What does Isosteres mean?

What does Isosteres mean?

Classical isosteres are defined as being atoms, ions and molecules that had identical outer shells of electrons, This definition has now been broadened to include groups that produce compounds that can sometimes have similar biological activities.

What are examples of Isosteres?

Nitrogen, carbon monoxide and the cyanide ion are isosteric molecules; their electronic Lewis structures are identical: :N:::N: :C:::O: :C:::N: In general, isosteric molecules have the same shape. This is a consequence of their identical electron arrangements.

What is bioisosterism with example?

6.  APPLICATION OF CLASSICAL BIOISOSTERISM IN DRUG DESIGN. Replacement of monovalent atom.  Example  The substitution of hydrogen atom by fluorine is the one of the most commonly employed monovalent isosteric replacement. Steric parameter for hydrogen and fluorine are similar.

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.

What are classical isosteres?

Classical bioisosteres Classical bioisosterism was originally formulated by James Moir and refined by Irving Langmuir as a response to the observation that different atoms with the same valence electron structure had similar biological properties.

How many types of classical isosteres are there?

Classical bioisosteres can be further subdivided into five classes: 1) monovalent atoms or groups (D and H; F and H; C and Si; Cl, Br, SH, and OH; NH and OH; RSH and ROH, –Cl, –PH2, –SH), 2) divalent atoms or groups (–CH2, –NH, –O, –S, –Se–, -COCH2-), 3) trivalent atoms or groups (–CH=, –N=, -P=, -As=), 4) tetravalent …

What does bioisostere mean in chemistry?

Definition of Bioisosterism. 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 are bioisostere groups?

In medicinal chemistry, bioisosteres are chemical substituents or groups with similar physical or chemical properties which produce broadly similar biological properties to another chemical compound.

What are Isodiaphers and isosteres?

Mass number (A) = Number of protons (Z) + Number of neutrons. Isoelectronic: Species/ elements having same number of electron. Isodiaphers: Elements having same value of |(A−2Z)| Isotopes: Atoms having same number of proton.

What is isosteres 11?

We can define isostere as the molecules or ions that have a similar shape and often have similar electronic properties.