Chlorophyll b

Chlorophyll b

Names
IUPAC name Chlorophyll b
Systematic IUPAC name Magnesium [methyl (3S,4S,21R)-14-ethyl-13-formyl-4,8,18-trimethyl-20-oxo-3-(3-oxo-3-{[(2E,7R,11R)-3,7,11,15-tetramethyl-2-hexadecen-1-yl]oxy}propyl)-9-vinyl-21-phorbinecarboxylatato(2-)-κ2N,N']
Other names β-Chlorophyll
Identifiers
CAS Number	519-62-0 N
3D model (Jmol)	Interactive image
ChemSpider	16739843 Y
ECHA InfoCard	100.007.522
EC Number	208-272-4
E number	E140 (colours)
PubChem	6450186 11593175 (from spinach)
UNII	5712ZB110R N
InChI InChI=1S/C55H71N4O6.Mg/c1-12-38-35(8)42-27-43-36(9)40(23-24-48(61)65-26-25-34(7)22-16-21-33(6)20-15-19-32(5)18-14-17-31(3)4)52(58-43)50-51(55(63)64-11)54(62)49-37(10)44(59-53(49)50)28-46-39(13-2)41(30-60)47(57-46)29-45(38)56-42;/h12,25,27-33,36,40,51H,1,13-24,26H2,2-11H3,(H-,56,57,58,59,60,62);/q-1;+2/p-1/b34-25+;/t32-,33-,36+,40+,51-;/m1./s1 Y Key: NSMUHPMZFPKNMZ-VBYMZDBQSA-M Y InChI=1S/C55H72N4O6.Mg/c1-12-38-35(8)42-27-43-36(9)40(23-24-48(61)65-26-25-34(7)22-16-21-33(6)20-15-19-32(5)18-14-17-31(3)4)52(58-43)50-51(55(63)64-11)54(62)49-37(10)44(59-53(49)50)28-46-39(13-2)41(30-60)47(57-46)29-45(38)56-42;/h12,25,27-33,36,40,51H,1,13-24,26H2,2-11H3,(H2,56,57,58,59,60,62);/q;+2/p-2/b34-25+;/t32-,33-,36+,40+,51-;/m1./s1 Key: MSLKMRUEVOYOOZ-VBYMZDBQSA-L
SMILES CCC\1=C(c2/cc\3/c(c(c4/n3[Mg]n5c(/cc1\n2)c(c6c5/c(c/7\nc(\c4)[C@H]([C@@H]7CCC(=O)OC/C=C(\C)/CCC[C@H](C)CCC[C@H](C)CCCC(C)C)C)/[C@H](C6=O)C(=O)OC)C)C)C=C)C=O
Properties
Chemical formula	C55H70MgN4O6
Molar mass	907.49 g·mol−1
Appearance	Green
Odor	Odorless
Melting point	~ 125 °C (257 °F; 398 K)
Solubility in water	Insoluble
Solubility	Very soluble in EtOH, ether, C5H5N Soluble in MeOH
Absorbance	See text
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)

Chlorophyll b is a form of chlorophyll. Chlorophyll b helps in photosynthesis by absorbing light energy. It is more soluble than chlorophyll a in polar solvents because of its carbonyl group. Its color is yellow, and it primarily absorbs blue light.

In land plants, the light-harvesting antennae around photosystem II contain the majority of chlorophyll b. Hence, in shade-adapted chloroplasts, which have an increased ratio of photosystem II to photosystem I, there is a higher ratio of chlorophyll b to chlorophyll a. This is adaptive, as increasing chlorophyll b increases the range of wavelengths absorbed by the shade chloroplasts.