Exact Mass: 238.058969
Exact Mass Matches: 238.058969
Found 209 metabolites which its exact mass value is equals to given mass value 238.058969,
within given mass tolerance error 0.01 dalton. Try search metabolite list with more accurate mass tolerance error
0.001 dalton.
3-Hydroxyflavone
Flavonol is a monohydroxyflavone that is the 3-hydroxy derivative of flavone. It is a monohydroxyflavone and a member of flavonols. It is a conjugate acid of a flavonol(1-). 3-Hydroxyflavone is a natural product found in Acacia retinodes, Acacia holosericea, and other organisms with data available. Constituent of cabbage. 3-Hydroxyflavone is found in many foods, some of which are red raspberry, brassicas, papaya, and pomegranate. 3-Hydroxyflavone is found in brassicas. 3-Hydroxyflavone is a constituent of cabbage Flavonol is an endogenous metabolite. Flavonol is an endogenous metabolite.
Primuliten
5-Hydroxyflavone is a member of flavones. 5-Hydroxyflavone is a natural product found in Conchocarpus heterophyllus, Primula denticulata, and Lophomyrtus bullata with data available. relative retention time with respect to 9-anthracene Carboxylic Acid is 1.263 relative retention time with respect to 9-anthracene Carboxylic Acid is 1.268 5-Hydroxyflavone, a flavonoid ligand, shows no cytotoxic activity against MCF-7, FaDU, MDA-MB-435S, U87, RPE-1, and HEK293 cells[1]. 5-Hydroxyflavone, a flavonoid ligand, shows no cytotoxic activity against MCF-7, FaDU, MDA-MB-435S, U87, RPE-1, and HEK293 cells[1].
7-Hydroxyflavone
[Raw Data] CB049_7-Hydroxyflavone_pos_10eV_CB000023.txt [Raw Data] CB049_7-Hydroxyflavone_pos_30eV_CB000023.txt [Raw Data] CB049_7-Hydroxyflavone_pos_50eV_CB000023.txt [Raw Data] CB049_7-Hydroxyflavone_pos_20eV_CB000023.txt [Raw Data] CB049_7-Hydroxyflavone_pos_40eV_CB000023.txt [Raw Data] CB049_7-Hydroxyflavone_neg_20eV_000015.txt [Raw Data] CB049_7-Hydroxyflavone_neg_10eV_000015.txt [Raw Data] CB049_7-Hydroxyflavone_neg_40eV_000015.txt [Raw Data] CB049_7-Hydroxyflavone_neg_30eV_000015.txt [Raw Data] CB049_7-Hydroxyflavone_neg_50eV_000015.txt 7-Hydroxyflavone is a flavonoid isolated from Clerodendrum phlomidis, with anti-inflammatory activity. 7-Hydroxyflavone protects renal cells from nicotine (NIC)-associated cytotoxicity via the ERK/Nrf2/HO-1 pathway[1][2]. 7-Hydroxyflavone is a flavonoid isolated from Clerodendrum phlomidis, with anti-inflammatory activity. 7-Hydroxyflavone protects renal cells from nicotine (NIC)-associated cytotoxicity via the ERK/Nrf2/HO-1 pathway[1][2]. 7-Hydroxyflavone is a flavonoid isolated from Clerodendrum phlomidis, with anti-inflammatory activity. 7-Hydroxyflavone protects renal cells from nicotine (NIC)-associated cytotoxicity via the ERK/Nrf2/HO-1 pathway[1][2].
6-Hydroxyflavone
6-Hydroxyflavone is a naturally occurring flavone, with anti-inflammatory activity. 6-Hydroxyflavone exhibits inhibitory effect towards bovine hemoglobin (BHb) glycation. 6-Hydroxyflavone can activate AKT, ERK 1/2, and JNK signaling pathways to effectively promote osteoblastic differentiation. 6-Hydroxyflavone inhibits the LPS-induced NO production[1] [2]. 6-Hydroxyflavone is a naturally occurring flavone, with anti-inflammatory activity. 6-Hydroxyflavone exhibits inhibitory effect towards bovine hemoglobin (BHb) glycation. 6-Hydroxyflavone can activate AKT, ERK 1/2, and JNK signaling pathways to effectively promote osteoblastic differentiation. 6-Hydroxyflavone inhibits the LPS-induced NO production[1] [2].
3-deoxy-D-manno-octulosonate
3-deoxy-d-manno-octulosonate, also known as kdo or 2-dehydro-3-deoxy-D-octonate, belongs to sugar acids and derivatives class of compounds. Those are compounds containing a saccharide unit which bears a carboxylic acid group. 3-deoxy-d-manno-octulosonate is soluble (in water) and a moderately acidic compound (based on its pKa). 3-deoxy-d-manno-octulosonate can be found in a number of food items such as peppermint, okra, horseradish tree, and hazelnut, which makes 3-deoxy-d-manno-octulosonate a potential biomarker for the consumption of these food products. 3-deoxy-d-manno-octulosonate may be a unique E.coli metabolite.
