-NMR data of essramycin with values of related synthetic compounds of type 1 delivered, however, a much better agreement with the experimental values than with compounds of type 2, confirming the skeleton of 1 [15,16]: A C-2 substituent affects the ipso C atom of 1,2,4-triazolo[1,5-a]pyrimidines, however, the influence on the 13 C shifts of the other ring atoms is negligible (Table 4). [1,2,4]Triazolo[1,5-a]pyrimidines have found a broad interest as fungicides [17], herbicide safener [18,19], kinase inhibitors [20,21], antiparasitic [22] and plant protecting agents [23]. Thousands of compounds of this type have been described, however, to the best of our knowledge, not a single natural product is amongst them [6,24,25].…”