List of Functional Groups Recognized by Checkmol

List of functional groups recognized by checkmol Current program version: v0.3c Norbert Haider, University of Vienna, 2005 http://merian.pch.univie.ac.at/~nhaider/cheminf/cmmm.html

No. functional group name code general structure remarks 001 cation 000000T2 any positive charge 002 anion 000000T1 any negative charge 003 carbonyl compound C2O10000 O ketone or aldehyde R1 = H, alkyl, aryl 2 1 2 R = H, alkyl, aryl R R 004 aldehyde C2O1H000 O R = H, alkyl, aryl

R H 005 ketone C2O1C000 O R1 = alkyl, aryl 2 1 2 R = alkyl, aryl R R 006 thiocarbonyl compound C2S10000 S thioketone or thioaldehyde R1 = H, alkyl, aryl 2 1 2 R = H, alkyl, aryl R R 007 thioaldehyde C2S1H000 S R = H, alkyl, aryl

R H 008 thioketone C2S1C000 S R1 = alkyl, aryl 2 1 2 R = alkyl, aryl R R 009 imine C2N10000 R3 N R1 = H, alkyl, aryl 2 1 2 R = H, alkyl, aryl R R 3 R = H, alkyl, aryl 010 hydrazone C2N1N000 R3

N 1 R4 R = H, alkyl, aryl N R2 = H, alkyl, aryl R3 = H, alkyl, aryl 1 2 R4 = H, alkyl, aryl R R 011 semicarbazone C2NNC4ON R4

O N R5

1 N 3 R = H, alkyl, aryl R 2 N R = H, alkyl, aryl R3 = H, alkyl, aryl 4 1 2 R = H, alkyl, aryl, R R 5 R = H, alkyl, aryl 012 thiosemicarbazone C2NNC4SN R4

S N R5

1 N 3 R = H, alkyl, aryl R 2 N R = H, alkyl, aryl R3 = H, alkyl, aryl 4 1 2 R = H, alkyl, aryl, R R 5 R = H, alkyl, aryl 013 oxime C2N1OH00 OH N R1 = H, alkyl, aryl 2 1 2 R = H, alkyl, aryl R R 014 oxime ether C2N1OC00 OR3 N R1 = H, alkyl, aryl 2 1 2 R = H, alkyl, aryl R R 3 R = alkyl, aryl 015 ketene C3OC0000 O

R1 = H, alkyl, aryl 2 1 2 R = H, alkyl, aryl R R 016 ketene acetal derivative C3OCC000 X Y R1 = H, alkyl, aryl R2 = H, alkyl, aryl X = any hetero atom R1 R2 Y = any hetero atom 017 carbonyl hydrate C2O2H200 HO OH R1 = H, alkyl, aryl 2 1 2 R = H, alkyl, aryl R R 018 hemiacetal C2O2HC00 3 R O OH R1 = H, alkyl, aryl 2 1 2 R = H, alkyl, aryl R R 3 R = alkyl, aryl 019 acetal C2O2CC00 R3O OR4 R1 = H, alkyl, aryl R2 = H, alkyl, aryl 3 R1 R2 R = alkyl, aryl 4 R = alkyl, aryl 4 3 020 hemiaminal C2NOHC10 R R1 = H, alkyl, aryl in a true hemiaminal, R would be H 2 R3O N R5 R = H, alkyl, aryl R3 = H, alkyl, aryl 1 2 R4 = H, alkyl, aryl R R 5 R = H, alkyl, aryl 1 021 aminal C2N2CC10 R4 R5 R = H, alkyl, aryl R2 = H, alkyl, aryl 3 6 R N N R R3 = H, alkyl, aryl R4 = H, alkyl, aryl 1 2 R R R5 = H, alkyl, aryl 6 R = H, alkyl, aryl 4 022 thiohemiaminal C2NSHC10 R R1 = H, alkyl, aryl 3 5 2 R S N R R = H, alkyl, aryl R3 = H, alkyl, aryl 1 2 R4 = H, alkyl, aryl R R 5 R = H, alkyl, aryl 023 thioacetal C2S2CC00 R3S SR4 R1 = H, alkyl, aryl R2 = H, alkyl, aryl 3 R1 R2 R = alkyl, aryl 4 R = alkyl, aryl 024 enamine C2CNH000 5 4 R4, R5 = acyl should be types as R R 1 N R = H, acyl, alkyl, aryl enamide R2 = H, acyl, alkyl, aryl 1 3 R 3 R = H, acyl, alkyl, aryl R R4 = H, acyl, alkyl, aryl R2 R5 = H, acyl, alkyl, aryl

