#
#              SMARTS Patterns for Functional Group Classification
#
#              written by Christian Laggner
#              Copyright 2005 Inte:Ligand Software-Entwicklungs und Consulting GmbH
#
#              Released under the Lesser General Public License (LGPL license)
#              see http://www.gnu.org/copyleft/lesser.html
#              Modified from Version 221105
#####################################################################################################

# General Stuff:
# These patters were written in an attempt to represent the classification of organic compounds
# from the viewpoint of an organic chemist.
# They are often very restrictive. This may be generally a good thing, but it also takes some time
# for filtering/indexing large compound sets.
# For filtering undesired groups (in druglike compounds) one will want to have more general patterns
# (e.g. you don't want *any* halide of *any* acid, *neither* aldehyde *nor* formyl esters and amides, ...).
#

# Part I: Carbon
# ==============


# I.1: Carbon-Carbon Bonds
# ------------------------

# I.1.1 Alkanes:

Primary_carbon: [CX4H3][#6]

Secondary_carbon: [CX4H2]([#6])[#6]

Tertiary_carbon: [CX4H1]([#6])([#6])[#6]

Quaternary_carbon: [CX4]([#6])([#6])([#6])[#6]


# I.1.2 C-C double and Triple Bonds

Alkene: [CX3;$([H2]),$([H1][#6]),$(C([#6])[#6])]=[CX3;$([H2]),$([H1][#6]),$(C([#6])[#6])]
# sp2 C may be substituted only by C or H -
# does not hit ketenes and allenes, nor enamines, enols and the like

Alkyne: [CX2]#[CX2]
# non-carbon substituents (e.g. alkynol ethers) are rather rare, thus no further discrimination

Allene: [CX3]=[CX2]=[CX3]


# I.2: One Carbon-Hetero Bond
# ---------------------------


# I.2.1 Alkyl Halogenides

Alkylchloride: [ClX1][CX4]
# will also hit chloromethylethers and the like, but no chloroalkenes, -alkynes or -aromats
# a more restrictive version can be obtained by modifying the Alcohol string.

Alkylfluoride: [FX1][CX4]

Alkylbromide: [BrX1][CX4]

Alkyliodide: [IX1][CX4]


# I.2.2 Alcohols and Ethers

Alcohol: [OX2H][CX4;!$(C([OX2H])[O,S,#7,#15])]
# nonspecific definition, no acetals, aminals, and the like

Primary_alcohol: [OX2H][CX4H2;!$(C([OX2H])[O,S,#7,#15])]

Secondary_alcohol: [OX2H][CX4H;!$(C([OX2H])[O,S,#7,#15])]

Tertiary_alcohol: [OX2H][CX4D4;!$(C([OX2H])[O,S,#7,#15])]

Dialkylether: [OX2]([CX4;!$(C([OX2])[O,S,#7,#15,F,Cl,Br,I])])[CX4;!$(C([OX2])[O,S,#7,#15])]
# no acetals and the like; no enolethers

Dialkylthioether: [SX2]([CX4;!$(C([OX2])[O,S,#7,#15,F,Cl,Br,I])])[CX4;!$(C([OX2])[O,S,#7,#15])]
# no acetals and the like; no enolethers

Alkylarylether: [OX2](c)[CX4;!$(C([OX2])[O,S,#7,#15,F,Cl,Br,I])]
# no acetals and the like; no enolethers

Diarylether: [c][OX2][c]

Alkylarylthioether: [SX2](c)[CX4;!$(C([OX2])[O,S,#7,#15,F,Cl,Br,I])]

Diarylthioether: [c][SX2][c]

Oxonium: [O+;!$([O]~[!#6]);!$([S]*~[#7,#8,#15,#16])]
# can't be aromatic, thus O and not #8

# I.2.3 Amines

Amine: [NX3+0,NX4+;!$([N]~[!#6]);!$([N]*~[#7,#8,#15,#16])]
# hits all amines (prim/sec/tert/quart), including ammonium salts, also enamines, but not amides, imides, aminals, ...

# the following amines include also the protonated forms

Primary_aliph_amine: [NX3H2+0,NX4H3+;!$([N][!C]);!$([N]*~[#7,#8,#15,#16])]

Secondary_aliph_amine: [NX3H1+0,NX4H2+;!$([N][!C]);!$([N]*~[#7,#8,#15,#16])]

Tertiary_aliph_amine: [NX3H0+0,NX4H1+;!$([N][!C]);!$([N]*~[#7,#8,#15,#16])]

Quaternary_aliph_ammonium: [NX4H0+;!$([N][!C]);!$([N]*~[#7,#8,#15,#16])]

Primary_arom_amine: [NX3H2+0,NX4H3+]c

Secondary_arom_amine: [NX3H1+0,NX4H2+;!$([N][!c]);!$([N]*~[#7,#8,#15,#16])]

Tertiary_arom_amine: [NX3H0+0,NX4H1+;!$([N][!c]);!$([N]*~[#7,#8,#15,#16])]

Quaternary_arom_ammonium: [NX4H0+;!$([N][!c]);!$([N]*~[#7,#8,#15,#16])]

Secondary_mixed_amine: [NX3H1+0,NX4H2+;$([N]([c])[C]);!$([N]*~[#7,#8,#15,#16])]

Tertiary_mixed_amine: [NX3H0+0,NX4H1+;$([N]([c])([C])[#6]);!$([N]*~[#7,#8,#15,#16])]

Quaternary_mixed_ammonium: [NX4H0+;$([N]([c])([C])[#6][#6]);!$([N]*~[#7,#8,#15,#16])]

Ammonium: [N+;!$([N]~[!#6]);!$(N=*);!$([N]*~[#7,#8,#15,#16])]
# only C and H substituents allowed. Quaternary or protonated amines
# NX4+ or Nv4+ is not recognized by Daylight's depictmatch if less than four C are present


# I.2.4 Others

Alkylthiol: [SX2H][CX4;!$(C([SX2H])~[O,S,#7,#15])]

Dialkylthioether: [SX2]([CX4;!$(C([SX2])[O,S,#7,#15,F,Cl,Br,I])])[CX4;!$(C([SX2])[O,S,#7,#15])]

Alkylarylthioether: [SX2](c)[CX4;!$(C([SX2])[O,S,#7,#15])]

Disulfide: [SX2D2][SX2D2]

1,2-Aminoalcohol: [OX2H][CX4;!$(C([OX2H])[O,S,#7,#15,F,Cl,Br,I])][CX4;!$(C([N])[O,S,#7,#15])][NX3;!$(NC=[O,S,N])]
# does not hit alpha-amino acids, enaminoalcohols, 1,2-aminoacetals, o-aminophenols, etc.

1,2-Diol: [OX2H][CX4;!$(C([OX2H])[O,S,#7,#15])][CX4;!$(C([OX2H])[O,S,#7,#15])][OX2H]
# does not hit alpha-hydroxy acids, enolalcohols, 1,2-hydroxyacetals, 1,2-diphenols, etc.

