Video Experimental Relacionado

Updated: Oct 15, 2025

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Published on: February 7, 2019

Formación de nitrociclopropano estereodivergente durante la biosíntesis de las belactosinas y las hormaomicinas

Shotaro Shimo¹, Richiro Ushimaru^1,2,3, Alicia Engelbrecht⁴

¹Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.

Journal of the American Chemical Society

|October 28, 2021

Resumen

Este estudio revela cómo las enzimas BelK, HrmI, BelL y HrmJ sintetizan aminoácidos únicos que contienen ciclopropano que se encuentran en productos naturales. Estas enzimas controlan la estereoquímica durante la formación de 3- ((2-nitrociclopropil) alanina.

Área de la Ciencia:

La bioquímica
Síntesis de productos naturales
Enzimología

Sus antecedentes:

Las belactosinas y las hormaomicinas son péptidos naturales que contienen residuos de aminoácidos que contienen ciclopropano.
Estos residuos, 3- ((2-aminociclopropil) alanina y 3- ((2-nitrociclopropil) alanina, poseen configuraciones estereoscópicas de anillos de ciclopropano opuestas.

Objetivo del estudio:

Elucidar los mecanismos enzimáticos para sintetizar los anillos de ciclopropano en las belactosinas y las hormaomicinas.
Identificar las enzimas específicas y sus funciones en la formación estereocontrolada de estos aminoácidos inusuales.

Principales métodos:

Investigó la N-oxigenación de la l-lisina utilizando enzimas similares a la hemooxigenasa (BelK y HrmI).
Se analizó la ciclopropanación del intermedio nitroalcano resultante utilizando enzimas de hierro no hemo (BelL y HrmJ).
Determinación de los resultados estereoquímicos de las reacciones de ciclización.

Principales resultados:

Se demostró que BelK y HrmI catalizan la N-oxigenación de la l-lisina a la 6-nitronorleucina.
BelL y HrmJ fueron identificados como ciclopropanasas que forman el anillo de nitrociclopropano con una estereoquímica específica.
Las reacciones de ciclopropanación implican la eliminación del 4-proS-hidrógeno de la 6-nitronorleucina, lo que lleva a la inversión (BelL) o la retención (HrmJ) de la configuración en C4.

Conclusiones:

El estudio revela una nueva estrategia enzimática para la síntesis estereocontrolada de anillos de ciclopropano en la naturaleza.
Las enzimas y mecanismos identificados proporcionan información sobre la biosíntesis de productos naturales complejos de péptidos.

Más Videos Relacionados

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones

A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones

Published on: January 21, 2020

Videos de Conceptos Relacionados

Diels–Alder Reaction Forming Cyclic Products: Stereochemistry

Diels–Alder Reaction Forming Cyclic Products: Stereochemistry

The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.

Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry

Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry

Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.

Prochirality

Prochirality

The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...

Stereoisomerism of Cyclic Compounds

Stereoisomerism of Cyclic Compounds

In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...

Biosynthesis in Bacteria

Biosynthesis in Bacteria

Biosynthesis in bacteria is a fundamental anabolic process that generates essential macromolecules, including proteins, nucleic acids, lipids, and polysaccharides. These macromolecules are critical for cellular growth, replication, and function. The process is tightly regulated and energetically linked to catabolic pathways to ensure optimal resource utilization.Biosynthetic pathways begin with precursor metabolites such as pyruvate, acetyl-CoA, and glucose-6-phosphate derived from glycolysis,...

Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview

Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview

Cyanohydrins are compounds that contain –CN and –OH groups on the same carbon atom. They are formed by the nucleophilic addition of the cyanide ions to the carbonyl group. Cyanide ions are highly basic and nucleophilic and can be generated from HCN under aqueous conditions. However, since HCN is a weak acid, the number of cyanide ions generated is very small. Hence, a small amount of base or KCN/NaCN is added to HCN to increase the concentration of the cyanide ions in the reaction...