Isolation of labradorins 1 and 2 from Pseudomonas syringae pv. coronafaciens.
Pettit GR, Knight JC, Herald DL, Davenport R, Pettit RK, Tucker BE, Schmidt JM.
Investigation of Pseudomonas syringae pv. coronafaciens cancer cell growth inhibitory constituents led to the isolation of 2-isobutyl-5-(3-indolyl)oxazole (1) and 2-n-pentyl-5-(3-indolyl)oxazole (2f), designated labradorins 1 (1) and 2 (2f), related to pimprinine (2a). The structures were deduced by spectroscopic techniques and X-ray crystal structure determinations. Labradorin 1 (1) afforded GI(50) microg/mL values of 9.8 and 6.2 against the human cancer cell lines NCI-H 460 (lung-NSC) and BXPC-3 (pancreas-a).