31. Porphyrins are doughnut-shaped molecules that have a metal atom where the hole would be.32. A later paper investigated using non-covalent bonding to attach the iron-containing porphyrin . 33. In porphyrin systems, the zinc ion appears to hinder the photodynamic activity of the compound. 34. Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. 35. Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins . 36. Compounds with interesting TPA properties also include various porphyrin derivatives, conjugated polymers and even dendrimers. 37. Porphyrins are synthesized from glycine and succinyl CoA, which condense to give ?-aminolevulinate.38. In plants, porphyrin and carotenoids constitute accessory pigments that help capture light in the photosystems. 39. Control of monomer assembly through covalent assembly has also been demonstrated using covalent interactions with porphyrins . 40. Chlorophyll has a porphyrin chlorin ring surrounding a magnesium ion and attached to a phytol tail.
