Set of Cytochrome P450s Cooperatively Catalyzes the Synthesis of a Highly Oxidized and Rearranged Diterpene-Class Sordarinane Architecture

Abstract

Cytochrome P450s are one of the most versatile oxidases that catalyze significant and unique chemical transformations for the construction of complex structural frameworks during natural product biosynthesis. Here, we discovered a set of P450s, including SdnB, SdnH, SdnF, and SdnE, that cooperatively catalyzes the reshaping of the inert cycloaraneosene framework to form a highly oxidized and rearranged sordarinane architecture. Among them, SdnB is confirmed to be the first P450 (or oxidase) that cleaves the C−C bond of the epoxy residue to yield formyl groups in pairs. SdnF selectively oxidizes one generated formyl group to a carboxyl group and accelerates the final Diels−Alder cyclization to furnish the sordarinane architecture. Our work greatly enriches the enzyme functions of the P450 superfamily, supplies the missing skills of the P450 synthetic toolbox, and supports them as biocatalysts in further applications toward the synthesis of new chemical entities.

Oxygen‐18 Labeling Reveals a Mixed Fe−O Mechanism in the Last Step of Cytochrome P450 51 Sterol 14α‐Demethylation

“…However, the authors indicate that a Baeyer–Villiger rearrangement could also explain their results. Another possibility of a P450 Baeyer–Villiger reaction is that of Sordaria araneosa SdnB [39] …”

“…Another possibility of a P450 Baeyer-Villiger reaction is that of Sordaria araneosa SdnB. [39] The best case for Baeyer-Villiger P450 chemistry may be the study of Fischer et al [12c] on lanosterol 14α-demethylation in rat liver microsomes. While it is generally accepted that the P450 51 reaction culminates in cleavage of the C14-C32 bond of 14α-CHO lanosterol, their group identified a competing reaction facilitated by Baeyer-Villiger type chemistry (Scheme 3B) that yielded a third oxidative intermediate in the reaction series.…”

Fungal P450 Deconstructs the 2,5-Diazabicyclo[2.2.2]octane Ring En Route to the Complete Biosynthesis of 21R-Citrinadin A

“…They usually mediate a typical monooxygenation reaction via the canonical “oxygen rebound” mechanism to insert a single oxygen atom into the C–H, CC, N–H, or S–H bonds . With an increasing number of characterized P450s, the substrate radical generated by the high active oxoiron­(IV) species can initiate more complex oxidation such as C–C bond formation and cleavage. , Notably, the nucleophilic attack of the heme-Fe III hydroperoxide complex contributes to the realization of some uncommon reactions, such as epoxidation catalyzed by Fma-P450 , and C–C bond cleavage mediated by Baeyer–Villiger rearrangement catalyzed by CYP 17, JCM 1, and SdnB . Accordingly, we propose that the CtdY catalysis may proceed through a mechanism in which the carbonyl of the amide bond in 20 might be attacked by heme-Fe III hydroperoxide species resulting in the cleavage of the C–N bond.…”

“…40,42 Notably, the nucleophilic attack of the heme-Fe III hydroperoxide complex contributes to the realization of some uncommon reactions, such as epoxidation catalyzed by Fma-P450 43,44 and C−C bond cleavage mediated by Baeyer− Villiger rearrangement catalyzed by CYP 17, 45 JCM 1, 46 and SdnB. 47 Accordingly, we propose that the CtdY catalysis may proceed through a mechanism in which the carbonyl of the amide bond in 20 might be attacked by heme-Fe III hydroperoxide species resulting in the cleavage of the C−N bond. The subsequent decarboxylation initiated by the attack of N-11 provided the iminium intermediate 21 (Figure 3F).…”

Hot off the Press

“…A series of four cytochrome P450 enzymes have been shown to catalyse the consecutive steps during the rearrangement of the cycloaraneosene skeleton to the fungal diterpene, sordaricin ( 23 , Scheme 1). 17 In vivo and in vitro studies have allowed characterisation of the enzymes, including SdnB, which is the first example of a P450 enzyme to cleave a C–C bond of an epoxide, generating two aldehyde functional groups. Both enantiomers of isotopically labelled hedycaryol 24 , an important sesquiterpene alcohol, have been prepared using a mutant plant and a bacterial enzyme.…”