1,1-Diol: [OX2H][CX4;!$(C([OX2H])([OX2H])[O,S,#7,#15])][OX2H]

Hydroperoxide: [OX2H][OX2]
#does not neccessarily have to be connected to a carbon atom, includes also hydrotrioxides

Peroxo: [OX2D2][OX2D2]

Organolithium_compounds: [LiX1][#6,#14]

Organomagnesium_compounds: [MgX2][#6,#14]
# not restricted to Grignard compounds, also dialkyl Mg

Organometallic_compounds: [!#1;!#5;!#6;!#7;!#8;!#9;!#14;!#15;!#16;!#17;!#33;!#34;!#35;!#52;!#53;!#85]~[#6;!-]
# very general, includes all metals covalently bound to carbon


# I.3: Two Carbon-Hetero Bonds (Carbonyl and Derivatives)
# ----------------------------

# I.3.1 Double Bond to Hetero

Aldehyde: [$([CX3H][#6]),$([CX3H2])]=[OX1]
# hits aldehydes including formaldehyde

Ketone: [#6][CX3](=[OX1])[#6]
# does not include oxo-groups connected to a (hetero-) aromatic ring

Thioaldehyde: [$([CX3H][#6]),$([CX3H2])]=[SX1]

Thioketone: [#6][CX3](=[SX1])[#6]
# does not include thioxo-groups connected to a (hetero-) aromatic ring

Imine: [NX2;$([N][#6]),$([NH]);!$([N][CX3]=[#7,#8,#15,#16])]=[CX3;$([CH2]),$([CH][#6]),$([C]([#6])[#6])]
# nitrogen is not part of an amidelike strukture, nor of an aromatic ring, but can be part of an aminal or similar

Immonium: [NX3+;!$([N][!#6]);!$([N][CX3]=[#7,#8,#15,#16])]

Oxime: [NX2](=[CX3;$([CH2]),$([CH][#6]),$([C]([#6])[#6])])[OX2H]

Oximether: [NX2](=[CX3;$([CH2]),$([CH][#6]),$([C]([#6])[#6])])[OX2][#6;!$(C=[#7,#8])]
# ether, not ester or amide; does not hit isoxazole


# I.3.2. Two Single Bonds to Hetero

Acetal: [OX2]([#6;!$(C=[O,S,N])])[CX4;!$(C(O)(O)[!#6])][OX2][#6;!$(C=[O,S,N])]
# does not hit hydroxy-methylesters, ketenacetals, hemiacetals, orthoesters, etc.

Hemiacetal: [OX2H][CX4;!$(C(O)(O)[!#6])][OX2][#6;!$(C=[O,S,N])]

Aminal: [NX3v3;!$(NC=[#7,#8,#15,#16])]([#6])[CX4;!$(C(N)(N)[!#6])][NX3v3;!$(NC=[#7,#8,#15,#16])][#6]
# Ns are not part of an amide or similar. v3 ist to exclude nitro and similar groups

Hemiaminal: [NX3v3;!$(NC=[#7,#8,#15,#16])]([#6])[CX4;!$(C(N)(N)[!#6])][OX2H]

Thioacetal: [SX2]([#6;!$(C=[O,S,N])])[CX4;!$(C(S)(S)[!#6])][SX2][#6;!$(C=[O,S,N])]

Thiohemiacetal: [SX2]([#6;!$(C=[O,S,N])])[CX4;!$(C(S)(S)[!#6])][OX2H]

Halogen_acetal_like: [NX3v3,SX2,OX2;!$(*C=[#7,#8,#15,#16])][CX4;!$(C([N,S,O])([N,S,O])[!#6])][FX1,ClX1,BrX1,IX1]
# hits chloromethylenethers and other reactive alkylating agents

Acetal_like: [NX3v3,SX2,OX2;!$(*C=[#7,#8,#15,#16])][CX4;!$(C([N,S,O])([N,S,O])[!#6])][FX1,ClX1,BrX1,IX1,NX3v3,SX2,OX2;!$(*C=[#7,#8,#15,#16])]
# includes all of the above and other combinations (S-C-N, hydrates, ...), but still no aminomethylenesters and similar

Halogenmethylen_ester_and_similar: [NX3v3,SX2,OX2;$(**=[#7,#8,#15,#16])][CX4;!$(C([N,S,O])([N,S,O])[!#6])][FX1,ClX1,BrX1,IX1]
# also reactive alkylating agents. Acid does not have to be carboxylic acid, also S- and P-based acids allowed

NOS_methylen_ester_and_similar: [NX3v3,SX2,OX2;$(**=[#7,#8,#15,#16])][CX4;!$(C([N,S,O])([N,S,O])[!#6])][NX3v3,SX2,OX2;!$(*C=[#7,#8,#15,#16])]
# Same as above, but N,O or S instead of halogen. Ester/amide allowed only on one side

Hetero_methylen_ester_and_similar: [NX3v3,SX2,OX2;$(**=[#7,#8,#15,#16])][CX4;!$(C([N,S,O])([N,S,O])[!#6])][FX1,ClX1,BrX1,IX1,NX3v3,SX2,OX2;!$(*C=[#7,#8,#15,#16])]
# Combination of the last two patterns

Cyanhydrine: [NX1]#[CX2][CX4;$([CH2]),$([CH]([CX2])[#6]),$(C([CX2])([#6])[#6])][OX2H]


# I.3.3 Single Bond to Hetero, C=C Double Bond (Enols and Similar)

Chloroalkene: [ClX1][CX3]=[CX3]

Fluoroalkene: [FX1][CX3]=[CX3]

Bromoalkene: [BrX1][CX3]=[CX3]

Iodoalkene: [IX1][CX3]=[CX3]

Enol: [OX2H][CX3;$([H1]),$(C[#6])]=[CX3]
# no phenols

Endiol: [OX2H][CX3;$([H1]),$(C[#6])]=[CX3;$([H1]),$(C[#6])][OX2H]
# no 1,2-diphenols, ketenacetals, ...