2-Hydroxymethylanthraquinone
2-hydroxymethylanthraquinone, also known as anthraquinone-2-methanol or hmaq-one, is a member of the class of compounds known as anthraquinones. Anthraquinones are organic compounds containing either anthracene-9,10-quinone, 1,4-anthraquinone, or 1,2-anthraquinone. 2-hydroxymethylanthraquinone is practically insoluble (in water) and a very weakly acidic compound (based on its pKa). 2-hydroxymethylanthraquinone can be found in turmeric, which makes 2-hydroxymethylanthraquinone a potential biomarker for the consumption of this food product. 2-(Hydroxymethyl)anthraquinone is used as a photoremovable protecting group (PRPG) to chemically cage sex pheromone (e.g. (Z)-11-hexadecen-1-ol (sex pheromone of?Chilo infuscatellussnellen))[1]. 2-(Hydroxymethyl)anthraquinone is used as a photoremovable protecting group (PRPG) to chemically cage sex pheromone (e.g. (Z)-11-hexadecen-1-ol (sex pheromone of?Chilo infuscatellussnellen))[1].
7-Chlorotryptophan
A tryptophan derivative having a chloro substituent at the 7-position. A D-tryptophan derivative having a chloro substituent at the 7-position. An L-tryptophan derivative having a chloro substituent at the 7-position.
Rufinamide
C10H8F2N4O (238.06661419999998)
D002317 - Cardiovascular Agents > D026941 - Sodium Channel Blockers > D061567 - Voltage-Gated Sodium Channel Blockers N - Nervous system > N03 - Antiepileptics > N03A - Antiepileptics > N03AF - Carboxamide derivatives C78272 - Agent Affecting Nervous System > C264 - Anticonvulsant Agent D002491 - Central Nervous System Agents > D000927 - Anticonvulsants D049990 - Membrane Transport Modulators CONFIDENCE standard compound; EAWAG_UCHEM_ID 3143
6-Chloro-L-tryptophan
A non-proteinogenic L-alpha-amino acid that is L-tryptophan in which the hydrogen at position 6 on the indole ring has been replaced by a chlorine. Sweetening agent, sweetness 1300x sucrose
5-Chlorotryptophan
A non-proteinogenic L-alpha-amino acid that is L-tryptophan in which the hydrogen at position 5 of the indole ring has been replaced by a chlorine.
5-Hydroxyflavone
5-Hydroxyflavone, a flavonoid ligand, shows no cytotoxic activity against MCF-7, FaDU, MDA-MB-435S, U87, RPE-1, and HEK293 cells[1]. 5-Hydroxyflavone, a flavonoid ligand, shows no cytotoxic activity against MCF-7, FaDU, MDA-MB-435S, U87, RPE-1, and HEK293 cells[1].
1-(1-Propenylsulfinyl)propyl propyl disulfide
1-(1-Propenylsulfinyl)propyl propyl disulfide is found in onion-family vegetables. 1-(1-Propenylsulfinyl)propyl propyl disulfide is a constituent of Allium cepa (onion) and Allium tricoccum (wood leek). Constituent of Allium cepa (onion) and Allium tricoccum (wood leek). 1-(1-Propenylsulfinyl)propyl propyl disulfide is found in garden onion and onion-family vegetables.
L-4-Chlorotryptophan
L-4-Chlorotryptophan is found in common pea. L-4-Chlorotryptophan is isolated from the seed protein of Pisum sativum (pea). Also obtained from the seeds of Vicia fab Isolated from the seed protein of Pisum sativum (pea)and is also obtained from the seeds of Vicia faba. 4-Chloro-L-tryptophan is found in pulses and common pea.
Cystathionine sulfoxide
One of the unusual cystathionine metabolites found in the urine of patients with cystathioninuria [HMDB] One of the unusual cystathionine metabolites found in the urine of patients with cystathioninuria.
1-Propenyl 1-(propylsulfinyl)propyl disulfide
1-Propenyl 1-(propylsulfinyl)propyl disulfide is found in onion-family vegetables. 1-Propenyl 1-(propylsulfinyl)propyl disulfide is a constituent of Allium tricoccum (wood leek). Constituent of Allium tricoccum (wood leek). 1-Propenyl 1-(propylsulfinyl)propyl disulfide is found in onion-family vegetables.
(±)-6-Chlorotryptophan
Sweetening agent, sweetness 1300x sucrose.
