In addition, TPP acts as a chain extender of PET, allowing the average chain length to be increased.
Uniquely, the tri-functional crosslinker, HBHBA, can act as a chain extender due to the presence of a low reactivity secondary hydroxyl, reducing the crosslink density of the HBHBA foam vs. that of DEOA foam.
As expected from the literature, the molecular weight of the copolymers decreased with increasing ITA concentration in the feed, which may be a consequence of the allylic hydrogen in ITA that can act as a chain transfer agent in radical polymerization [43, 44].
These euchromatic modifications may act as a chain terminator for the propagation process that generates methylated pericentromeric heterochromatin [12], [37].
Vitamin E is known to act as a chain breaking antioxidant that prevents the propagation of free radical reactions.
Contrarily, SUMO1 is attached as a monomer, or acts as a chain terminator on SUMO2/3 polymers (Matic et al., 2008; Okura et al., 1996; Tatham et al., 2001).
Chromosome 1D encodes a D-type LMW-GS containing a single cysteine residue and therefore may act as a chain terminator [ 53, 54].
The triphosphate analogue of gemcitabine can also be incorporated into DNA (in substitution for cytidine) where it acts as a chain terminator thereby inhibiting further DNA synthesis.
Therefore, a plausible mode for the antioxidant activity of MitoTEMPOL in mitochondria and cells is that it is rapidly converted to MitoTEMPOL-H within mitochondria and acts as a chain breaking antioxidant against free radicals by donating a hydrogen atom.
