New Constituents from Noni (Morinda citrifolia) Fruit Juice

Morinda citrifolia L. (Rubiaceae), known as noni, has a long history of traditional use in the Hawaiian and Tahitian islands. More recently, an array of commercial noni fruit juice products are gaining popularity as dietary supplements, with claims of anticancer and immunostimulant activities. The biologically active principles of noni are not fully known. In continuation of work on the isolation of markers from dietary supplements, this paper reports the isolation of three new markers, namely, 1-O-(3‘-methylbut-3‘-enyl)-β-d-glucopyranose (1), 1-n-butyl-4-(5‘-formyl-2‘-furanyl)methyl succinate (2), and 4-epi-borreriagenin (3), together with the known iridoid glycosides asperulosidic acid (4) and deacetylasperulosidic acid (5) and a mixture of 1-n-butyl-4-methyl-2-hydroxysuccinate (6a) and 1-n-butyl-4-methyl-3-hydroxysuccinate (6b), as well as a mixture of α- and β-glucopyranose from noni fruit juice obtained from Puerto Rico. The structures of compounds were based on 1H and 13C NMR, mainly 2D NMR COSY, HMQC, HMBC, and NOESY experiments, and HRMS. Furthermore, samples from fresh-squeezed noni fruit juice from Japan revealed the presence of scopoletin (7), in addition to compounds 1−6, indicating no significant differences in the marker constituents of noni collected from Atlantic and Pacific regions. Keywords: Noni; Morinda citrifolia; Rubiaceae; fruit juice; glycoside; iridoid; succinyl esters