Xviii CONTENTS 



VI. Carotenoids and Related Compounds (continued) 



a. Structure 533 



b. Occurrence 534 



c. Related Compounds 536 



(a) a-Carotene Mono-epoxide , 536 



(b) Flavochrome 537 



(c) Oxy-a-carotene 537 



(d) Semi-a-carotenone 538 



(e) a-Apo-2-carotenal 538 



(f ) a-Apo-2-carotenol 538 



(g) 5,6-Dihydro-a-carotene 539 



(3) 7-Carotene 539 



a. Pro-7-Carotene and Stereoisomeric Forms 541 



(4) Other Carotenes 542 



(5) Lycopene 542 



a. Structure 543 



b. Occurrence 544 



c. Related Compounds 546 



(a) Prolycopene 546 



(b) Perhydrolycopene 546 



(c) Dehydrolycopene 546 



(d) Apo-2-lycopenal 546 



(e) Apo-3-lycopenal 547 



(f) Apo-2,12-lycopendial 547 



(g) Apo-3,12-lycopendial 547 



(h) Lycopersene 548 



2. Structure and Occurrence of Carotenols and Oxycarotenols of the C40 



Series 548 



(1) Lycoxanthin and Lycophyll 548 



(2) Cryptoxanthiu 549 



a. Structure 549 



b. Occurrence 550 



c. Related Compounds 551 



(a) Cryptoxanthin Mono-epoxide 551 



(b) Cryptoflavin 551 



(c) Cryptoxanthin Di-epoxide 552 



(d) Cryptochrome 552 



(e) czs-/rans-Isomers 552 



(3) Rubixanthin 552 



(4) Lutein (Xanthophyll) 553 



a. Structure 554 



b. Occurrence 555 



c. Related Compounds 559 



(a) Helenien 559 



(b) Lutein Epoxide 559 



(c) a-Citraurin 561 



(d) Perhydrolutein 561 



(5) Zeaxanthin 561 



a. Occurrence 562 



b. Related Compounds 663 



(a) Physalien 563 



