Constituent of several plants belonging to the family Mimosaceae. First obtained from the seeds of Albizzia julibrissin Durazz., Mimosaceae: Gmelin et al., Z. Naturforsch. 13b, 252 (1958); Z. Physiol. Chem. 314, 28 (1959). Structure: Kjaer et al., Experientia 15, 253 (1959). Synthesis: Kjaer, Larsen, Acta Chem. Scand. 13, 1565 (1959); Rudinger et al., Collect. Czech. Chem. Commun. 25, 2022 (1960).