Bioassay-guided fractionation of the extract of the endophytic fungus KLAR 5 belonging to order Hypocreales, which was isolated from the twig of Knema laurina (Blume) Warb., resulted in the isolation of brefeldin A (1), 8-deoxy-trichothecin (2), trichothecolone (3), $7{alpha}$-hydroxytrichodermol (4), and $7{alpha}$-hydroxyscirpene (5). Compound 5 was isolated from natural source for the first time. Compound 1 was very highly active against human epidermoid carcinoma of the mouth, human breast cancer (BC-1), and human small cell lung cancer (NCI-H187) cells whereas compounds 2 and 4 were selectively active against BC-1 and NCI-H187 cells. Compounds 3 and 5 were moderately active against these three cancer cell lines.