Carotenoids from guava (Psidium guajava']java L.):: Isolation and structure elucidation

Sixteen carotenoids were isolated from the flesh of Brazilian red guavas (Psidium guajava L.). Their structures were established by means of UV-visible, 400 and 500 MHz H-1 NMR, 120 and 125 MHz C-13 NMR, mass, and circular dichroism spectra. The carotenoids were identified as phytofluene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-beta-carotene, (all-E)-gamma-carotene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-lycopene, (all-E,3R)-beta-cryptoxanthin, (all-E,3R)-rubixanthin, (all-E,3S,5R,8S)-cryptoflavin, (all-E,3R,3'R,6'R)-lutein, (all-E,3S,5R,6R,3'S,5'R,8'R)-, and (all-E,3S,5R,6R,3'S,5'R,8'S)-neochrome. Thirteen of the carotenoids identified are reported as guava carotenoids for the first time.