025 enol C2COH000 OH 1 R1 = H, acyl, alkyl, aryl R R3 R2 = H, acyl, alkyl, aryl 3 2 R = H, acyl, alkyl, aryl R 026 enolether C2COC000 OR4 1 1 R = H, acyl, alkyl, aryl 2 R 3 R = H, acyl, alkyl, aryl R R3 = H, acyl, alkyl, aryl 2 R4 = alkyl, aryl R 027 hydroxy compound O1H00000 ROH R = alkyl, aryl alcohol or phenol

028 alcohol O1H0C000 ROH R = alkyl

029 prim. alcohol O1H1C000 R OH R = alkyl, aryl

030 sec. alcohol O1H2C000 R2 R1 = alkyl, aryl 1 R2 = alkyl, aryl R OH 031 tert. alcohol O1H3C000 2 R3 R R1 = alkyl, aryl 1 R OH R2 = alkyl, aryl 3 R = alkyl, aryl 032 1,2-diol O1H0CO1H HO OH R1 = H, alkyl, aryl 1 3 R2 = H, alkyl, aryl R R 2 4 R3 = H, alkyl, aryl R R 4 R = H, alkyl, aryl 1 033 1,2-aminoalcohol O1H0CN1C HO NH2 R = H, alkyl, aryl 1 3 R2 = H, alkyl, aryl R R 3 R2 R4 R = H, alkyl, aryl R4 = H, alkyl, aryl 034 phenol O1H1A000 OH any aromatic or heteroaromatic ring with an OH substituent

035 1,2-diphenol O1H2A000 OH any aromatic or heteroaromatic ring with two adjacent OH substituents (except tautomeric lactams) OH 036 enediol C2COH200 HO OH R1 = H, alkyl, aryl 2 1 2 R = H, alkyl, aryl R R 1 037 ether O1C00000 1 O 2 R = alkyl, aryl R R 2 R = alkyl, aryl 1 038 dialkylether O1C0CC00 1 O 2 R = alkyl R R 2 R = alkyl 1 039 alkylarylether O1C0CA00 1 O 2 R = alkyl R R 2 R = aryl 1 040 diarylether O1C0AA00 1 O 2 R = aryl R R 2 R = aryl 1 041 thioether S1C00000 1 S 2 R = alkyl, aryl R R 2 R = alkyl, aryl 042 disulfide S1S1C000 2 1 1 S R R = alkyl, aryl R S 2 R = alkyl, aryl 043 peroxide O1O1C000 2 1 1 O R R = alkyl, aryl R O 2 R = alkyl, aryl 044 hydroperoxide O1O1H000 O R = alkyl, aryl R OH 045 hydrazine derivative N1N10000 2 R R1 = H, acyl, alkyl, aryl 3 R2 = H, acyl, alkyl, aryl 1 N R R N R3 = H, acyl, alkyl, aryl 4 R4 = H, acyl, alkyl, aryl R 046 hydroxylamine N1O1H000 2 R R1 = H, alkyl, aryl 3 R2 = H, alkyl, aryl 1 N R 3 R O R = H, alkyl, aryl 3 047 amine N1C00000 R R1 = alkyl, aryl R2 = H, alkyl, aryl N 1 2 R3 = H, alkyl, aryl R R 048 prim. amine N1C10000 RNH R = alkyl, aryl 2 049 prim. aliphat. amine N1C1C000 RNH R = alkyl 2 050 prim. aromat. amine N1C1A000 RNH R = aryl 2 051 sec. amine N1C20000 H R1 = alkyl, aryl N 1 2 R2 = alkyl, aryl R R 052 sec. aliphat. amine N1C2CC00 H R1 = alkyl N 1 2 R2 = alkyl R R 053 sec. mixed amine (aryl alkyl) N1C2AC00 H R1 = alkyl N 1 2 R2 = aryl R R 054 sec. aromat. amine N1C2AA00 H R1 = aryl N 1 2 R2 = aryl R R 3 055 tert. amine N1C30000 R R1 = alkyl, aryl R2 = alkyl, aryl N 1 2 R3 = alkyl, aryl R R 3 056 tert. aliphat. amine N1C3CC00 R R1 = alkyl R2 = alkyl N 1 2 R3 = alkyl R R 3 057 tert. mixed amine N1C3AC00 R R1 = alkyl R2 = aryl N 1 2 R3 = alkyl, aryl R R 3 058 tert. arom_amine N1C3AA00 R R1 = aryl R2 = aryl N 1 2 R3 = aryl R R 059 quaternary ammonium salt N1C400T2 3 1 4 R R = alkyl, aryl R + R2 = alkyl, aryl N 3 R1 R2 R = alkyl, aryl 4 R = alkyl, aryl 060 N-oxide N0O10000 the N-O bond may be formulated as O a double bond O + 1 N + R = alkyl, aryl 2 1 N 3 R = alkyl, aryl R R 3 R2 R = alkyl, aryl