1-(2-Propenylsulfinyl)propyl propyl disulfide
1-(2-Propenylsulfinyl)propyl propyl disulfide is found in onion-family vegetables. 1-(2-Propenylsulfinyl)propyl propyl disulfide is a constituent of Allium sp Constituent of Allium species 1-(2-Propenylsulfinyl)propyl propyl disulfide is found in onion-family vegetables.
2-Propenyl 1-(propylsulfinyl)propyl disulfide
2-Propenyl 1-(propylsulfinyl)propyl disulfide is found in onion-family vegetables. 2-Propenyl 1-(propylsulfinyl)propyl disulfide is a constituent of Allium sp Constituent of Allium species 2-Propenyl 1-(propylsulfinyl)propyl disulfide is found in onion-family vegetables.
Picartamide
C78276 - Agent Affecting Digestive System or Metabolism > C29701 - Anti-ulcer Agent > C29723 - Proton Pump Inhibitor
Rufinamide
C10H8F2N4O (238.06661419999998)
D002317 - Cardiovascular Agents > D026941 - Sodium Channel Blockers > D061567 - Voltage-Gated Sodium Channel Blockers N - Nervous system > N03 - Antiepileptics > N03A - Antiepileptics > N03AF - Carboxamide derivatives C78272 - Agent Affecting Nervous System > C264 - Anticonvulsant Agent D002491 - Central Nervous System Agents > D000927 - Anticonvulsants D049990 - Membrane Transport Modulators
Primuletin
5-Hydroxyflavone, a flavonoid ligand, shows no cytotoxic activity against MCF-7, FaDU, MDA-MB-435S, U87, RPE-1, and HEK293 cells[1]. 5-Hydroxyflavone, a flavonoid ligand, shows no cytotoxic activity against MCF-7, FaDU, MDA-MB-435S, U87, RPE-1, and HEK293 cells[1].
1,3-bis(4-hydroxyphenyl)prop-2-yn-1-one|anemarchalconyn
CZODYZFOLUNSFR-UHFFFAOYSA-N
1-hydroxy-2-methyl-9,10-anthraquinone is a member of the class of hydroxyanthraquinones that is anthracene-9,10-dione substituted by a hydroxy group at position 1 and a methyl group at position 2. It has been isolated from the roots of Rubia yunnanensis. It has a role as a plant metabolite. 1-Hydroxy-2-methylanthraquinone is a natural product found in Prismatomeris tetrandra, Galium spurium, and other organisms with data available. A member of the class of hydroxyanthraquinones that is anthracene-9,10-dione substituted by a hydroxy group at position 1 and a methyl group at position 2. It has been isolated from the roots of Rubia yunnanensis.
ACon1_000093
7-hydroxyflavone is a hydroxyflavonoid in which the flavone nucleus is substituted at position 7 by a hydroxy group. 7-Hydroxyflavone is a natural product found in Lawsonia inermis, Berberis dictyota, and other organisms with data available. 7-Hydroxyflavone is a flavonoid isolated from Clerodendrum phlomidis, with anti-inflammatory activity. 7-Hydroxyflavone protects renal cells from nicotine (NIC)-associated cytotoxicity via the ERK/Nrf2/HO-1 pathway[1][2]. 7-Hydroxyflavone is a flavonoid isolated from Clerodendrum phlomidis, with anti-inflammatory activity. 7-Hydroxyflavone protects renal cells from nicotine (NIC)-associated cytotoxicity via the ERK/Nrf2/HO-1 pathway[1][2]. 7-Hydroxyflavone is a flavonoid isolated from Clerodendrum phlomidis, with anti-inflammatory activity. 7-Hydroxyflavone protects renal cells from nicotine (NIC)-associated cytotoxicity via the ERK/Nrf2/HO-1 pathway[1][2].
6-Hydroxyflavone
6-Hydroxyflavone is a hydroxyflavonoid. 6-Hydroxyflavone is a natural product found in Scutellaria baicalensis with data available. 6-Hydroxyflavone is a naturally occurring flavone, with anti-inflammatory activity. 6-Hydroxyflavone exhibits inhibitory effect towards bovine hemoglobin (BHb) glycation. 6-Hydroxyflavone can activate AKT, ERK 1/2, and JNK signaling pathways to effectively promote osteoblastic differentiation. 6-Hydroxyflavone inhibits the LPS-induced NO production[1] [2]. 6-Hydroxyflavone is a naturally occurring flavone, with anti-inflammatory activity. 6-Hydroxyflavone exhibits inhibitory effect towards bovine hemoglobin (BHb) glycation. 6-Hydroxyflavone can activate AKT, ERK 1/2, and JNK signaling pathways to effectively promote osteoblastic differentiation. 6-Hydroxyflavone inhibits the LPS-induced NO production[1] [2].
