Nevertheless, more than half of the known circRNAs do not have complementary flanking in the intronic sequences, as it has been reported that 38% of all known Caenorhabditis elegans circRNAs and 9% of all known human circRNAs can be recognized using the base-pairing potential to cyclize
the exons .
Inorganic ferrous ion ([Fe.sup.2+]) or organic ferric ions such as in cytochrome c (Cy-[Fe.sup.3+]) may alternatively convert HPNE (17) to the corresponding alkoxyl radical (21), which can abstract or lose a hydrogen to form HNE (22) or ONE (23), respectively, or cyclize
to form epoxyalkyl radical (24), which rearranges to oxygen-stabilized vinyl ether radical (25) [113, 114].
Adding of compound 1 to ylidene malononitrile would yielded polyfunctionally intermediate compound 16, which is anticipated to cyclize
into 5-(2,2-dicyano-1-phenylvinyl)-2,5-dihydro-2-aminothiophene-3-carbonitrile derivatives 17a-c.
This interesting work shows that exactly the right purified solution of linear organic molecules can cyclize
under the right conditions to present activated nucleotides.
A diepoxide is also formed that will cyclize
and generate the THF-diol that we identified from corncob bedding (Mani et al.
To further enhance the antigenicity of these peptides, later work may include introducing several constraints to these peptides to increase structural rigidity, such as by adding linkers to cyclize
the linear peptides or disulfide bonds for peptide stabilization.
At 240|degrees~C the pendant vinyl groups will begin to cyclize
thermally with no peroxide, but for any temperature below, a high temperature peroxide is required.
Using amine 28 and 4-fluorobenzaldehyde shown in Scheme 10, Awuah and Capretta combined microwave conditions and acid-catalysis to condense and cyclize
the imine adduct at [C.sub.8f]-[C.sub.1] followed by dehydrogenation to produce the 2-(4-fluorophenyl) isoquinoline 29a in excellent overall yield.
[H.sub.2]S is oxidized to [H.sub.2][S.sub.n] species with a varying number of sulfur atoms until the number of sulfur atoms reaches eight, at which point the sulfur molecules cyclize
The intermediate free radicals formed after cyclization can cyclize
again to form bicycle endoperoxides, structurally related to prostaglandins, and undergo cleavage to produce MDA.
The P450-dependent hydroxylation of the methoxy group yields an intermediate corresponding to the hemiacetal of formaldehyde that can cyclize
to form a methylenedioxy bridge via an ionic mechanism involving the methylene oxonium ion intermediate.
Four molecules of this porphyrin precursor cyclize
and undergo several side-chain modifications to yield the tetrapyrrole protoporphyrin.