061 halogen deriv. XX000000 RX X = F, Cl, Br, I R = alkyl, alkenyl, aryl 062 alkyl halide XX00C000 RX X = F, Cl, Br, I R = alkyl 063 alkyl fluoride XF00C000 RF R = alkyl 064 alkyl chloride XC00C000 RCl R = alkyl 065 alkyl bromide XB00C000 RBr R = alkyl 066 alkyl iodide XI00C000 RI R = alkyl 067 aryl halide XX00A000 RX X = F, Cl, Br, I R = aryl 068 aryl fluoride XF00A000 RF R = aryl 069 aryl chloride XC00A000 RCl R = aryl 070 aryl bromide XB00A000 RBr R = aryl 071 aryl iodide XI00A000 RI R = aryl 072 organometallic compound 000000MX R M M = any metal R = alkyl, aryl 073 organolithium compound 000000ML RLi R = alkyl, aryl 074 organomagnesium compound 000000MM RMg R = alkyl, aryl 075 carboxylic acid deriv. C3O20000 O R = H, alkyl, aryl X = any hetero atom R X 076 carboxylic acid C3O2H000 O R = H, alkyl, aryl R OH 077 carboxylic acid salt C3O200T1 O R = H, alkyl, aryl R O 078 carboxylic acid ester C3O2C000 O 2 R1 = H, alkyl, aryl R 1 R2 = alkyl, aryl R O 079 lactone C3O2CZ00 O a cyclic ester (any ring size)

O

080 carboxylic acid amide C3ONC000 O 2 R1 = H, alkyl, aryl 1 R 2 R N R = H, alkyl, aryl 3 3 R = H, alkyl, aryl R 081 carboxylic acid prim. amide C3ONC100 O R = H, alkyl, aryl R NH 2 082 carboxylic acid sec. amide C3ONC200 O 2 R1 = H, alkyl, aryl 1 R 2 R N R = alkyl, aryl H 083 carboxylic acid tert. amide C3ONC300 O 2 R1 = H, alkyl, aryl 1 R 2 R N R = alkyl, aryl 3 3 R = alkyl, aryl R 084 lactam C3ONCZ00 O a cyclic amide (any ring size) R N R = H, alkyl, aryl

085 carboxylic acid hydrazide C3ONN100 4 O R R1 = H, alkyl, aryl R2 = H, alkyl, aryl 1 N 3 R N R R3 = H, alkyl, aryl 4 2 R = H, alkyl, aryl R 086 carboxylic acid azide C3ONN200 O R = H, alkyl, aryl + R N N N 087 hydroxamic acid C3ONOH00 O R = H, alkyl, aryl OH R N H 088 carboxylic acid amidine C3N2H000 R4 N R1 = H, alkyl, aryl 3 R2 = H, alkyl, aryl 1 R R N R3 = H, alkyl, aryl 4 2 R = H, alkyl, aryl R 089 carboxylic acid amidrazone C3NNN100 5 R 4 N R R1 = H, alkyl, aryl R2 = H, alkyl, aryl 1 N 3 R N R R3 = H, alkyl, aryl 4 2 R = H, alkyl, aryl R 5 R = H, alkyl, aryl 090 nitrile C3N00000 RCN R = H, alkyl, aryl 091 acyl halide C3OXX000 O R = H, alkyl, aryl X = F, Cl, Br, I R X 092 acyl fluoride C3OXF000 O R = H, alkyl, aryl R F 093 acyl chloride C3OXC000 O R = H, alkyl, aryl R Cl 094 acyl bromide C3OXB000 O R = H, alkyl, aryl R Br 095 acyl iodide C3OXI000 O R = H, alkyl, aryl R I 096 acyl cyanide C2OC3N00 O R = H, alkyl, aryl R C N 097 imido ester C3NOC000 R3 N 2 R1 = H, alkyl, aryl R 2 R1 O R = alkyl, aryl 3 R = H, alkyl, aryl 098 imidoyl halide C3NXX000 R2 N R1 = H, alkyl, aryl 1 2 R X R = H, alkyl, aryl X = F, Cl, Br, I 099 thiocarboxylic acid deriv. C3SO0000 S R = H, alkyl, aryl X = any hetero atom R X 100 thiocarboxylic acid C3SOH000 S R = H, alkyl, aryl X = OH, SH R X 101 thiocarboxylic acid ester C3SOC000 S 2 R1 = H, alkyl, aryl R 2 R1 X R = alkyl, aryl X = O, S 102 thiolactone C3SOCZ00 S a cyclic thioester (any ring size) X = O, S X

