RESUMO
We report the discovery and biosynthesis of new piperazine alkaloids-arizonamides, and their derived compounds-arizolidines, featuring heterobicyclic and spirocyclic isoquinolone skeletons, respectively. Their biosynthetic pathway involves two crucial non-heme iron enzymes, ParF and ParG, for core skeleton construction. ParF has a dual function facilitating 2,3-alkene formation of helvamide, as a substrate for ParG, and oxidative cleavage of piperazine. Notably, ParG exhibits catalytic versatility in multiple oxidative reactions, including cyclization and ring reconstruction. A key amino acid residue Phe67 was characterized to control the formation of the constrained arizonamide B backbone by ParG.
Assuntos
Alcaloides , Alcaloides/química , Alcaloides/metabolismo , Alcaloides/biossíntese , Piperazinas/química , Piperazinas/metabolismo , Ferro/química , Ferro/metabolismo , Ciclização , Biocatálise , Estrutura Molecular , Compostos de Espiro/química , Compostos de Espiro/metabolismo , Oxirredução , Piperazina/química , Piperazina/metabolismoRESUMO
(-)-Antrocin (1), produced by the medicinal mushroom Antrodia cinnamomea, is a potent antiproliferative compound. The biosynthetic gene cluster of 1 was identified, and the pathway was characterized by heterologous expression. We characterized a haloacid dehalogenase-like terpene cyclase AncC that biosynthesizes the drimane-type sesquiterpene (+)-albicanol (2) from farnesyl pyrophosphate (FPP). Biochemical characterization of AncC, including kinetic studies and mutagenesis, demonstrated the functions of two domains: a terpene cyclase (TC) and a pyrophosphatase (PPase). The TC domain first cyclizes FPP to albicanyl pyrophosphate, and the PPase domain then removes the pyrophosphate to form 2. Intriguingly, AncA (94 % sequence identity to AncC), in the same gene cluster, converts FPP into (R)-trans-γ-monocyclofarnesol instead of 2. Notably, Y283/F375 in the TC domain of AncA serve as a gatekeeper in controlling the formation of a cyclofarnesoid rather than a drimane-type scaffold.
Assuntos
Agaricales , Sesquiterpenos , Terpenos/metabolismo , Difosfatos , Agaricales/metabolismo , Anticorpos Anticitoplasma de Neutrófilos , Cinética , Sesquiterpenos/química , Pirofosfatases/metabolismo , Família MultigênicaRESUMO
Piperazine-derived diazabicycles are privileged structures found in natural products and synthetic chemical entities, including therapeutic agents. Herein, we deciphered the biosynthesis of two unique classes of diazabicyclic alkaloids, fischerazines A-C. Notably, we characterized a multifunctional P450 monooxygenase NfiC that installs ortho-dihydroxyl groups on the dibenzyl-piperazines, in turn triggering a range of NfiC-catalyzed and spontaneous cyclization events.
Assuntos
Alcaloides , Peptídeo Sintases , Sistema Enzimático do Citocromo P-450/química , Peptídeo Sintases/química , PiperazinaRESUMO
(-)-Aurantioclavine (1), which contains a characteristic seven-membered ring fused to an indole ring, belongs to the azepinoindole class of fungal clavine alkaloids. Here we show that starting from a 4-dimethylallyl-l-tryptophan precursor, a flavin adenine dinucleotide (FAD)-binding oxidase and a catalase-like heme-containing protein are involved in the biosynthesis of 1. The function of these two enzymes was characterized by heterologous expression, in vitro characterization, and deuterium labeling experiments.