What is the difference between isosteres and bioisosteres?
Classical Isosteres are molecules or ions with similar shape and often electronic properties. Many definitions are available. but the term is usually employed in the context of bioactivity and drug development. Such biologically-active compounds containing an isostere is called a bioisostere.
What do isostere & Bioisostere mean with brief discussion?
Friedman (1951): Bioisosteres are atoms or molecules that fit the broadest definition for isosteres and have the same type of biological activity. Thornber (1979): Groups or molecules which have chemical and physical similarities producing broadly similar biological effects.
What is meant by isostere?
: one of two or more substances (as carbon monoxide and molecular nitrogen) that exhibit similarity of some properties as a result of having the same number of total or valence electrons in the same arrangement and that consist of different atoms and not necessarily the same number of atoms.
What does Bioisostere mean in chemistry?
Bioisosteres – A bioisostere is a molecule resulting from the exchange of an atom or of a group of atoms with an alternative, broadly similar, atom or group of atoms. The objective of a bioisosteric replacement is to create a new molecule with similar biological properties to the parent compound.
What is Bioisostere importance in drug design?
Abstract. Introduction: A bioisostere is a powerful concept for medicinal chemistry. It allows the improvement of the stability; oral absorption; membrane permeability; and absorption, distribution, metabolism and excretion (ADME) of drug candidate, while retaining their biological properties.
What is the difference between Isoelectronic and isosteres?
The key difference between isoelectronic and isosteres is that isoelectronic chemical species have similar electronic configurations whereas isosteres are chemical species having similar size, the same number of atoms and valence electrons.
Which of the following is type of Bioisostere?
Bioisosteres are classiﬁed into the following two types: Classical bioisosteres. Nonclassical bioisosteres.
What are the types of bioisostere?
Is Alpha a type of bioisostere?
Bioisosterism of α-amino acids is often accomplished by replacing the α-carboxylate with one of the many known carboxylic acid bioisosteres. However, bioisosterism of the whole α-amino acid moiety is accomplished with heterocyclic bioisosteres that often display an acidic function.
Which of the following is a type of Bioisostere?
What is Isotone and isoelectronic?
ISOTONES: Are those elements which have same number of neutrons. Example:- C6N7O8 ( all have 8 electrons) ISOELECTRONIC: the species containing same number of electrons.
What is the difference between isotopes and isoelectronic?
So same number of protons, different number of neutrons. Or same atom with different masses. That’s an Isotope. When something is Isoelectronic, same but different, they have the same number of electrons.
Is Alpha a type of Bioisostere?
What are the types of Bioisostere?
Are CO and n2o isosteres?
ISOSTERES are atoms or molecules of similar size containing the same number of atoms and valence electrons. Thus the best example of isosteres are CO and N. Thus the answer is (2). the isostere concept was formulated bu Irvin Langmuir in 1917.
Are co2 and CO isosters?
Answer: All the given pairs are isosteres because all the pairs have the same number of atoms and the same number of electrons.
What are isotones and isobars?
The nuclei which have an identical number of nucleons, but different numbers of protons and different numbers of neutrons are called isobars. The nuclei having identical numbers of neutrons are called isotones. Their atomic number (Z) is the same but a mass number (A) is the same.
What is a bioisostere?
1951: H. L. Friedman coins “Bioisostere” – Molecules or groups “which fit the broadest definition of isosteres and have the same type of biological activity.” 1932: Erlenmeyer Demonstrates Bioisosterism of some of Langmuir’s Isosteres –
Where can I find information about potential bioisosteres?
There is also SwissBioisostere a web service designed to give ideas about potential bioisosteres, this is derived from a matched molecular pair (MMP) analysis of ChEMBL 17.
What are non-classical bioisosteres?
Non-classical bioisosteres may differ in a multitude of ways from classical bioisosteres, but retain the focus on providing similar sterics and electronic profile to the original functional group.
What is the objective of bioisosteric replacement?
The objective of a bioisosteric replacement is to create a new molecule with similar biological properties to the parent compound. The bioisosteric replacement may be physicochemically or topologically based.