Production of Multiple Talaroenamines from Penicillium malacosphaerulum via One-Pot/Two-Stage Precursor-Directed Biosynthesis

Nineteen new talaroenamine derivatives, talaroenamines F1-F19 (1-19), were isolated from the Yellow River wetland derived Penicillium malacosphaerulum HPU-J01 by use of a one-pot/two-stage precursor-directed biosynthesis approach. During this approach, the initial precursor p-methylaniline was first used as a carrier to capture the biologically synthesized cyclohexanedione to produce talaroenamine F, and then the Other aniline derivatives were employed to replace the p-methylaniline fragment of talaroenamine F to generate the final products. LC-MS analysis showed that only four compounds (2, 8, 10, and 12) could be produced by the traditional precursor-directed biosynthesis in which the aniline precursors were added simultaneously. Compound 14 was cytotoxic against the K562 cell line with an IC₅₀ value of 2.2 μM. This work demonstrated the one-pot/two-stage precursor-directed biosynthesis could improve substrate acceptance leading to the production of diverse talaroenamines.