Sideroxylonal C (3), (2RS,3RS,4RS)-2-(3,5-diformyl-2,4,6-trihydroxyphenyl)-
5,7-dihydroxy-3-(1-methylethyl)-4-(2-methylpropyl)chroman-6,8-dicarbaldehyd
e, was isolated from Eucalyptus melliodora leaf, and its structure determin
ed by spectroscopic methods.