Arch Pharm Res. 2007 Aug;30(8):919-23.
Isolation and structural elucidation of chemical constituents from the fruits of Morinda citrifolia Linn.
Siddiqui BS, Sattar FA, Ahmad F, Begum S.

Morinaphthalenone was identified in noni fruit.  (original abstract available at https://www.ncbi.nlm.nih.gov/pubmed/17879741).