In organic chemistry, atoms other than carbon and hydrogen are generally referred to as heteroatoms. The most common heteroatoms are nitrogen, oxygen and sulfur. Now I present to you an article called Influence of pH on radical reactions between kynurenic acid and amino acids tryptophan and tyrosine. Part II. Amino acids within the protein globule of lysozyme, published in 2021-10-31, which mentions a compound: 492-27-3, mainly applied to Back electron transfer; Cross-linking; Kynurenic acid; Lysozyme; Oxygenation; Protonation; Radicals; UV-A light, Computed Properties of C10H7NO3.
An acidosis, a decrease of pH within a living tissue, may alter yields of radical reactions if participating radicals undergo partial or complete protonation. One of photosensitizers found in the human eye lens, kynurenic acid (KNA-), possesses pKa 5.5 for its radical form that is close to physiol. pH 6.89 for a healthy lens. In this work we studied the influence of pH on mechanisms and products of photoinduced radical reactions between KNA- and amino acids tryptophan (Trp) and tyrosine (Tyr) within a globule of model protein, Hen White Egg Lysozyme (HEWL). Our results show that the rate constant of back electron transfer from kynurenyl to HEWL• radicals with the restoration of initial reagents – the major decay pathway for these radicals – does not change in the pH 3-7. The quantum yield of HEWL degradation is also pH independent, however a shift of pH from 7 to 5 completely changes the outcome of photoinduced damage to HEWL from intermol. crosslinking to oxygenation. HPLC-MS anal. has shown that four of six Trp and all Tyr residues of HEWL are modified in different extents at all pH, but the lowering of pH from 7 to 5 significantly changes the direction of main photodamage from Trp62 to Trp108 located at the entrance and bottom of enzymic center, resp. A decrease of intermol. cross-links via Trp62 is followed by an increase in quantities of intramol. cross-links Tyr20-Tyr23 and Tyr23-Tyr53. The obtained results point out the competence of crosslinking and oxygenation reactions for Trp and Tyr radicals within a protein globule and significant increase of oxygenation to the total damage of protein in the case of crosslinking deceleration by coulombic repulsion of pos. charged protein globules.
There is still a lot of research devoted to this compound(SMILES：O=C(C1=NC2=CC=CC=C2C(O)=C1)O)Computed Properties of C10H7NO3, and with the development of science, more effects of this compound(492-27-3) can be discovered.
Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”