Investigation of chemical constituents from the bark of Durio carinatus has led to the isolation of three lignans, boehmenan X (1), threo-carolignan X (2), and erythro-carolignan X (3), together with the three known lignans boehmenan, threo-carolignan E, and erythro-carolignan E. The bark of D. oxleyanus yielded two new lignan ethers, threo-carolignan Y (4) and erythro-carolignan Y (5), together with compounds 1, 3, and boehmenan. J-Based configurational analysis and NOE measurements were used to explore conformational issues for the lignan diastereomers, while CD measurements supported an 8'S configuration for the various lignans. The triterpenes 3β-O-cis-caffeoylbetulinic acid and 3β-O-trans-caffeoylbetulinic acid were also characterized from D. carinatus.