| The porphyrins and metalloporphyrins are a class of naturally occurring aromatic tetrapyrrole macrocyclic compounds, which play a very important role in living organisms. For examples, chlorophylls act as the primary light receptors and energy conversion in photosynthesis; haem is involved in electron transfer processes and acts as the molecular oxygen-carrier in biological systems. Owing to the biological importance of porphyrins, many synthesized porphyrins have also been used for clinic application or as models for biomimic studies.From a structural standpoint, the porphyrin nucleus is a tetradentate ligand, which can coordinate with almost all metals. With the extensive application of rare earths in agriculture and biomedicine, as well as the increasing severity of heavy metals pollution in environment, rare earths and other heavy metals can be taken in by living organism directly or indirectly, which thus results in the formation of porphyrin complexes with these metals in vivo. To explore the bioactivities of this kind of bioorganic compounds, it is necessary to study the preparation and isolation of porphyrin complexes with rare earths and other metals, and to investigate the properties of them. In this paper, a study on the porphyrin complexes with rare earths, lead and cadmium is taken, summarized as the following:(1) The rare earth porphyrin in vivo is likely to be a mixture of complexes of different porphyrin with different central ions, so it is essential to investigate the separation of multiple compositions of rare earth porphyrins. In view of separation, the separation of porphyrin complexes with different central metal ions is more difficult. Because of little differene of ion radius among rare earths, the separation of porphyrin complexes with heavy rare earth ions is further more difficult.We firstly succeeded in the separation of the new cationic complexes of tetrakis (4-methoxyphenyl) porphyrin with yttrium, erbium, thulium and ytterbium (RE-TMOPP-C1) by reserved-phase high performance liquid chromatography. It was found that this kind of porphyrin complexes could be effectively separated only with the mobile phase containing amine together with organic acid. In the same conditions,IVthe elution strength of acids or amines decreased in the following order: acetic acid > propionic acid > formic acid or triethylamine > triethanolamine > dibutylamine > dihexylamine >diethylamine ~ diethanolamine > ethanolamine > ethylamine. Among amines, triethanolamine (TEOLA) was the best additives for the separation of RE-TMOPP-C1 complexes. No matter what type of organic acids or amines, RE-TMOPP-C1 complexes was eluted in the order of the decrease of ionic radius of rare earths; good linear relationship between log k of RE-TMOPP-C1 and EN / rf of RE was obtain in different content of TEOLA. Successful separation of the RE-TMOPP-C1 complexes in 10 min was achieved at a flow rate of 0.5ml /min, with the mobile phase of methanol-water (85:15,v:v) containing 100 mmol/L TEOLA and 200 mmol/L HAc.(2) Chromatographic behaviors of six cationic thulium porphyrin complexes have been firstly investigated in different mobile phase. Thulium porphyrins (Tm-TMOPP, Tm-TPP, Tm-TMPP, Tm-p-ClTPP and Tm-p-iPrTPP) could not be eluted with the mobile phase not containing amine other than Tm-THPP, but the six thulium porphyrins could be effectively eluted with the mobile phase containing HAc together with TEOLA. Their retention factors increased just in the order of the hydrophobic capacity of the substituted group in aromatic cycle. The whole analysis was completed on a Qg column in 18min at a flow rate of 0.5 ml/min, with the mobile phase of methanol-water (93:7,v:v) containing 75 mmol/L TEOLA and 200 mmol/L HAc, or with the mobile phase of ethanol-water (90:10,v:v) containing 25 mmol/L TEOLA and 200 mmol/L HAc pumped at 0.25 ml/ min. Compared with the methanol system, the ethanol system was a better candidate for the separation of thulium porphyrin complexes in view of selectivity.(3) Preparation of pure chlor...
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