103 thiocarboxylic acid amide C3SNH000 S 2 R1 = H, alkyl, aryl 1 R 2 R N R = H, alkyl, aryl 3 3 R = H, alkyl, aryl R 104 thiolactam C3SNCZ00 S R N R = H, alkyl, aryl

105 imidothioester C3NSC000 R3 N 2 R1 = H, alkyl, aryl 1 R 2 R S R = alkyl, aryl 3 R = H, alkyl, aryl 106 oxohetarene C3ONAZ00 R any (hetero)aromatic compound with a C=O structure N O R = H, alkyl, aryl

107 thioxohetarene C3SNAZ00 R any (hetero)aromatic compound with a C=S structure N S R = H, alkyl, aryl

108 iminohetarene C3NNAZ00 R1 R2 N N R1 = H, alkyl, aryl R2 = H, alkyl, aryl

109 orthocarboxylic acid deriv. C3O30000 X X R = H, alkyl, aryl X = OH, alkoxy, aryloxy, R X (substituted) amino, etc. 110 carboxylic acid orthoester C3O3C000 R2O OR3 R1 = H, alkyl, aryl 1 4 R2, R3, R4 = alkyl, aryl R OR 111 carboxylic acid amide acetal C3O3NC00 R2O OR3 4 R1 = H, alkyl, aryl 1 R R N R2, R3 = alkyl, aryl 4 5 5 R , R = H, alkyl, aryl R 112 carboxylic acid anhydride C3O2C3O2 O O R1, R2 = H, alkyl, aryl 1 2 R O R 113 carboxylic acid imide C3ONC000 O O R1, R2 = H, alkyl, aryl 1 2 R N R R3 = H, alkyl, aryl, ... 3 R 114 carboxylic acid unsubst. imide C3ONCH10 O O R1, R2 = H, alkyl, aryl 1 2 R N R H 115 carboxylic acid subst. imide C3ONCC10 O O R1, R2 = H, alkyl, aryl 1 2 R N R R3 = anything but H R3 116 CO2 deriv. (general) C4000000 any carbon with 4 valences to hetero atoms 117 carbonic acid deriv. C4O30000 O output only if none of the more X, Y = any hetero atom specific types apply X Y 118 carbonic acid monoester C4O3C100 O R = alkyl, aryl HO OR 119 carbonic acid diester C4O3C200 O R1, R2 = alkyl, aryl 1 2 R O OR 120 carbonic acid ester halide C4O3CX00 O R = alkyl, aryl X = F, Cl, Br, I X OR 121 thiocarbonic acid deriv. C4SO0000 S X, Y = any hetero atom X Y 122 thiocarbonic acid monoester C4SOC100 S S may be in any other position R = alkyl, aryl (replacing O) HO OR 123 thiocarbonic acid diester C4SOC200 S S may be in any other position R1, R2 = alkyl, aryl (replacing O) 1 2 R O OR 124 thiocarbonic acid ester halide C4SOX_00 S R = alkyl, aryl X = F, Cl, Br, I X OR 125 carbamic acid deriv C4O2N000 O 1 R1, R2 = H, alkyl, aryl R N X X = OH, alkoxy, aryloxy, 2 halogen R 126 carbamic acid C4O2NH00 O 1 R1, R2 = H, alkyl, aryl R N OH 2 R 127 carbamic acid ester C4O2NC00 O (urethane) 1 R1, R2 = H, alkyl, aryl R 3 3 N OR R = alkyl, aryl 2 R 128 carbamic acid halide C4O2NX00 O 1 R1, R2 = H, alkyl, aryl R N X X = F, Cl, Br, I 2 R 129 thiocarbamic acid deriv. C4SN0000 S 1 R1, R2 = H, alkyl, aryl R N X X = OH, alkoxy, aryloxy, 2 halogen R 130 thiocarbamic acid C4SNOH00 S also possible: SH instead of OH 1 R1, R2 = H, alkyl, aryl R N OH 2 R 131 thiocarbamic acid ester C4SNOC00 S 1 R1, R2 = H, alkyl, aryl R 3 3 N OR R = alkyl, aryl 2 R 132 thiocarbamic acid halide C4SNXX00 S 1 R1, R2 = H, alkyl, aryl R N X X = F, Cl, Br, I 2 R 133 urea C4O1N200 O R1 R4 N N 3 R2 R R1, R2, R3, R4 = H, alkyl, aryl

