Arutlesins

Arutlesins are a hypothetical class of natural products used in chemical education and model studies of polycyclic alkaloids. They are described as alkaloids with a fused indole-derived core, bearing multiple stereocenters and variable side chains. In this article, arutlesins are treated as a fictional concept to illustrate structure–activity relationships in natural products.

The core of arutlesins is envisioned as a tetracyclic framework comprising a bicyclic indole unit fused to an additional ring, with substituents at N-1 and C-3. Known members are arutlesin A, arutlesin B, and arutlesin C, differing primarily in side-chain composition and oxidation state. They are typically discussed as free bases or salts.

In the fictional scenario, arutlesins are reported from plant species in the genus Arutlea, particularly Arutlea silvatica, which are described as growing in temperate forests. Biosynthesis is proposed to proceed from tryptophan-derived precursors and polyketide units, via a series of cyclizations and oxidative steps, potentially encoded by a gene cluster named arutlesin-synthase.

In vitro assays have suggested anti-inflammatory, antimicrobial, and modest cytotoxic activities, with selectivity depending on the side chains. There is no clinical evidence, and no arutlesin-based therapies are approved.

Chemically, arutlesins are described as moderately lipophilic and possessing characteristic resonances for an indole core in NMR spectra. They are said to be accessible by synthetic routes that couple a tryptamine-derived unit with a polyketide surrogate, followed by ring closure and oxidation. Analytical identification relies on NMR, high-performance liquid chromatography–mass spectrometry, and comparison with reference standards.