Merck + Co., Inc.

Gist-brocades B.v.

Christopher D Reeves

John A Rambosek

Michael J Conder

Phyllis C McAda

Victor A Vinci

Charles Ray Davis

Lee E Hendrickson

Robert W Stieber

Rebecca L Dabora

William H Cover

Anderson Hong

DNA encoding triol polyketide synthase (TPKS) has been isolated, purified and sequenced. Expression vectors comprising TPKS, cells transformed with the expression vectors, and processes employing the transformed cells are provided.

DNA encoding triol polyketide synthase

A bioprocess for preparing adipoyl-7-ACA comprising the steps: (a) transforming cells of a strain of Penicillium chrysogenum which produces isopenicillin N with an expression vector containing DNA encoding an enzyme, having expandase activity capable of accepting adipoyl 6-APA as a substrate, an enzyme having hydroxylase activity capable of accepting adipoyl-7-ADCA as a substrate and an enzyme having acetyl transferase activity capable of accepting adipoyl 7-ADAC as a substrate; (b) culturing the transformed cells from step a) in a suitable culture medium containing an adipate feedstock, wherein said cells produce adipoyl 6-APA; and (c) culturing the transformed cells producing adipoyl 6-APA of step b) under conditions suitable for expression of said DNA encoding enzyme, thereby producing the end product adipoyl-7-ACA.

Bioprocesses for preparing 7-ACA and 7-ADAC

A process for making 7-aminodeacetyl-cephalosporanic acid (7-ADAC).

Important intermediates for preparing cephalosporin antibiotics, 7-amino-cephalosporanic acid (7-ACA) and 7-aminodeacetylcephalosporanic acid (7-ADAC), are prepared by a novel bioprocess in which a transformed Penicillium chrysogenum strain is cultured in the presence of an adipate feedstock to produce adipoyl-6-APA (6-amino penicillanic acid); followed by the in situ expression of the following genes with which the P. chrysogenum has been transformed: 1) an expandase gene, whose expression product converts the adipoyl-6-APA by ring expansion to adipoyl-7-ADCA; 2) an hydroxylase gene whose expression product converts the 3-methyl side chain of adipoyl-7-ADCA to 3-hydroxymethyl, to give the first product, 7-aminodeacetylcephalosporanic acid (7-ADAC); and 3) an acetyltransferase gene whose expression product converts the 3-hydroxymethyl side chain to the 3-acetyloxymethyl side chain of 7-ACA. The final product, 7-ACA, is then prepared by cleavage of the adipoyl side chain using an adipoyl acylase. The entire synthesis, accordingly, is carried out using bioprocesses, and is efficient and economical.

Recombinant bioprocess for the preparation of 7-amino cephalosporanic

Important intermediates for preparing cephalosporin antibiotics, 7-amino-cephalosporanic acid (7-ACA) and 7-aminodeacetylcephalosporanic acid (7-ADAC), are prepared by a novel bioprocess in which a transformed Penicillium chrysogenum strain is cultured in the presence of an adipate feedstock to produce adipoyl-6-APA (6-amino penicillanic acid); followed by the in situ expression of the following genes with which the P. chrysogenum has been transformed:

Bioprocess for preparing 7-ACA and 7-ADAC

Novel strains of Aspergillus terreus have been discovered which provide fermentation production of at least 5.2 g/L of 7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-hydroxy-1(S)-naphthyl ]-3(R),5(R)-dihydroxyheptanoic acid (triol acid, I), but with production of not more than 0.85 g/L of (triol acid)-related side products and specifically less than 0.10 mg/liter of lovastatin. The predominant fermentation product triol acid, may be converted in a straightforward manner to its lactone form, in which it is an inhibitor of HMG-CoA reductase and thus useful as an antihypercholesterolemic agent, and in which it may also serve as an intermediate for preparation of other HMG-CoA reductase inhibitors.

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Woodinville, WA, United States of America

Christopher D Reeves