Total Synthesis of the Illicium-Derived Sesquineolignan Simonsol C

Total synthesis of (±)-simonsol C using dearomatization as key reaction under acidic conditions

The total synthesis of (±)-simonsol C was accomplished using a dearomatization under acidic conditions as key step to construct an aryl-containing quaternary center. The 6/5/6 benzofuran unit was formed through reductive elimination with Zn/AcOH and a spontaneous oxy-Michael addition. This synthesis consists of 8 steps and achieves an overall yield of 13%, making it the shortest known route.

Total synthesis, biological evaluation and biosynthetic re-evaluation of Illicium-derived neolignans

We report the first total syntheses of simonsol F (3), simonsinol (5), fargenin (4), and macranthol (6) in addition to syntheses of simonsol C (2), simonsol G (1), and honokiol (14). The syntheses are based upon a phosphonium ylide-mediated cascade reaction and upon natural product isomerization reactions which proceed through Cope rearrangements of putative biosynthetic dienone intermediates. As a corollary of the natural product isomerization reactions, we propose an alternative biosynthesis of honokiol (14), simonsinol (5), and macranthol (6) which unites the natural products in this family under a single common precursor, chavicol (7). Finally, we demonstrate that simonsol C (2) and simonsol F (3) promote axonal growth in primary mouse cortical neurons.

Total Synthesis of (±)-Simonsol C

Total synthesis of simonsol C has been achieved, focusing on the postdearomatization transformations. Our methodology integrates an efficient combination of dearomatization and Zn/AcOH reduction to introduce an allyl group, followed by oxo-Michael addition, to construct the 6/5/6 benzofuran skeleton. It offers a novel method for synthesizing allyl-containing quaternary carbon atoms in a straightforward manner.

Asymmetric Syntheses of (+)- and (-)-Collybolide Enable Reevaluation of kappa-Opioid Receptor Agonism

The fungal metabolite collybolide has attracted attention as a non-nitrogenous, potent, and biased agonist of the kappa-opioid receptor (KOR). Here, we report a 10-step asymmetric synthesis of this complex sesquiterpene that enables facile access to either enantiomer. The synthesis relies on a diastereoselective α-benzoyloxylation to install the buried C6 benzoate and avoid irreversible translactonization of the congested, functionally dense core. Neither enantiomer, however, exhibited KOR agonism, indicating that collybolide has been mischaracterized as a KOR agonist. Given the pharmaceutical, medical, and societal interest in collybolide as a next-generation antipruritic and analgesic, this refutation of KOR activity has important ramifications for ongoing studies. Classification of collybolide as a new non-nitrogenous, KOR-selective, potent agonist with the same clinical potential as salvinorin A seems to have been premature.

Total Synthesis of Huperserratines A and B

Huperserratines A (1) and B (2), two novel macrocyclic Lycopodium alkaloids, possess an aza-12-membered ring. Here, we describe the first total synthesis of these two natural products in 12 steps....

CT2-3, a novel magnolol analogue suppresses NSCLC cells through triggering cell cycle arrest and apoptosis

Magnolol, a major bioactive component found in Magnolia officinalis with anti-inflammation and anti-oxidation activities as well as minimized cytotoxic effects. Although magnolol has a wide range of clinical applications, the anti-tumor activity of magnolol is not efficient. Herein, we reported the synthesis and anti-cancer activities of three novel magnolol analogues CT2-1, CT2-2, CT2-3, among which CT2-3 revealed more efficient anti-non-small cell lung cancer (NSCLC) activity than magnolol. Our data showed that CT2-3 could significantly inhibit the proliferation of human NSCLC cells in a dose-dependent manner. In addition, we revealed CT2-3 could induce cell cycle arrest through down-regulating mRNA expression of CDK4, CDK6 and cyclin D1. Moreover, we verified that CT2-3 could cause ROS generation, leading to apoptosis of human NSCLC cells. Further more, we also provided strong evidences that CT2-3 down-regulates the expression of c-Myc and topoisomerases, and contributes to the apoptosis of human NSCLC cells. Taken together, the current study is the first to report a promising new chemotherapeutic drug candidate CT2-3 that can efficiently eliminate human NSCLC cells through triggering cell cycle arrest as well as ROS-mediated and c-Myc/topoisomerases-mediated apoptosis.