Enolether: [OX2]([#6;!$(C=[N,O,S])])[CX3;$([H0][#6]),$([H1])]=[CX3]
# finds also endiodiethers, but not enolesters, no aromats

Enolester: [OX2]([CX3]=[OX1])[#6X3;$([#6][#6]),$([H1])]=[#6X3;!$(C[OX2H])]


Enamine: [NX3;$([NH2][CX3]),$([NH1]([CX3])[#6]),$([N]([CX3])([#6])[#6]);!$([N]*=[#7,#8,#15,#16])][CX3;$([CH]),$([C][#6])]=[CX3]
# does not hit amines attached to aromatic rings, nor may the nitrogen be aromatic

Thioenol: [SX2H][CX3;$([H1]),$(C[#6])]=[CX3]

Thioenolether: [SX2]([#6;!$(C=[N,O,S])])[CX3;$(C[#6]),$([CH])]=[CX3]


# I.4: Three Carbon-Hetero Bonds (Carboxyl and Derivatives)
# ------------------------------

Acylchloride: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[ClX1]

Acylfluoride: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[FX1]

Acylbromide: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[BrX1]

Acyliodide: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[IX1]

Acylhalide: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[FX1,ClX1,BrX1,IX1]
# all of the above


# The following contains all simple carboxylic combinations of O, N, S, & Hal -
# - acids, esters, amides, ... as well as a few extra cases (anhydride, hydrazide...)
# Cyclic structures (including aromats) like lactones, lactames, ... got their own
# definitions. Structures where both heteroatoms are part of an aromatic ring
# (oxazoles, imidazoles, ...) were excluded.

Carboxylic_acid: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[$([OX2H]),$([OX1-])]
# includes carboxylate anions

Carboxylic_ester:  [CX3;$([R0][#6]),$([H1R0])](=[OX1])[OX2][#6;!$(C=[O,N,S])]
# does not hit anhydrides or lactones

Lactone: [#6][#6X3R](=[OX1])[#8X2][#6;!$(C=[O,N,S])]
# may also be aromatic

Carboxylic_anhydride: [CX3;$([H0][#6]),$([H1])](=[OX1])[#8X2][CX3;$([H0][#6]),$([H1])](=[OX1])
# anhydride formed by two carboxylic acids, no mixed anhydrides (e.g. between carboxylic acid and sulfuric acid); may be part of a ring, even aromatic

Carboxylic_acid_derivative: [$([#6X3H0][#6]),$([#6X3H])](=[!#6])[!#6]
# includes most of the structures of I.4 and many more, also 1,3-heteroaromatics such as isoxazole

Carbothioic_acid: [CX3;!R;$([C][#6]),$([CH]);$([C](=[OX1])[$([SX2H]),$([SX1-])]),$([C](=[SX1])[$([OX2H]),$([OX1-])])]
# hits both tautomeric forms, as well as anions

Carbothioic_S_ester: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[SX2][#6;!$(C=[O,N,S])]

Carbothioic_S_lactone: [#6][#6X3R](=[OX1])[#16X2][#6;!$(C=[O,N,S])]
# may also be aromatic

Carbothioic_O_ester: [CX3;$([H0][#6]),$([H1])](=[SX1])[OX2][#6;!$(C=[O,N,S])]

Carbothioic_O_lactone: [#6][#6X3R](=[SX1])[#8X2][#6;!$(C=[O,N,S])]

Carbothioic_halide: [CX3;$([H0][#6]),$([H1])](=[SX1])[FX1,ClX1,BrX1,IX1]

Carbodithioic_acid: [CX3;!R;$([C][#6]),$([CH]);$([C](=[SX1])[SX2H])]

Carbodithioic_ester: [CX3;!R;$([C][#6]),$([CH]);$([C](=[SX1])[SX2][#6;!$(C=[O,N,S])])]

Carbodithiolactone: [#6][#6X3R](=[SX1])[#16X2][#6;!$(C=[O,N,S])]


Amide: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]
# does not hit lactames

Primary_amide: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[NX3H2]

Secondary_amide: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[#7X3H1][#6;!$(C=[O,N,S])]

Tertiary_amide: [CX3;$([R0][#6]),$([H1R0])](=[OX1])[#7X3H0]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])]

Lactam: [#6R][#6X3R](=[OX1])[#7X3;$([H1][#6;!$(C=[O,N,S])]),$([H0]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]
# cyclic amides, may also be aromatic

Alkyl_imide: [#6X3;$([H0][#6]),$([H1])](=[OX1])[#7X3H0]([#6])[#6X3;$([H0][#6]),$([H1])](=[OX1])
# may be part of a ring, even aromatic. only C allowed at central N. May also be triacyl amide

N_hetero_imide: [#6X3;$([H0][#6]),$([H1])](=[OX1])[#7X3H0]([!#6])[#6X3;$([H0][#6]),$([H1])](=[OX1])
# everything else than H or C at central N

Imide_acidic: [#6X3;$([H0][#6]),$([H1])](=[OX1])[#7X3H1][#6X3;$([H0][#6]),$([H1])](=[OX1])
# can be deprotonated

Thioamide: [$([CX3;!R][#6]),$([CX3H;!R])](=[SX1])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]
# does not hit thiolactames

Thiolactam: [#6R][#6X3R](=[SX1])[#7X3;$([H1][#6;!$(C=[O,N,S])]),$([H0]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]
# cyclic thioamides, may also be aromatic


Oximester: [#6X3;$([H0][#6]),$([H1])](=[OX1])[#8X2][#7X2]=,:[#6X3;$([H0]([#6])[#6]),$([H1][#6]),$([H2])]
# may also be part of a ring / aromatic

Amidine: [NX3;!$(NC=[O,S])][CX3;$([CH]),$([C][#6])]=[NX2;!$(NC=[O,S])]
# only basic amidines, not as part of aromatic ring (e.g. imidazole)

Hydroxamic_acid: [CX3;$([H0][#6]),$([H1])](=[OX1])[#7X3;$([H1]),$([H0][#6;!$(C=[O,N,S])])][$([OX2H]),$([OX1-])]

Hydroxamic_acid_ester: [CX3;$([H0][#6]),$([H1])](=[OX1])[#7X3;$([H1]),$([H0][#6;!$(C=[O,N,S])])][OX2][#6;!$(C=[O,N,S])]
# does not hit anhydrides of carboxylic acids withs hydroxamic acids


Imidoacid: [CX3R0;$([H0][#6]),$([H1])](=[NX2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[$([OX2H]),$([OX1-])]
# not cyclic

Imidoacid_cyclic: [#6R][#6X3R](=,:[#7X2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[$([OX2H]),$([OX1-])]
# the enamide-form of lactames. may be aromatic like 2-hydroxypyridine

Imidoester: [CX3R0;$([H0][#6]),$([H1])](=[NX2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[OX2][#6;!$(C=[O,N,S])]
# esters of the above structures. no anhydrides.

Imidolactone: [#6R][#6X3R](=,:[#7X2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[OX2][#6;!$(C=[O,N,S])]
# no oxazoles and similar

Imidothioacid: [CX3R0;$([H0][#6]),$([H1])](=[NX2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[$([SX2H]),$([SX1-])]
# not cyclic

Imidothioacid_cyclic: [#6R][#6X3R](=,:[#7X2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[$([SX2H]),$([SX1-])]
# the enamide-form of thiolactames. may be aromatic like 2-thiopyridine

Imidothioester: [CX3R0;$([H0][#6]),$([H1])](=[NX2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[SX2][#6;!$(C=[O,N,S])]
# thioesters of the above structures. no anhydrides.

