Method for late introduction of the (
The presently disclosed subject matter demonstrates that ThnG and ThnQ enzymes encoded by the thienamycin gene cluster in Streptomyces cattleya oxidize the C-2 and C-6 moieties of carbapenems, respectively. ThnQ stereospecifically hydroxylates PS-5 giving N-acetyl thienamycin. ThnG catalyzes sequential desaturation and sulfoxidation of PS-5, giving PS-7 and its sulfoxide. The ThnG and ThnQ enzymes are relatively substrate selective, but give rise to the oxidative diversity of carbapenems produced by S. cattleya , and orthologues likely function similarly in allied streptomyces.
1. A process for preparing a carbapenem of Formula (I):
the process comprising contacting or incubating a carbapenem substrate of Formula (Ia):
with a purified ThnQ enzyme that stereospecifically hydroxylates the C8 carbon atom of the carbapenem substrate of Formula (Ia) under reaction conditions to produce an optically-pure carbapenem of Formula (I);
wherein:
R 1 is H;
R 2 is selected from the group consisting of —SCH 2 CH 2 NH 2 , —SCH═CHNHC(═O)CH 3 , —S-pantethienyl, —SCH 2 CH 2 NHC(═O)R′, wherein R′ is C 1 -C 10 substituted or unsubstituted linear or branched alkyl, which can be further substituted with one or more 3-6 member cycloalkyl rings, or aminoalkyl; and
R 3 is H.
2. The process of claim 1 , wherein R 2 is —SCH 2 CH 2 NHC(═O)R′, and wherein the —C(═O)R′ moiety is selected from the group consisting of glycyl, β-alanyl, 2-hydroxyacetyl, 2-methoxyacetyl, 3-hydroxypropionyl, 4-hydroxybutanoyl, and 3,4-dihydroxybutanoyl.
3. The process of claim 1 , wherein the compound of Formula (I) is selected from the group consisting of: