The first total synthesis of mycocyclosin, a diketopiperazine natural product isolated from M. tuberculosis, is described. While direct oxidative coupling of tyrosine phenolic groups was unsuccessful, construction of the highly strained bicyclic framework was successfully accomplished through an intramolecular Miyaura-Suzuki cross-coupling to generate the biaryl linkage.
Structure–Activity Relationships of cyclo(l-Tyrosyl-l-tyrosine) Derivatives Binding to Mycobacterium tuberculosis CYP121: Iodinated Analogues Promote Shift to High-Spin Adduct
摘要:
A series of analogues of cyclo(L-tyrosyl-L-tyrosine), the substrate of the Mycobacterium tuberculosis enzyme CYP121, have been synthesized and analyzed by UV-vis and electron paramagnetic resonance spectroscopy and by X-ray crystallography. The introduction of iodine substituents onto cyclo(L-tyrosyl-L-tyrosine) results in sub-mu M binding affinity for the CYP121 enzyme and a complete shift to the high-spin state of the heme Fe-III. The introduction of halogens that are able to interact with heme groups is thus a feasible approach to the development of next-generation, tight binding inhibitors of the CYP121 enzyme, in the search for novel antitubercular compounds.
作者:Xu Zhu、Christopher C. McAtee、Corinna S. Schindler
DOI:10.1021/acs.orglett.8b00894
日期:2018.5.18
We report herein the scalable total synthesis of the secondary metabolite, mycocyclosin, initially isolated from Mycobacterium tuberculosis. Mycocylosin bears a highly strained 3,3′-dityrosine biaryl system which arises biosynthetically from an intramolecular oxidative dehydrogenative cross-coupling of cyclo(l-Tyr-l-Tyr) (cYY) catalyzed by the P450 enzyme CYP121. CYP121 is found exclusively in M. tuberculosis