Imidothiolactone: [#6R][#6X3R](=,:[#7X2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[SX2][#6;!$(C=[O,N,S])]
# no thioxazoles and similar

Amidine: [#7X3v3;!$(N([#6X3]=[#7X2])C=[O,S])][CX3R0;$([H1]),$([H0][#6])]=[NX2v3;!$(N(=[#6X3][#7X3])C=[O,S])]
# only basic amidines, not substituted by carbonyl or thiocarbonyl, not as part of a ring

Imidolactam: [#6][#6X3R;$([H0](=[NX2;!$(N(=[#6X3][#7X3])C=[O,S])])[#7X3;!$(N([#6X3]=[#7X2])C=[O,S])]),$([H0](-[NX3;!$(N([#6X3]=[#7X2])C=[O,S])])=,:[#7X2;!$(N(=[#6X3][#7X3])C=[O,S])])]
# one of the two C~N bonds is part of a ring (may be aromatic), but not both - thus no imidazole

Imidoylhalide: [CX3R0;$([H0][#6]),$([H1])](=[NX2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[FX1,ClX1,BrX1,IX1]
# not cyclic

Imidoylhalide_cyclic: [#6R][#6X3R](=,:[#7X2;$([H1]),$([H0][#6;!$(C=[O,N,S])])])[FX1,ClX1,BrX1,IX1]
# may also be aromatic

# may be ring, aromatic, substituted with carbonyls, hetero, ...
# (everything else would get too complicated)

Amidrazone: [$([$([#6X3][#6]),$([#6X3H])](=[#7X2v3])[#7X3v3][#7X3v3]),$([$([#6X3][#6]),$([#6X3H])]([#7X3v3])=[#7X2v3][#7X3v3])]
# hits both tautomers. as above, it may be ring, aromatic, substituted with carbonyls, hetero, ...


Alpha_aminoacid: [NX3,NX4+;!$([N]~[!#6]);!$([N]*~[#7,#8,#15,#16])][C][CX3](=[OX1])[OX2H,OX1-]
# N may be alkylated, but not part of an amide (as in peptides), ionic forms are included
# includes also non-natural aminoacids with double-bonded or two aliph./arom. substituents at alpha-C
# N may not be aromatic as in 1H-pyrrole-2-carboxylic acid

Alpha_hydroxyacid: [OX2H][C][CX3](=[OX1])[OX2H,OX1-]

Peptide_middle: [NX3;$([N][CX3](=[OX1])[C][NX3,NX4+])][C][CX3](=[OX1])[NX3;$([N][C][CX3](=[OX1])[NX3,OX2,OX1-])]
# finds peptidic structures which are neither C- nor N-terminal. Both neighbours must be amino-acids/peptides

Peptide_C_term: [NX3;$([N][CX3](=[OX1])[C][NX3,NX4+])][C][CX3](=[OX1])[OX2H,OX1-]
# finds C-terminal amino acids

Peptide_N_term: [NX3,NX4+;!$([N]~[!#6]);!$([N]*~[#7,#8,#15,#16])][C][CX3](=[OX1])[NX3;$([N][C][CX3](=[OX1])[NX3,OX2,OX1-])]
# finds N-terminal amino acids. As above, N may be substituted, but not part of an amide-bond.


Carboxylic_orthoester: [#6][OX2][CX4;$(C[#6]),$([CH])]([OX2][#6])[OX2][#6]
# hits also anhydride like struktures (e. g. HC(OMe)2-OC=O residues)

Ketene: [CX3]=[CX2]=[OX1]

Ketenacetal: [#7X2,#8X3,#16X2;$(*[#6,#14])][#6X3]([#7X2,#8X3,#16X2;$(*[#6,#14])])=[#6X3]
# includes aminals, silylacetals, ketenesters, etc. C=C DB is not aromatic, everything else may be

Nitrile: [NX1]#[CX2]
# includes cyanhydrines

Isonitrile: [CX1-]#[NX2+]


Vinylogous_carbonyl_or_carboxyl_derivative: [#6X3](=[OX1])[#6X3]=,:[#6X3][#7,#8,#16,F,Cl,Br,I]
# may be part of a ring, even aromatic

Vinylogous_acid: [#6X3](=[OX1])[#6X3]=,:[#6X3][$([OX2H]),$([OX1-])]

Vinylogous_ester: [#6X3](=[OX1])[#6X3]=,:[#6X3][#6;!$(C=[O,N,S])]

Vinylogous_amide: [#6X3](=[OX1])[#6X3]=,:[#6X3][#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Vinylogous_halide: [#6X3](=[OX1])[#6X3]=,:[#6X3][FX1,ClX1,BrX1,IX1]



# I.5: Four Carbon-Hetero Bonds (Carbonic Acid and Derivatives)
# -----------------------------

Carbonic_acid_dieester: [#6;!$(C=[O,N,S])][#8X2][#6X3](=[OX1])[#8X2][#6;!$(C=[O,N,S])]
# may be part of a ring, even aromatic

Carbonic_acid_esterhalide: [#6;!$(C=[O,N,S])][OX2;!R][CX3](=[OX1])[OX2][FX1,ClX1,BrX1,IX1]

Carbonic_acid_monoester: [#6;!$(C=[O,N,S])][OX2;!R][CX3](=[OX1])[$([OX2H]),$([OX1-])]
# unstable

Carbonic_acid_derivatives: [!#6][#6X3](=[!#6])[!#6]


Thiocarbonic_acid_dieester: [#6;!$(C=[O,N,S])][#8X2][#6X3](=[SX1])[#8X2][#6;!$(C=[O,N,S])]
# may be part of a ring, even aromatic

Thiocarbonic_acid_esterhalide: [#6;!$(C=[O,N,S])][OX2;!R][CX3](=[SX1])[OX2][FX1,ClX1,BrX1,IX1]

Thiocarbonic_acid_monoester: [#6;!$(C=[O,N,S])][OX2;!R][CX3](=[SX1])[$([OX2H]),$([OX1-])]


Urea:[#7X3;!$([#7][!#6])][#6X3](=[OX1])[#7X3;!$([#7][!#6])]
# no check whether part of imide, biuret, etc. Aromatic structures are only hit if
# both N share no double bonds, like in the dioxo-form of uracil

Thiourea: [#7X3;!$([#7][!#6])][#6X3](=[SX1])[#7X3;!$([#7][!#6])]

Isourea: [#7X2;!$([#7][!#6])]=,:[#6X3]([#8X2&!$([#8][!#6]),OX1-])[#7X3;!$([#7][!#6])]
# O may be substituted. no check whether further amide-like bonds are present. Aromatic
# structures are only hit if single bonded N shares no additional double bond, like in
# the 1-hydroxy-3-oxo form of uracil

