A widely distributed metalloenzyme class enables gut microbial metabolism of host- and diet-derived catechols.

Catechol dehydroxylation is a central chemical transformation in the gut microbial metabolism of plant- and host-derived small molecules. However, the molecular basis for this transformation and its distribution among gut microorganisms are poorly understood. Here, we characterize a molybdenum-dependent enzyme from the human gut bacterium Eggerthella lenta that dehydroxylates catecholamine neurotransmitters. Our findings suggest that this activity enables E. lenta to use dopamine as an electron acceptor. We also identify candidate dehydroxylases that metabolize additional host- and plant-derived catechols. These dehydroxylases belong to a distinct group of largely uncharacterized molybdenum-dependent enzymes that likely mediate primary and secondary metabolism in multiple environments. Finally, we observe catechol dehydroxylation in the gut microbiotas of diverse mammals, confirming the presence of this chemistry in habitats beyond the human gut. These results suggest that the chemical strategies that mediate metabolism and interactions in the human gut are relevant to a broad range of species and habitats

Catalytic Synthesis of N-Unprotected Piperazines, Morpholines, and Thiomorpholines from Aldehydes and SnAP Reagents

ISSN:1433-7851ISSN:1521-3773ISSN:0570-083

Evidence for a Radical Mechanism in Cu(II)-Promoted SnAP Reactions

Saturated nitrogen heterocycles can be found with increasing abundance in bioactive molecules despite a limited number of methods to access these scaffolds. However, the coupling of recently introduced SnAP [tin (Sn) amine protocol] reagents with a wide range of aldehydes and ketones has proven to be a reliable, practical, and versatile one-step approach to saturated N-heterocycles. While effective, the lack of mechanistic understanding limits efforts to develop new catalytic and enantioselective variants. To distinguish between a polar or radical mechanism, we assessed Lewis and Brønsted acids, radical trapping experiments, and radical clock SnAP reagents reinforcing the current understanding of the SnAP protocol as a radical cyclization.ISSN:1437-2096ISSN:0936-521

SnAP-eX Reagents for the Synthesis of Exocyclic 3‑Amino- and 3‑Alkoxypyrrolidines and Piperidines from Aldehydes

SnAP-eX (tin amine protocol, exocyclic heteroatoms) reagents allow the single-step transformation of aldehydes and ketones into 2,3-disubstituted pyrrolidines and piperidines containing exocyclic amine or alkoxy groups. These saturated N-heterocycles are of importance in modern drug discovery approaches and are prepared in moderate yields using an operationally simple protocol that is compatible with a range of functional groups and heterocyclic aldehydes

Synthesis of maculalactone A and derivatives for environmental fate tracking studies

Maculalactone A () constitutes a promising antifouling agent, inhibiting the formation of biofilms in marine and freshwater systems. In this study, we developed a new route, based on a late-stage formation of the butenolide core, leading to the total synthesis of maculalactone A (three steps, overall yield of 45%) and delivering material on a gram scale. In addition, analogues of the title compound were assayed concerning their biological activity, utilizing Artemia franciscana and Thamnocephalus platyurus. The most active analogue was functionalized with a rhodamine B fluorophore and was utilized in an in vivo staining experiment in Artemia salina. Two different tissues were found to accumulate this maculalactone A derivative

SnAP reagents for the synthesis of piperazines and morpholines

ISSN:1523-7060ISSN:1523-705

SnAP reagents for the one-step synthesis of medium-ring saturated N-heterocycles from aldehydes

ISSN:1755-4349ISSN:1755-433

ChemInform Abstract: SnAP Reagents for the One-Step Synthesis of Medium-Ring Saturated N-Heterocycles from Aldehydes.

ISSN:1755-4349ISSN:1755-433

Copper Promoted Oxidative Coupling of SnAP Hydrazines and Aldehydes to Form Chiral 1,4,5-Oxadiazepanes and 1,2,5-Triazepanes

ISSN:0018-019XISSN:1522-267

SnAP Reagents for a Cross-Coupling Approach to the One-Step Synthesis of Saturated N-Heterocycles

ISSN:0002-510