Chemistry Reference
In-Depth Information
CCO enzymes is frequently a regulated process with additional biochemical steps that create the
biologically active apocarotenoid (Iuchi et al. 2000, Simkin et al. 2004a,b, Rodrigo et al. 2006).
In the following section we will discuss the different types of CCOs that have been isolated and
characterized over the last decade.
NCEDs
O
OH
OH
Arabidopsis (NCED)
Bean
Maize
Citrus
11,12
HO
O
O
OH
O
O
HO
O
9-
cis
-Violaxanthin
Xanthoxin (C
15
)
Absisic acid
Arabidopsis (CCD
1
)
Pea
Maize
Tomato
CCDs
9,10 (9',10')
β-Ionone
O
O
O
β,β-Carotene
C
14
Dialdehyde
Arabidopsis (CCD
7
)
Pea
Maize
13,14
β-lonone
9',10'
Mouse (BCOII)
O
O
β-Apo-10'-carotenal
β,β-Carotene
Arabidopsis (CCD
8
)
Pea
Maize
O
O
O
C
9
Dialdehyde
β-Apo-13-carotenone
7,8 (7',8')
ZCDs
Crocus sativus (ZCD)
OH
O
O
O
HO
HO
Zeaxanthin
OR
O
O
O
R
1
OR
Safranal (R = H)
Crocetin (R = H)
LCDs
Picrocrocin (R = glucose)
Crocin (R = gentobiose)
5,6 (5',6')
Bixa orellana (BoLCD)
O
O
O
OH
Bixin
Lycopene
Human (BCOI)
Mouse
Rat
Drosophila
Zebra ish
BCO
15,15'
O
Retinal
β,β-Carotene
Synechocystis sp. PCC
6803
(AcoSYN)
Synechococcus sp. PCC
7942
Nostoc sp. PCC
7120
ACOs
15,15'
O
O
β-Apo-8'-carotenal
Retinal
FIGURE 19.1
Representative cleavage patterns observed by assorted CCO enzymes. Carotenoid cleavage
enzymes can be designated into several classes based on substrate specii city and cleavage site regioselec-
tivity. NCEDs cleave the 11,12-double bond; CCDs cleave the 9,10-(9′,10′-) position excluding a few excep-
tions (LCD and ZCD); BCO1s are mammalian enzymes that cleave the 15,15′-position; ACOs are microbial
enzymes that cleave apocarotenoids at the 15,15′-double bond.
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