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Characterization of HETEs and related conjugated dienes by UV spectroscopy
Author(s) -
Ingram Christiana D.,
Brash Alan R.
Publication year - 1988
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02537345
Subject(s) - chromophore , double bond , conjugated system , chemistry , photochemistry , spectroscopy , diene , stereochemistry , organic chemistry , polymer , physics , natural rubber , quantum mechanics
Three distinct pairs of HETEs can be distinguished on the basis of their UV spectra. We used hydroxy‐linoleates (hydroxy‐octadeca‐ cis‐trans ‐dienoates) as a base for comparisons; both the 9‐ and 13‐hydroxy isomers have identical chromophores with λ max near 234 nm. The presence of a double bond three carbons removed from the conjugated diene (the chromophore of 9‐ and 11‐HETE) causes a shift in the observed λ max to near 235 nm. A double bond β to the chromophore (5‐ and 15‐HETE) gives a further shift of 1.5 nm, giving a λ max between 236–236.5 nm. With double bonds in both these positions (8‐ and 12‐HETE), the λ max is observed near 237 nm. It is apparent that the exact λ max of the cis‐trans diene chromophore is influenced in a consistent way by the adjacent methylene interrupted cis double bonds.