地质体中脱金属卟啉的研究——付克乙酰化反应的应用

Investigation of Demetallated Geoporphyrins: An Application of Friedel-Crafts Acetylation

本文用付克乙酰化反应;TLC、Probe—MS方法对地质卟啉进行了研究。结果表明本文所采用的方法可以粗略地分离卟啉的同分异构体;也可以比较清楚地研究β-(H)未取代卟啉的特征,如一海相样品(Lmk6)中的A—4类主要以β-(H)未取代形式存在;β-(H)未取代卟啉富含低碳数的化合物;A-8类卟啉主要为β-(H)全烷化卟啉等.这一研究还指出了不同类型铜卟啉的TLC行为.

It is well-known that β-(H) unsubstituted porphyrins present in sediments exclusively. Recently, several β-(H) unsubstituted porphyrins have been isolated by HPLC and identified by CI-MS and 'HNMR. However, many aspects of their characterisation remain unresolved. In the present papers, Friedel-Crafts acetylation, thin layer chromatography and Probe-MS are used for investigation of geoporphyrins in Lmk6. Ten red bands were obtained from TLC plate. The results show the methods could separated the porphyrin isomers roughly, and are able to reveal the characterisation of β-(H) unsubstituted porphyrins. For instance, A-4 series mainly occurs in β -(H) unsubstituted fraction and A-8 series only appears in fully alkylated fraction. Normally, β-(H) unsubstituted porphyrins are rich in the compounds of low carbon numbers. Results also show the TLC behaviour of Cu porphyrins. For fully alkylated porphyrins, Rf of A series > that of A-2 and A-4 > that of A-8. However, for β-(H) unsubstituted porphyrins. Rf ofAseries < that of A-2 series.