134 isourea C4N2O100 R4 O R1 N N R2 R3 R1, R2, R3, R4 = H, alkyl, aryl

135 thiourea C4S1N200 S R1 R4 N N 2 3 1 2 3 4 R R R , R , R , R = H, alkyl, aryl

136 isothiourea C4N2S100 R4 S R1 N N R2 R3 R1, R2, R3, R4 = H, alkyl, aryl

137 guanidine C4N30000 R5 N R1 R4 N N R2 R3 R1, R2, R3, R4, R5 = H, alkyl, aryl

5 138 semicarbazide C4ON2N00 O R 1 R N 4 N N R R2 R3 R1, R2, R3, R4, R5 = H, alkyl, aryl

5 139 thiosemicarbazide C4SN2N00 S R 1 R N 4 N N R R2 R3 R1, R2, R3, R4, R5 = H, alkyl, aryl

140 azide N4N20000 + R NNN R = alkyl, aryl

1 141 azo compound N2N10000 R N 2 R1, R2 = alkyl, aryl N R + 142 diazonium salt N3N100T2 R NN R = alkyl, aryl

143 isonitrile N3C10000 + R N C R = alkyl, aryl

144 cyanate C4NO1000 RO CN R = alkyl, aryl

145 isocyanate C4NO2000 R NCO R = alkyl, aryl

146 thiocyanate C4NS1000 RS CN R = alkyl, aryl

147 isothiocyanate C4NS2000 R NCS R = alkyl, aryl

1 2 148 carbodiimide C4N20000 R NCN R R1, R2 = H, alkyl, aryl

149 nitroso compound N2O10000 R NO R = alkyl, aryl

150 nitro compound N4O20000 O R N R = alkyl, aryl O 151 nitrite N3O20000 RO NO R = alkyl, aryl

152 nitrate N4O30000 O RO N R = alkyl, aryl O 153 sulfuric acid deriv. S6O00000 O for query purposes only X, Y = any hetero atom X S Y

O 154 sulfuric acid S6O4H000 O HO S OH

O 155 sulfuric acid monoester S6O4HC00 O R = alkyl, aryl RO S OH

O 156 sulfuric acid diester S6O4CC00 O 1 2 1 2 R , R = alkyl, aryl R O S OR

O 157 sulfuric acid amide ester S6O3NC00 O 3 R 1 1 R = alkyl, aryl R O S N R2, R3 = H, alkyl, aryl R2 O 158 sulfuric acid amide S6O3N100 O R2 R1, R2 = H, alkyl, aryl HO S N R1 O 159 sulfuric acid diamide S6O2N200 R1 O R4 R1, R2, R3, R4 = H, alkyl, aryl N S N R2 R3 O 160 sulfuryl halide S6O3XX00 O X = F, Cl, Br, I X S Y Y = any hetero atom O 161 sulfonic acid deriv. S5O00000 O for query purposes only R = alkyl, aryl R S X X = any hetero atom O 162 sulfonic acid S5O3H000 O R = alkyl, aryl R S OH

O 163 sulfonic acid ester S5O3C000 O 1 2 1 2 R , R = alkyl, aryl R S OR

O 164 sulfonamide S5O2N000 O 3 R 1 1 R = alkyl, aryl R S N R2, R3 = H, alkyl, aryl R2 O 165 sulfonyl halide S5O2XX00 O R = alkyl, aryl R S X X = F, Cl, Br, I O 166 sulfone S4O20000 O 1 2 1 2 R , R = alkyl, aryl R S R