Isothiourea: [#7X2;!$([#7][!#6])]=,:[#6X3]([#16X2&!$([#16][!#6]),SX1-])[#7X3;!$([#7][!#6])]

Guanidine: [N;v3X3,v4X4+][CX3](=[N;v3X2,v4X3+])[N;v3X3,v4X4+]
# also hits guanidinium salts. v3 and v4 to avoid nitroamidines

Carbaminic_acid: [NX3]C(=[OX1])[O;X2H,X1-]
# quite unstable, unlikely to be found. Also hits salts

Urethan: [#7X3][#6](=[OX1])[#8X2][#6]
# also hits when part of a ring, no check whether the last C is part of carbonyl

Biuret: [#7X3][#6](=[OX1])[#7X3][#6](=[OX1])[#7X3]

Semicarbazide: [#7X3][#7X3][#6X3]([#7X3;!$([#7][#7])])=[OX1]

Carbazide: [#7X3][#7X3][#6X3]([#7X3][#7X3])=[OX1]

Semicarbazone: [#7X2](=[#6])[#7X3][#6X3]([#7X3;!$([#7][#7])])=[OX1]

Carbazone: [#7X2](=[#6])[#7X3][#6X3]([#7X3][#7X3])=[OX1]

Thiosemicarbazide: [#7X3][#7X3][#6X3]([#7X3;!$([#7][#7])])=[SX1]

Thiocarbazide: [#7X3][#7X3][#6X3]([#7X3][#7X3])=[SX1]

Thiosemicarbazone: [#7X2](=[#6])[#7X3][#6X3]([#7X3;!$([#7][#7])])=[SX1]

Thiocarbazone: [#7X2](=[#6])[#7X3][#6X3]([#7X3][#7X3])=[SX1]


Isocyanate: [NX2]=[CX2]=[OX1]

Cyanate: [OX2][CX2]#[NX1]

Isothiocyanate: [NX2]=[CX2]=[SX1]

Thiocyanate: [SX2][CX2]#[NX1]

Carbodiimide: [NX2]=[CX2]=[NX2]

Orthocarbonic_derivatives: [CX4H0]([O,S,#7])([O,S,#7])([O,S,#7])[O,S,#7,F,Cl,Br,I]
# halogen allowed just once, to avoid mapping to -OCF3 and similar groups (much more
# stable as for example C(OCH3)4)


# I.6 Aromatics
# -------------

# I know that this classification is not very logical, arylamines are found under I.2 ...

Phenol: [OX2H][c]

1,2-Diphenol: [OX2H][c][c][OX2H]

Arylchloride: [Cl][c]

Arylfluoride: [F][c]

Arylbromide: [Br][c]

Aryliodide: [I][c]

Arylthiol: [SX2H][c]

Iminoarene: [c]=[NX2;$([H1]),$([H0][#6;!$([C]=[N,S,O])])]
# N may be substituted with H or C, but not carbonyl or similar
# aromatic atom is always C, not S or P (these are not planar when substituted)

Oxoarene: [c]=[OX1]

Thioarene: [c]=[SX1]

Hetero_N_basic_H: [nX3H1+0]
# as in pyrole. uncharged to exclude pyridinium ions

Hetero_N_basic_no_H: [nX3H0+0]
# as in N-methylpyrole. uncharged to exclude pyridinium ions

Hetero_N_nonbasic: [nX2,nX3+]
# as in pyridine, pyridinium

Hetero_O: [o]

Hetero_S: [sX2]
# X2 because Daylight's depictmatch falsely describes C1=CS(=O)C=C1 as aromatic
# (is not planar because of lonepair at S)

Heteroaromatic: [a;!c]


# Part II: N, S, P, Si, B
# =======================


# II.1 Nitrogen
# -------------

Nitrite: [NX2](=[OX1])[O;$([X2]),$([X1-])]
# hits nitrous acid, its anion, esters, and other O-substituted derivatives

Thionitrite: [SX2][NX2]=[OX1]

Nitrate: [$([NX3](=[OX1])(=[OX1])[O;$([X2]),$([X1-])]),$([NX3+]([OX1-])(=[OX1])[O;$([X2]),$([X1-])])]
# hits nitric acid, its anion, esters, and other O-substituted derivatives

Nitro: [$([NX3](=O)=O),$([NX3+](=O)[O-])][!#8]
# hits nitro groups attached to C,N, ... but not nitrates

Nitroso: [NX2](=[OX1])[!#7;!#8]
# no nitrites, no nitrosamines

Azide: [NX1]~[NX2]~[NX2,NX1]
# hits both mesomeric forms, also anion

Acylazide: [CX3](=[OX1])[NX2]~[NX2]~[NX1]

Diazo: [$([#6]=[NX2+]=[NX1-]),$([#6-]-[NX2+]#[NX1])]

Diazonium: [#6][NX2+]#[NX1]

Nitrosamine: [#7;!$(N*=O)][NX2]=[OX1]

Nitrosamide: [NX2](=[OX1])N-*=O
# includes nitrososulfonamides

N-Oxide: [$([#7+][OX1-]),$([#7v5]=[OX1]);!$([#7](~[O])~[O]);!$([#7]=[#7])]
# Hits both forms. Won't hit azoxy, nitro, nitroso, or nitrate.


Hydrazine: [NX3;$([H2]),$([H1][#6]),$([H0]([#6])[#6]);!$(NC=[O,N,S])][NX3;$([H2]),$([H1][#6]),$([H0]([#6])[#6]);!$(NC=[O,N,S])]
# no hydrazides

Hydrazone: [NX3;$([H2]),$([H1][#6]),$([H0]([#6])[#6]);!$(NC=[O,N,S])][NX2]=[#6]

Hydroxylamine: [NX3;$([H2]),$([H1][#6]),$([H0]([#6])[#6]);!$(NC=[O,N,S])][OX2;$([H1]),$(O[#6;!$(C=[N,O,S])])]
# no discrimination between O-, N-, and O,N-substitution


# II.2 Sulfur
# -----------

Sulfon: [$([SX4](=[OX1])(=[OX1])([#6])[#6]),$([SX4+2]([OX1-])([OX1-])([#6])[#6])]
# can't be aromatic, thus S and not #16

Sulfoxide: [$([SX3](=[OX1])([#6])[#6]),$([SX3+]([OX1-])([#6])[#6])]

Sulfonium: [S+;!$([S]~[!#6]);!$([S]*~[#7,#8,#15,#16])]
# can't be aromatic, thus S and not #16

Sulfuric_acid: [SX4](=[OX1])(=[OX1])([$([OX2H]),$([OX1-])])[$([OX2H]),$([OX1-])]
# includes anions

Sulfuric_monoester: [SX4](=[OX1])(=[OX1])([$([OX2H]),$([OX1-])])[OX2][#6;!$(C=[O,N,S])]

