The answer to this comes in realizing that uracil is also structurally similar to the other DNA pyridine, cytosine, having an exocyclic
oxygen where cytosine has an amine (-NH2).
3]-12 placed exocyclic
H-6 away from the ring allowed the geometry of the C-6 double bond to be assigned as E.
The synthesis of compounds 5a-c was performed by the reduction of only the exocyclic
azomethine bond of the Schiff bases 4.
The Diels-Alder addition of PTAD to the exocyclic
diene in 25OHD produced a pair of diastereoisomers (Fig.
For instance, malondialdehyde (MDA) can react with deoxyguanosine in DNA to form an exocyclic
adduct, pyrimido[1,2-alpha]purin-10(3H)-one (M1G), which is mutagenic by resulting in frameshift mutations and base pair substitutions .
1] to exocyclic
methylene groups of labdanoids, and have drawn conclusions on the maturity of the amber by observing these bands, especially the one at 887 [cm.
The basic structure of geoporphyrins, especially those with an exocyclic
ring in the southern part of the molecule, is strongly suggestive of origin from chlorophylls and bacteriochlorophylls, which are major photosynthetic pigments of photoautotrophs.
An alpha methylene group exocyclic
to gamma lactone is considered to be essential for the induction of allergy.
MBT was found to be chemically adsorbed on the iron via the exocyclic
S and N atoms in acidic and neutral solutions, but was observed to be bound electrostatically in basic media.