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	Examples
A	Anodyne	No flags of any kind set	pattern_origin_fk is null	example
B	Reserved1	Future Use	no matches	example
C	PAINS sans mechanism	Worst problem is, PAINS without a clear mechanism matches	pattern_origin_fk =2	example
D	Reserved2	Future Use	no matches	example
E	mildly reactive	mildly electrophilic or nucleophilic group, including PAINS where these mechanisms have been assigned.	pattern_type_fk in (1,2)	aldhydes, thiols, michael acceptors, epoxides
F	Reserved3	Future Use	no matches	example
G	reactive	electrophile or nucleophile, including PAINS where these mechanisms have been assigned	pattern_type in (3,4)	alpha halo ketones, alkyl halides. Note includes cancer drugs.
H	Reserved4	Future use	no matches	example
I	Unstable	Highly reactive	pattern_origin=7	typically reagents, but could be used for covalent binding. e.g. boronic acids

other concepts mentioned, must be fit in: chelation, redox, covalent, amphiphilicity

poor derivatizability, optimizability

we never build protomers of H, G, F.

we need to classify pains by assumed mechanism

397 pains never hit any compound in zinc