Sulfuric_diester: [SX4](=[OX1])(=[OX1])([OX2][#6;!$(C=[O,N,S])])[OX2][#6;!$(C=[O,N,S])]

Sulfuric_monoamide: [SX4](=[OX1])(=[OX1])([#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])])[$([OX2H]),$([OX1-])]

Sulfuric_diamide: [SX4](=[OX1])(=[OX1])([#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Sulfuric_esteramide: [SX4](=[OX1])(=[OX1])([#7X3][#6;!$(C=[O,N,S])])[OX2][#6;!$(C=[O,N,S])]

Sulfuric_derivative: [SX4D4](=[!#6])(=[!#6])([!#6])[!#6]
# everything else (would not be a "true" derivative of sulfuric acid, if one of the substituents were less electronegative
# than sulfur, but this should be very very rare, anyway)



#### sulfurous acid and derivatives missing!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!




Sulfonic_acid: [SX4;$([H1]),$([H0][#6])](=[OX1])(=[OX1])[$([OX2H]),$([OX1-])]

Sulfonamide: [SX4;$([H1]),$([H0][#6])](=[OX1])(=[OX1])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Sulfonic_ester: [SX4;$([H1]),$([H0][#6])](=[OX1])(=[OX1])[OX2][#6;!$(C=[O,N,S])]

Sulfonic_halide: [SX4;$([H1]),$([H0][#6])](=[OX1])(=[OX1])[FX1,ClX1,BrX1,IX1]

Sulfonic_derivative: [SX4;$([H1]),$([H0][#6])](=[!#6])(=[!#6])[!#6]
# includes all of the above and many more
# for comparison: this is what "all sulfonic derivatives but not the ones above" would look like:
# [$([SX4;$([H1]),$([H0][#6])](=[!#6])(=[!#6;!O])[!#6]),$([SX4;$([H1]),$([H0][#6])](=[OX1])(=[OX1])[!$([FX1,ClX1,BrX1,IX1]);!$([#6]);!$([OX2H]);!$([OX1-]);!$([OX2][#6;!$(C=[O,N,S])]);!$([#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])])])]


Sulfinic_acid: [SX3;$([H1]),$([H0][#6])](=[OX1])[$([OX2H]),$([OX1-])]

Sulfinic_amide: [SX3;$([H1]),$([H0][#6])](=[OX1])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Sulfinic_ester: [SX3;$([H1]),$([H0][#6])](=[OX1])[OX2][#6;!$(C=[O,N,S])]

Sulfinic_halide: [SX3;$([H1]),$([H0][#6])](=[OX1])[FX1,ClX1,BrX1,IX1]

Sulfinic_derivative: [SX3;$([H1]),$([H0][#6])](=[!#6])[!#6]

Sulfenic_acid: [SX2;$([H1]),$([H0][#6])][$([OX2H]),$([OX1-])]

Sulfenic_amide: [SX2;$([H1]),$([H0][#6])][#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Sulfenic_ester: [SX2;$([H1]),$([H0][#6])][OX2][#6;!$(C=[O,N,S])]

Sulfenic_halide: [SX2;$([H1]),$([H0][#6])][FX1,ClX1,BrX1,IX1]

Sulfenic_derivative: [SX2;$([H1]),$([H0][#6])][!#6]


# II.3 Phosphorous
# ----------------

Phosphine: [PX3;$([H3]),$([H2][#6]),$([H1]([#6])[#6]),$([H0]([#6])([#6])[#6])]
# similar to amine, but less restrictive: includes also amide- and aminal-analogues

Phosphine_oxide: [PX4;$([H3]=[OX1]),$([H2](=[OX1])[#6]),$([H1](=[OX1])([#6])[#6]),$([H0](=[OX1])([#6])([#6])[#6])]

Phosphonium: [P+;!$([P]~[!#6]);!$([P]*~[#7,#8,#15,#16])]
# similar to Ammonium

Phosphorylen: [PX4;$([H3]=[CX3]),$([H2](=[CX3])[#6]),$([H1](=[CX3])([#6])[#6]),$([H0](=[CX3])([#6])([#6])[#6])]


# conventions for the following acids and derivatives:
# acids find protonated and deprotonated acids
# esters do not find mixed anhydrides ( ...P-O-C(=O))
# derivatives: subtituents which go in place of the OH and =O are not H or C (may also be O,
# thus including acids and esters)

Phosphonic_acid: [PX4;$([H1]),$([H0][#6])](=[OX1])([$([OX2H]),$([OX1-])])[$([OX2H]),$([OX1-])]
# includes anions

Phosphonic_monoester: [PX4;$([H1]),$([H0][#6])](=[OX1])([$([OX2H]),$([OX1-])])[OX2][#6;!$(C=[O,N,S])]

Phosphonic_diester: [PX4;$([H1]),$([H0][#6])](=[OX1])([OX2][#6;!$(C=[O,N,S])])[OX2][#6;!$(C=[O,N,S])]

Phosphonic_monoamide: [PX4;$([H1]),$([H0][#6])](=[OX1])([$([OX2H]),$([OX1-])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphonic_diamide: [PX4;$([H1]),$([H0][#6])](=[OX1])([#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphonic_esteramide: [PX4;$([H1]),$([H0][#6])](=[OX1])([OX2][#6;!$(C=[O,N,S])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphonic_acid_derivative: [PX4;$([H1]),$([H0][#6])](=[!#6])([!#6])[!#6]
# all of the above and much more


Phosphoric_acid: [PX4D4](=[OX1])([$([OX2H]),$([OX1-])])([$([OX2H]),$([OX1-])])[$([OX2H]),$([OX1-])]
# includes anions

Phosphoric_monoester: [PX4D4](=[OX1])([$([OX2H]),$([OX1-])])([$([OX2H]),$([OX1-])])[OX2][#6;!$(C=[O,N,S])]

Phosphoric_diester: [PX4D4](=[OX1])([$([OX2H]),$([OX1-])])([OX2][#6;!$(C=[O,N,S])])[OX2][#6;!$(C=[O,N,S])]

Phosphoric_triester: [PX4D4](=[OX1])([OX2][#6;!$(C=[O,N,S])])([OX2][#6;!$(C=[O,N,S])])[OX2][#6;!$(C=[O,N,S])]

Phosphoric_monoamide: [PX4D4](=[OX1])([$([OX2H]),$([OX1-])])([$([OX2H]),$([OX1-])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphoric_diamide: [PX4D4](=[OX1])([$([OX2H]),$([OX1-])])([#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphoric_triamide: [PX4D4](=[OX1])([#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])])([#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphoric_monoestermonoamide: [PX4D4](=[OX1])([$([OX2H]),$([OX1-])])([OX2][#6;!$(C=[O,N,S])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphoric_diestermonoamide: [PX4D4](=[OX1])([OX2][#6;!$(C=[O,N,S])])([OX2][#6;!$(C=[O,N,S])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphoric_monoesterdiamide: [PX4D4](=[OX1])([OX2][#6;!$(C=[O,N,S])])([#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphoric_acid_derivative: [PX4D4](=[!#6])([!#6])([!#6])[!#6]


