Alkaloid Structures

Structures of alkaloid biosynthetic glucosidases decode substrate specificity.

Two similar enzymes with different biosynthetic function in one species have evolved to catalyze two distinct reactions. X-ray structures of both enzymes help reveal their most important differences. The Rauvolfia alkaloid biosynthetic network harbors two O-glucosidases: raucaffricine glucosidase (RG), which hydrolyses raucaffricine to an intermediate downstream in the ajmaline pathway, and str...

Cinchona Alkaloid

Catalytic Asymmetric Reactions of 4‐Substituted Indoles with Nitroethene: A Direct Entry to Ergot Alkaloid Structures

A domino Friedel-Crafts/nitro-Michael reaction between 4-substituted indoles and nitroethene is presented. The reaction is catalyzed by BINOL-derived phosphoric acid catalysts, and delivers the corresponding 3,4-ring-fused indoles with very good results in terms of yields and diastereo- and enantioselectivities. The tricyclic benzo[cd]indole products bear a nitro group at the right position to ...

Design, Synthesis and Evaluation of New Marine Alkaloid-Derived Pentacyclic Structures with Anti-Tumoral Potency

This work describes the synthesis and biological evaluation of a new heterocyclic hybrid derived from the ellipticine and the marine alkaloid makaluvamine A. Pyridoquinoxalinedione 12 was obtained in seven steps with 6.5% overall yield. 12 and its intermediates 1-11 were evaluated for their in vitro cytotoxic activity against different cancer cell lines and tested for their inhibitory activity ...

Transcription factors in alkaloid biosynthesis.

Higher plants produce a large variety of low-molecular weight secondary compounds. Among them, nitrogen-containing alkaloids are the most biologically active and are often used pharmaceutically. Whereas alkaloid chemistry has been intensively investigated, alkaloid biosynthesis, including the relevant biosynthetic enzymes, genes and their regulation, and especially transcription factors, is lar...