Cylindrocyclophane Biosynthesis Involves Functionalization of an Unactivated Carbon Center

The cylindrocyclophanes are a family of natural products that share a remarkable paracyclophane carbon scaffold. Using genome sequencing and bioinformatic analyses, we have discovered a biosynthetic gene cluster involved in the assembly of cylindrocyclophane F. Through a combination of in vitro enzyme characterization and feeding studies, we have confirmed the connection between this gene cluster and cylindrocyclophane production, elucidated the chemical events involved in initiating and terminating an unusual type I polyketide synthase (PKS) assembly line, and discovered that macrocycle assembly involves functionalization of an unactivated carbon center.Chemistry and Chemical Biolog

A Biocompatible Alkene Hydrogenation Merges Organic Synthesis with Microbial Metabolism

Organic chemists and metabolic engineers use largely orthogonal technologies to construct essential small molecules like pharmaceuticals and commodity chemicals. While chemists have leveraged the unique capabilities of biological catalysts for small molecule production, metabolic engineers have not likewise integrated reactions from organic synthesis with the metabolism of living organisms. Here we report a method for alkene hydrogenation that utilizes a palladium catalyst and hydrogen gas generated directly by a living microorganism. This biocompatible transformation, which requires both catalyst and microbe and can be used on a preparative scale, represents a new strategy for chemical synthesis that combines organic chemistry and metabolic engineering.Chemistry and Chemical Biolog

Predicting and Manipulating Cardiac Drug Inactivation by the Human Gut Bacterium Eggerthella lenta

Despite numerous examples of the effects of the human gastrointestinal microbiome on drug efficacy and toxicity, there is often an incomplete understanding of the underlying mechanisms. Here, we dissect the inactivation of the cardiac drug digoxin by the gut Actinobacterium Eggerthella lenta. Transcriptional profiling, comparative genomics, and culture-based assays revealed a cytochrome-encoding operon up-regulated by digoxin, inhibited by arginine, absent in nonmetabolizing E. lenta strains, and predictive of digoxin inactivation by the human gut microbiome. Pharmacokinetic studies using gnotobiotic mice revealed that dietary protein reduces the in vivo microbial metabolism of digoxin, with significant changes to drug concentration in the serum and urine. These results emphasize the importance of viewing pharmacology from the perspective of both our human and microbial genomes.Chemistry and Chemical Biolog

Cylindrocyclophane Biosynthesis Involves Functionalization of an Unactivated Carbon Center

The cylindrocyclophanes are a family of natural products that share a remarkable paracyclophane carbon scaffold. Using genome sequencing and bioinformatic analyses, we have discovered a biosynthetic gene cluster involved in the assembly of cylindrocyclophane F. Through a combination of <i>in vitro</i> enzyme characterization and feeding studies, we confirm the connection between this gene cluster and cylindrocyclophane production, elucidate the chemical events involved in initiating and terminating an unusual type I polyketide synthase assembly line, and discover that macrocycle assembly involves functionalization of an unactivated carbon center

Facile and Scalable Methodology for the Pyrrolo[2,1-f][1,2,4]triazine of Remdesivir

Pyrrolo[2,1-f][1,2,4]triazine (1) is an important regulatory starting material in the production of Remdesivir (Veklury®). Compound 1 was produced through a newly developed synthetic methodology utilizing the simple building blocks pyrrole, chloramine and formamidine acetate by examining the mechanistic pathway for the process optimization exercise. Triazine 1 was obtained in 55% overall yield in a two-reactor operated process. This work describes the safety of the process, impurity profiles and control, and efforts towards the scale-up of triazine for the preparation of kilogram quantity. <br /

Application of Chiral Transfer Reagents to Improve Stereoselectivity and Yields in the Synthesis of the Anti-Tuberculosis Drug Bedaquiline

Bedaquiline (BDQ) is an important drug for treating multidrug-resistant tuberculosis (MDR-TB), a worldwide disease that causes more than 1.6 million deaths yearly. The current synthetic strategy adopted by the manufacturers to assemble this molecule relies on a nucleophilic addition reaction of two complex starting materials, but suffers from low conversion and no stereoselectivity, which subsequently increases the cost of manufacturing BDQ. M4ALL has developed a new approach to this process that not only allows high conversion of starting materials, but also results in good diastereo- and enantioselectivity towards the desired BDQ stereoisomer. A variety of chiral lithium amides derived from amino acids were studied, and it was found that lithium (R)-2-(methoxymethyl)pyrrolidide, obtained from D-proline, results in high assay yield of the syn-diastereomer pair (82 %) and with considerable stereocontrol (d.r. = 13.6:1, e.r. = 3.6:1, 56 % ee) providing bedaquiline in up to 64 % assay yield before purification steps towards the final API. This represents a considerable improvement in the BDQ yield compared to previously reported conditions and could be critical to further lowering the cost of this life-saving drug

Synthesis and Biological Evaluation of Pentacyclic Strychnos Alkaloids as Selective Modulators of the ABCC10 (MRP7) Efflux Pump

The selective modulation of ATP-binding cassette (ABC) efflux pumps overexpressed in multidrug resistant cancers (MDR) and attendant resensitization to chemotherapeutic agents represent a promising strategy for treating cancer. We have synthesized four novel pentacyclic Strychnos alkaloids alstolucines B (<b>2</b>), F (<b>3</b>), and A (<b>5</b>) and <i>N</i>-demethylalstogucine (<b>4</b>), in addition to known Strychnos alkaloid echitamidine (<b>16</b>), and we evaluated compounds <b>1</b>–<b>5</b> in biochemical assays with ABCC10 and P-glycoprotein (P-gp). Alstolucines B (<b>2</b>) and F (<b>3</b>) inhibited ABCC10 ATPase activity at 12.5 μM without affecting P-gp function; moreover, they resensitized ABCC10-transfected cell lines to paclitaxel at 10 μM. Altogether, the alstolucines represent promising lead candidates in the development of modulators of ABCC10 for MDR cancers overexpressing this pump

Towards a Practical, Non-enzymatic Process for Molnupiravir from Cytidine

A scalable four step synthesis of molnupiravir from cytidine is described herein. The attractiveness of this approach is its fully chemical nature involving inexpensive reagents and more environmentally friendly solvents such as water, isopropanol, acetonitrile and acetone. Isolation and purification procedures are improved in comparison to our earlier report, as all intermediates can be isolated via aqueous acid treatment and recrystallization. The key steps in the synthesis, namely ester formation, hydroxamination and deprotection were done on multigram scale to afford molnupiravir in 36-41% yield with average purity of 98 wt% by q-NMR and 99 area % by HPL

Toward a Practical, Nonenzymatic Process for Investigational COVID-19 Antiviral Molnupiravir from Cytidine: Supply-Centered Synthesis

A scalable four-step synthesis of molnupiravir from cytidine is described herein. The attractiveness of this approach is its fully chemical nature involving inexpensive reagents and more environmentally friendly solvents such as water, isopropanol, acetonitrile, and acetone. Isolation and purification procedures are improved in comparison to our earlier study as all intermediates can be isolated via recrystallization. The key steps in the synthesis, namely, ester formation, hydroxyamination, and deprotection were carried out on a multigram scale to afford molnupiravir in 36-41% yield with an average purity of 98 wt % by qNMR and 99 area% by HPLC