Phosphinic_acid: [PX4;$([H2]),$([H1][#6]),$([H0]([#6])[#6])](=[OX1])[$([OX2H]),$([OX1-])]

Phosphinic_ester: [PX4;$([H2]),$([H1][#6]),$([H0]([#6])[#6])](=[OX1])[OX2][#6;!$(C=[O,N,S])]

Phosphinic_amide: [PX4;$([H2]),$([H1][#6]),$([H0]([#6])[#6])](=[OX1])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphinic_acid_derivative: [PX4;$([H2]),$([H1][#6]),$([H0]([#6])[#6])](=[!#6])[!#6]


Phosphonous_acid: [PX3;$([H1]),$([H0][#6])]([$([OX2H]),$([OX1-])])[$([OX2H]),$([OX1-])]

Phosphonous_monoester: [PX3;$([H1]),$([H0][#6])]([$([OX2H]),$([OX1-])])[OX2][#6;!$(C=[O,N,S])]

Phosphonous_diester: [PX3;$([H1]),$([H0][#6])]([OX2][#6;!$(C=[O,N,S])])[OX2][#6;!$(C=[O,N,S])]

Phosphonous_monoamide: [PX3;$([H1]),$([H0][#6])]([$([OX2H]),$([OX1-])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphonous_diamide: [PX3;$([H1]),$([H0][#6])]([#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphonous_esteramide: [PX3;$([H1]),$([H0][#6])]([OX2][#6;!$(C=[O,N,S])])[#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphonous_derivatives: [PX3;$([D2]),$([D3][#6])]([!#6])[!#6]


Phosphinous_acid: [PX3;$([H2]),$([H1][#6]),$([H0]([#6])[#6])][$([OX2H]),$([OX1-])]

Phosphinous_ester: [PX3;$([H2]),$([H1][#6]),$([H0]([#6])[#6])][OX2][#6;!$(C=[O,N,S])]

Phosphinous_amide: [PX3;$([H2]),$([H1][#6]),$([H0]([#6])[#6])][#7X3;$([H2]),$([H1][#6;!$(C=[O,N,S])]),$([#7]([#6;!$(C=[O,N,S])])[#6;!$(C=[O,N,S])])]

Phosphinous_derivatives: [PX3;$([H2]),$([H1][#6]),$([H0]([#6])[#6])][!#6]


# II.4 Silicon
# ------------

Quart_silane: [SiX4]([#6])([#6])([#6])[#6]
# four C-substituents. non-reactive, non-toxic, in experimental phase for drug development

Non-quart_silane: [SiX4;$([H1]([#6])([#6])[#6]),$([H2]([#6])[#6]),$([H3][#6]),$([H4])]
# has 1-4 hydride(s), reactive. Daylight's depictmatch does not add hydrogens automatically to
# the free positions at Si, thus Hs had to be added implicitly

Silylmonohalide: [SiX4]([FX1,ClX1,BrX1,IX1])([#6])([#6])[#6]
# reagents for inserting protection groups

Het_trialkylsilane: [SiX4]([!#6])([#6])([#6])[#6]
# mostly acid-labile protection groups such as trimethylsilyl-ethers

Dihet_dialkylsilane: [SiX4]([!#6])([!#6])([#6])[#6]

Trihet_alkylsilane: [SiX4]([!#6])([!#6])([!#6])[#6]

Silicic_acid_derivative: [SiX4]([!#6])([!#6])([!#6])[!#6]
# four substituent which are neither C nor H


# II.5 Boron
# ----------

Trialkylborane: [BX3]([#6])([#6])[#6]
# also carbonyls allowed

Boric_acid_derivatives: [BX3]([!#6])([!#6])[!#6]
# includes acids, esters, amides, ... H-substituent at B is very rare.

Boronic_acid_derivative: [BX3]([!#6])([!#6])[!#6]
# # includes acids, esters, amides, ...

Borohydride: [BH1,BH2,BH3,BH4]
# at least one H attached to B

Quaternary_boron: [BX4]
# mostly borates (negative charge), in complex with Lewis-base



# Part III: Some Special Patterns
# ===============================


# III.1 Chains
# ------------

# some simple chains



# III.2 Rings
# -----------

Aromatic: a

Heterocyclic: [!#6;!R0]
# may be aromatic or not

Epoxide: [OX2r3]1[#6r3][#6r3]1
# toxic/reactive. may be annelated to aromat, but must not be aromatic itself (oxirane-2,3-dione)

NH_aziridine: [NX3H1r3]1[#6r3][#6r3]1
# toxic/reactive according to Maybridge's garbage filter

Spiro: [D4R;$(*(@*)(@*)(@*)@*)]
# at least two different rings can be found which are sharing just one atom.
# these two rings can be connected by a third ring, so it matches also some
# bridged systems, like morphine

Annelated_rings: [R;$(*(@*)(@*)@*);!$([R2;$(*(@*)(@*)(@*)@*)])]@[R;$(*(@*)(@*)@*);!$([R2;$(*(@*)(@*)(@*)@*)])]
# two different rings sharing exactly two atoms

Bridged_rings: [R;$(*(@*)(@*)@*);!$([D4R;$(*(@*)(@*)(@*)@*)]);!$([R;$(*(@*)(@*)@*);!$([R2;$(*(@*)(@*)(@*)@*)])]@[R;$(*(@*)(@*)@*);!$([R2;$(*(@*)(@*)(@*)@*)])])]
# part of two or more rings, not spiro, not annelated -> finds bridgehead atoms,
# but only if they are not annelated at the same time - otherwise impossible (?)
# to distinguish from non-bridgehead annelated atoms

# some basic ring-patterns (just size, no other information):





# III.3 Sugars and Nucleosides/Nucleotides, Steroids
# --------------------------------------------------

# because of the large variety of sugar derivatives, different patterns can be applied.
# The choice of patterns and their combinations will depend on the contents of the database
# e.g. natural products, nucleoside analoges with modified sugars, ... as well as on the
# desired restriction


Sugar_pattern_1: [OX2;$([r5]1@C@C@C(O)@C1),$([r6]1@C@C@C(O)@C(O)@C1)]
# 5 or 6-membered ring containing one O and at least one (r5) or two (r6) oxygen-substituents.

Sugar_pattern_2: [OX2;$([r5]1@C(!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C1),$([r6]1@C(!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C@C1)]
# 5 or 6-membered ring containing one O and an acetal-like bond at postion 2.

