Angustifonine A (1) had a molecular formula of C41H44N4O4,
as deduced from 13C NMR data and the HRESIMS ion at m/z
657.3433 ([M + H]+, calcd 657.3440), with 22 indices of
hydrogen deficiency. IR absorption bands at 3379 and 1678
cm−1 indicated the presence of amino or hydroxy groups and
ester carbonyl functionalities, respectively.