O 167 sulfoxide S2O10000 O R1, R2 = alkyl, aryl 1 S 2 R R 168 sulfinic acid deriv. S3O00000 O for query purposes only R = alkyl, aryl S X = any hetero atom R X 169 sulfinic acid S3O2H000 O R = alkyl, aryl S R OH 170 sulfinic acid ester S3O2C000 O R1, R2 = alkyl, aryl 1 S 2 R OR 171 sulfinic acid halide S3O1XX00 O R = alkyl, aryl S X = F, Cl, Br, I R X 172 sulfinic acid amide S3O1N000 O R3 R1 = alkyl, aryl R1 S N R2, R3 = H, alkyl, aryl 2 R 173 sulfenic acid deriv. S1O00000 R = alkyl, aryl for query purposes only R S X X = any hetero atom 174 sulfenic acid S1O1H000 R = alkyl, aryl R S OH

175 sulfenic acid ester S1O1C000 1 2 R1, R2 = alkyl, aryl R S OR

176 sulfenic acid halide S1O0XX00 R = alkyl, aryl R S X X = F, Cl, Br, I 177 sulfenic acid amide S1O0N100 R3 1 S R1 = alkyl, aryl R N R2, R3 = H, alkyl, aryl R2

178 thiol S1H10000 RSH R = alkyl, aryl 179 alkylthiol S1H1C000 RSH R = alkyl 180 arylthiol S1H1A000 RSH R = aryl 181 phosphoric acid deriv. P5O0H000 O for query purposes only X, Y, Z = O, N, Hal residue P X Z Y 182 phosphoric acid P5O4H200 O P HO OH HO 183 phosphoric acid ester P5O4HC00 O R = alkyl, aryl P X OR X, Y = any O, N, Hal residue Y 184 phosphoric acid halide P5O3HX00 O X = F, Cl, Br, I P X Z Y, Z = any O, N, Hal residue Y 185 phosphoric acid amide P5O3HN00 O 1 P R X N R1, R2 = H, alkyl, aryl Y 2 R X, Y = any O, N, Hal residue 186 thiophosphoric acid deriv. P5O0S000 S for query purposes only X, Y, Z = any O, N, Hal residue P X Z Y 187 thiophosphoric acid P5O3SH00 S P HO OH HO 188 thiophosphoric acid ester P5O3SC00 S R = alkyl, aryl P X OR X, Y = any O, N, Hal residue Y 189 thiophosphoric acid halide P5O2SX00 S X = F, Cl, Br, I P X Z Y, Z = any O, N, Hal residue Y 190 thiophosphoric acid amide P5O2SN00 S 1 P R X N R1, R2 = H, alkyl, aryl Y 2 R X, Y = any O, N, Hal residue 191 phosphonic acid deriv. P4O30000 O R = alkyl, aryl P R Y X, Y = any O, N, Hal residue X 192 phosphonic acid P4O3H000 O R = alkyl, aryl P R OH OH 193 phosphonic acid ester P4O3C000 O R1, R2 = alkyl, aryl 1 P 2 R OR X = any O, N, Hal residue X 194 phosphine P3000000 R3 R1, R2, R3 = alkyl, aryl 1 P 2 R R 195 phosphinoxide P2O00000 O R1, R2, R3 = alkyl, aryl P R1 R3 2 R 196 boronic acid deriv. B2O20000 X R = alkyl, aryl B X, Y = any O, N, Hal residue R Y 197 boronic acid B2O2H000 OH R = alkyl, aryl B R OH 198 boronic acid ester B2O2C000 X R1, R2 = alkyl, aryl 1 B 2 X = any O, N, Hal residue R OR 199 alkene 000C2C00 R4 R1 R3 R1, R2, R3, R4 = H, alkyl, aryl 2 R 200 alkyne 000C3C00 1 2 1 2 R R R , R = H, alkyl, aryl 201 aromatic compound 0000A000 any aromatic carbocyclic or heterocyclic structure, criteria: conjugated system, including cyclopentadienyl anion, tropylium cation, Hückel’s rule must apply (4n + 2 pi fulvene, tropone, pyridone-type lactams, etc. electrons); planar geometry is not checked 202 heterocyclic compound 0000CZ00 any cyclic structure with at least one non-carbon starting with v0.3b, metal atoms are atom incorporated not accepted as ring members, unless option –M is used 203 alpha-aminoacid C3O2HN1C O 1 R1, R2 = H, alkyl, aryl R OH

2 NH R 204 alpha-hydroxyacid C3O2HO1H O R = H, alkyl, aryl R OH

OH