HR-MAS NMR of fruits of plants belonging to the Rutaceae family

Citrus, as one of the worldwide favourite fruits, draws more attention recently due to its therapeutic potentials. In animal models, d-limonene and structural analogues have demonstrated strong chemopreventive effects in lymphomas, mammary, gastric, liver, and lung cancers. [P.L. Crowell, M.N. Gould, Crit. Rev. Oncog. 5, 1, 1994] Limonoids, citrus secondary metabolites, seem to have multiple bioactive functions, including anticancer, reducing cholesterol, anti-anxiety, antimicrobial, and antiviral activities. [G. D. Manners, J. Agric. Food Chem. 2007, 55, 8285.] This is a HR-MAS NMR study on samples from exocarp, mesocarp, endocarp and seeds of Citrus Medica and Citrus Limon fruits aimed at to the evaluation of the potentialities of the technique in the detection and identification of terpenes in different parts of the fruit.1D (water-presaturated, spin-echo and diffusion-filtered spectra) as well as 2D NMR experiments (COSY, TOCSY and HSQC) are carried out at 4 °C on different regions of the commercial fruit cut in pieces that can fit the HR-MAS 4 mm rotor and directly put into it. Attempts at gaining some insight into the dimensions of oil bodies in the flavedo through diffusion experiments will be also presented.