Reactivity axis

Here we describe the "clean" axis in the exported subsets of ZINC15.

Traditionally, ZINC standard subsets included: A, B, C, D, E.

ZINC "clean" subsets were just A, B, C, D.

The Clean Axis

Class	Nickname	Description / How computed
A	Anodyne	No flags of any kind set
B	Unnecessarily complex	The worst feature is the molecules are over decorated e.g. too many chlorides
C	Chromophore	Worst problem is a chromophore that could interfere with some asays
D	Any PAINS	Any pains pattern not covered in E,F,G,H
E	mildly electrophilic or nucleophilic	aldhydes, thiols, michael acceptors, epoxides
F	strongly electrophilic or nucleophilic	alpha halo ketones, alkyl halides
G	unstable in buffer	typically, reagents used in synthesis, but could be used for covalent binding. e.g. boronic acids
H	nonsensical	idea from the PAINS papers