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Aporphine alkaloids have diverse pharmacological activities; however, our understanding of their biosynthesis is relatively limited. Previous studies have classified aporphine alkaloids into two categories based on the configuration and number of substituents of the D‐ring and have proposed preliminary biosynthetic pathways for each category. In this study, we identified two specific cytochrome P450 enzymes (CYP80G6 and CYP80Q5) with distinct activities toward (S)‐configured and (R)‐configured substrates from the herbaceous perennial vine Stephania tetrandra, shedding light on the biosynthetic mechanisms and stereochemical features of these two aporphine alkaloid categories. Additionally, we characterized two CYP719C enzymes (CYP719C3 and CYP719C4) that catalyzed the formation of the methylenedioxy bridge, an essential pharmacophoric group, on the A‐ and D‐rings, respectively, of aporphine alkaloids. Leveraging the functional characterization of these crucial cytochrome P450 enzymes, we reconstructed the biosynthetic pathways for the two types of aporphine alkaloids in budding yeast (Saccharomyces cerevisiae) for the de novo production of compounds such as (R)‐glaziovine, (S)‐glaziovine, and magnoflorine. This study provides key insight into the biosynthesis of aporphine alkaloids and lays a foundation for producing these valuable compounds through synthetic biology. [ABSTRACT FROM AUTHOR]

Swainsonine (SW, 1), a unique indolizine with poly‐hydroxyl groups, was re‐isolated from the plant endophytic fungus Alternaria oxytropis. The structure (including planar structure and relative configuration) was systematically elucidated by NMR spectra (including 1H, 13C, 1H‐1H COSY, HMQC, HMBC, and NOESY spectra in DMSO‐d6 and in CD3OD); 1H NMR spectra of the modified Mosher's products were first used to determine the absolute configuration of SW. More importantly, the complex coupled features of H‐7α, H‐7β, and H‐6α in the 1H NMR spectrum of (1) were analyzed in details, which will provide aids for the planar and relative configuration determination of analogs. [ABSTRACT FROM AUTHOR]