Cyclohexene was oxidized to 2-cyclohexen-1-ol and 2-cyclohexen-1-one by atmospheric pressure of molecular oxygen in the presence of linear polystyrene-bound-2,29-bipyridine-ruthenium complexes in the absence of solvent at 70658C selectively. The alcohol / ketone molar ratio of the products can be ad
Selective oxidation of Zn2+—insulin catalyzed by Cu2+
✍ Scribed by Vikram Sadineni; Christian Schöneich
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 98 KB
- Volume
- 96
- Category
- Article
- ISSN
- 0022-3549
No coin nor oath required. For personal study only.
✦ Synopsis
The purpose of this study is to quantitate the sensitivity of Zn2+ -insulin to oxidation catalyzed by various redox active transition metals, Cu2+, Fe2+, Mn2+, Ni2+, Co2+, Cr3+. Human recombinant insulin (INS) was subjected to oxidation under various conditions in the presence and absence of Zn2+ and ascorbate. The extent of oxidation was monitored by RP-HPLC. Only Cu2+, but none of the other metals or combination thereof, for example, Ni2+/Co2+, Co2+/Cr3+, and Ni2+/Cr3+, catalyzed INS oxidation, for example, to an extent of 45% when 20 microM INS/8.8 microM Zn2+ were exposed to 8 microM Cu2+ and 50 microM ascorbate for 90 min. The Cu2+ -catalyzed oxidation mainly targeted the B chain of INS, where the two histidine residues are located.
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