What are Rotaxanes and Catenanes?

[n]Rotaxanes (Figure1A) are composed of a central dumbbell-shaped component encircled by nÀ1 trapped rings, while [n]catenanes (Figure 1B) contain n interlocked macrocycles. The prefix [n] indicates the number of me- chanically interlocked components, regardless of their identities.

Which is the main application of rotaxane?

The most frequently studied application of rotaxanes has been in the area of molecular switches. 6 The ring of a rotaxane is free to move along the rod component, but when functionality with an affinity for the ring component was installed on the rod, the ring’s position could be controlled.

What do catenanes do?

A catenane is a mechanically-interlocked molecular architecture consisting of two or more interlocked macrocycles, i.e. a molecule containing two or more intertwined rings. Catenanes have been synthesised in two different ways: statistical synthesis and template-directed synthesis.

How are Rotaxanes made?

(a) A rotaxane is formed from an open ring (R1) with a flexible hinge and a dumbbell-shaped DNA origami structure (D1). The ring is then closed around the dumbbell axis using closing strands (red), followed by the addition of release strands that separate dumbbell from ring via toehold-mediated strand displacement.

What is switch in chemistry?

A molecular switch is a molecule that can be reversibly shifted between two or more stable states. The molecules may be shifted between the states in response to environmental stimuli, such as changes in pH, light, temperature, an electric current, microenvironment, or in the presence of ions and other ligands.

What is Catenanes in biology?

Catenanes are species in which two ring molecules are interlocked with each other, i.e., each ring passes through the center of the other ring.

What is catenanes in biology?

What do you mean by catenanes?

A catenane is a mechanically-interlocked molecular architecture consisting of two or more interlocked macrocycles, i.e. a molecule containing two or more intertwined rings. The interlocked rings cannot be separated without breaking the covalent bonds of the macrocycles.

What is a biological switch?

Biological systems are adapted to respond quickly to changes in their environment. Signal processing often leads to all-or-none switch-like activation of downstream pathways. Such biological switches are based on molecular interactions that form positive feedback loops.

What is Rotaxanes chemistry?

Rotaxanes are unique supramolecular structures in which a cyclic molecule is threaded onto an “axle” molecule and end-capped by bulky groups at the terminal of the “axle” molecule.

What are catenanes in DNA replication?

Catenanes, or topologically linked circular molecules, were first extracted from living cells by Vinograd and co-workers (1,2). It was proven later that catenanes appear at the end of replication of circular DNA (3). Among those mechanisms an important role belongs to DNA supercoiling.