Sugar_pattern_combi: [OX2;$([r5]1@C(!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C(O)@C1),$([r6]1@C(!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C(O)@C(O)@C1)]
# combination of the two above

Sugar_pattern_2_reducing: [OX2;$([r5]1@C(!@[OX2H1])@C@C@C1),$([r6]1@C(!@[OX2H1])@C@C@C@C1)]
# 5 or 6-membered cyclic hemi-acetal

Sugar_pattern_2_alpha: [OX2;$([r5]1@[C@@](!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C1),$([r6]1@[C@@](!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C@C1)]
# 5 or 6-membered cyclic hemi-acetal

Sugar_pattern_2_beta: [OX2;$([r5]1@[C@](!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C1),$([r6]1@[C@](!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C@C1)]
# 5 or 6-membered cyclic hemi-acetal

##Poly_sugar_1: ([OX2;$([r5]1@C@C@C(O)@C1),$([r6]1@C@C@C(O)@C(O)@C1)].[OX2;$([r5]1@C@C@C(O)@C1),$([r6]1@C@C@C(O)@C(O)@C1)])
# pattern1 occours more than once (in same molecule, but moieties don't have to be adjacent!)

##Poly_sugar_2: ([OX2;$([r5]1@C(!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C1),$([r6]1@C(!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C@C1)].[OX2;$([r5]1@C(!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C1),$([r6]1@C(!@[OX2,NX3,SX2,FX1,ClX1,BrX1,IX1])@C@C@C@C1)])
# pattern2 occours more than once (in same molecule, but moieties don't have to be adjacent!)


# III.4 Everything else...
# ------------------------

Conjugated_double_bond: *=*[*]=,#,:[*]

Conjugated_tripple_bond: *#*[*]=,#,:[*]

Cis_double_bond: */[D2]=[D2]\*
# only one single-bonded substituent on each DB-atom. no aromats.
# only found when character of DB is explicitely stated.

Trans_double_bond: */[D2]=[D2]/*
# analog

Mixed_anhydrides: [$(*=O),$([#16,#14,#5]),$([#7]([#6]=[OX1]))][#8X2][$(*=O),$([#16,#14,#5]),$([#7]([#6]=[OX1]))]
# should hits all combinations of two acids

Halogen_on_hetero: [FX1,ClX1,BrX1,IX1][!#6]

Halogen_multi_subst: [F,Cl,Br,I;!$([X1]);!$([X0-])]
# Halogen which is not mono-substituted nor an anion, e.g. chlorate.
# Most of these cases should be also filtered by Halogen_on_hetero.

Trifluoromethyl: [FX1][CX4;!$([H0][Cl,Br,I]);!$([F][C]([F])([F])[F])]([FX1])([FX1])
# C with three F attached, connected to anything which is not another halogen

C_ONS_bond: [#6]~[#7,#8,#16]
# probably all drug-like molecules have at least one O, N, or S connected to a C -> nice filter

## Mixture: (*).(*)
# two or more seperate parts, may also be salt
# component-level grouping is not yet supported in Open Babel Version 2.0


Charged: [!+0]

Anion: [-1,-2,-3,-4,-5,-6,-7]

Kation: [+1,+2,+3,+4,+5,+6,+7]

Salt: ([-1,-2,-3,-4,-5,-6,-7]).([+1,+2,+3,+4,+5,+6,+7])
# two or more seperate components with opposite charges

##Zwitterion: ([-1,-2,-3,-4,-5,-6,-7].[+1,+2,+3,+4,+5,+6,+7])
# both negative and positive charges somewhere within the same molecule.

1,3-Tautomerizable: [$([#7X2,OX1,SX1]=*[!H0;!$([a;!n])]),$([#7X3,OX2,SX2;!H0]*=*),$([#7X3,OX2,SX2;!H0]*:n)]
# 1,3 migration of H allowed. Includes keto/enol and amide/enamide.
# Aromatic rings must stay aromatic - no keto form of phenol

1,5-Tautomerizable: [$([#7X2,OX1,SX1]=,:**=,:*[!H0;!$([a;!n])]),$([#7X3,OX2,SX2;!H0]*=**=*),$([#7X3,OX2,SX2;!H0]*=,:**:n)]

Rotatable_bond: [!$(*#*)&!D1]-!@[!$(*#*)&!D1]
# taken from http://www.daylight.com/support/contrib/smarts/content.html

Michael_acceptor: [CX3]=[CX3][$([CX3]=[O,N,S]),$(C#[N]),$([S,P]=[OX1]),$([NX3]=O),$([NX3+](=O)[O-])]
# the classical case: C=C near carbonyl, nitrile, nitro, or similar
# Oxo-heteroaromats and similar are not included.

Dicarbodiazene: [CX3](=[OX1])[NX2]=[NX2][CX3](=[OX1])
# Michael-like acceptor, see Mitsunobu reaction

# H-Bond_donor:

# H-Bond_acceptor:

# Pos_ionizable:

# Neg_ionizable:

# Unlikely_ions:
# O+,N-,C+,C-, ...

CH-acidic: [$([CX4;!$([H0]);!$(C[!#6;!$([P,S]=O);!$(N(~O)~O)])][$([CX3]=[O,N,S]),$(C#[N]),$([S,P]=[OX1]),$([NX3]=O),$([NX3+](=O)[O-]);!$(*[S,O,N;H1,H2]);!$([*+0][S,O;X1-])]),$([CX4;!$([H0])]1[CX3]=[CX3][CX3]=[CX3]1)]
# C-H alpha to carbony, nitro or similar, C is not double-bonded, only C, H, S,P=O and nitro substituents allowed.
# pentadiene is included. acids, their salts, prim./sec. amides, and imides are excluded.
# hits also CH-acidic_strong

CH-acidic_strong: [CX4;!$([H0]);!$(C[!#6;!$([P,S]=O);!$(N(~O)~O)])]([$([CX3]=[O,N,S]),$(C#[N]),$([S,P]=[OX1]),$([NX3]=O),$([NX3+](=O)[O-]);!$(*[S,O,N;H1,H2]);!$([*+0][S,O;X1-])])[$([CX3]=[O,N,S]),$(C#[N]),$([S,P]=[OX1]),$([NX3]=O),$([NX3+](=O)[O-]);!$(*[S,O,N;H1,H2]);!$([*+0][S,O;X1-])]
# same as above (without pentadiene), but carbonyl or similar on two or three sides

Chiral_center_specified: [$([*@](~*)(~*)(*)*),$([*@H](*)(*)*),$([*@](~*)(*)*),$([*@H](~*)~*)]
# Hits atoms with tetrahedral chirality, if chiral center is specified in the SMILES string
# depictmach does not find oxonium, sulfonium, or sulfoxides!

# Chiral_center_unspecified: [$([*@?](~*)(~*)(*)*),$([*@?H](*)(*)*),$([*@?](~*)(*)*),$([*@?H](~*)~*)]
# Hits atoms with tetrahedral chirality, if chiral center is not specified in the SMILES string
# "@?" (unspecified chirality) is not yet supported in Open Babel Version 2.0