HMAQ-one
2-(hydroxymethyl)anthraquinone is an anthraquinone. It has a role as a metabolite. 2-(Hydroxymethyl)anthraquinone is a natural product found in Rubia yunnanensis and Handroanthus impetiginosus with data available. 2-(Hydroxymethyl)anthraquinone is used as a photoremovable protecting group (PRPG) to chemically cage sex pheromone (e.g. (Z)-11-hexadecen-1-ol (sex pheromone of?Chilo infuscatellussnellen))[1]. 2-(Hydroxymethyl)anthraquinone is used as a photoremovable protecting group (PRPG) to chemically cage sex pheromone (e.g. (Z)-11-hexadecen-1-ol (sex pheromone of?Chilo infuscatellussnellen))[1].
7-Hydroxyflavone
7-Hydroxyflavone is a flavonoid isolated from Clerodendrum phlomidis, with anti-inflammatory activity. 7-Hydroxyflavone protects renal cells from nicotine (NIC)-associated cytotoxicity via the ERK/Nrf2/HO-1 pathway[1][2]. 7-Hydroxyflavone is a flavonoid isolated from Clerodendrum phlomidis, with anti-inflammatory activity. 7-Hydroxyflavone protects renal cells from nicotine (NIC)-associated cytotoxicity via the ERK/Nrf2/HO-1 pathway[1][2]. 7-Hydroxyflavone is a flavonoid isolated from Clerodendrum phlomidis, with anti-inflammatory activity. 7-Hydroxyflavone protects renal cells from nicotine (NIC)-associated cytotoxicity via the ERK/Nrf2/HO-1 pathway[1][2].
3-Hydroxyflavone
Flavonol is an endogenous metabolite. Flavonol is an endogenous metabolite.
5-Hydroxyflavone
5-Hydroxyflavone, a flavonoid ligand, shows no cytotoxic activity against MCF-7, FaDU, MDA-MB-435S, U87, RPE-1, and HEK293 cells[1]. 5-Hydroxyflavone, a flavonoid ligand, shows no cytotoxic activity against MCF-7, FaDU, MDA-MB-435S, U87, RPE-1, and HEK293 cells[1].
7-hydroxy-2-phenylchromen-4-one [IIN-based: Match]
7-hydroxy-2-phenylchromen-4-one [IIN-based on: CCMSLIB00000849074]
1-Propenyl 1-(propylsulfinyl)propyl disulfide
1-(1-Propenylsulfinyl)propyl propyl disulfide
2-Propenyl 1-(propylsulfinyl)propyl disulfide
Uranium
U (238.050786)
Uranium, also known as 92u or uran, is a member of the class of compounds known as homogeneous actinide compounds. Homogeneous actinide compounds are inorganic compounds containing only metal atoms,with the largest atom being a transition metal atom. Uranium can be found in a number of food items such as common hazelnut, soft-necked garlic, sunburst squash (pattypan squash), and red beetroot, which makes uranium a potential biomarker for the consumption of these food products. Uranium is formally rated as a carcinogenic (IARC 1) potentially toxic compound. Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 is the only naturally occurring fissile isotope, which makes it widely used in nuclear power plants and nuclear weapons. However, because of the tiny amounts found in nature, uranium needs to undergo enrichment so that enough uranium-235 is present. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology. Uranium-238 has a small probability for spontaneous fission or even induced fission with fast neutrons; uranium-235 and to a lesser degree uranium-233 have a much higher fission cross-section for slow neutrons. In sufficient concentration, these isotopes maintain a sustained nuclear chain reaction. This generates the heat in nuclear power reactors, and produces the fissile material for nuclear weapons. Depleted uranium (238U) is used in kinetic energy penetrators and armor plating. Uranium is used as a colorant in uranium glass, producing lemon yellow to green colors. Uranium glass fluoresces green in ultraviolet light. It was also used for tinting and shading in early photography .
ethyl(5-isocyanato-2-methylphenyl)carbamoyl chloride
8-CHLORO-2-METHYL-IMIDAZO[1,2-A]PYRIDINE-3-CARBOXYLIC ACID ETHYL ESTER
6-Chloro-9-(tetrahydro-2-pyranyl)purine
C10H11ClN4O (238.06213459999998)
(2-CHLORO-BENZOIMIDAZOL-1-YL)-ACETIC ACID ETHYL ESTER
[3,5-Bis(methoxycarbonyl)phenyl]boronic acid
C10H11BO6 (238.06486560000002)
9H-Fluorene-4-carboxylicacid, 9-oxo-, methyl ester
Silanediol,1-methyl-1-phenyl-, 1,1-diacetate
C11H14O4Si (238.06613240000001)
3-(2-Chloroethyl)-9-hydroxy-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one
1H-Pyrazolo[3,4-d]pyrimidine,4-chloro-1-(tetrahydro-2H-pyran-2-yl)-
C10H11ClN4O (238.06213459999998)
5-(chloromethyl)-3-[(4-methylphenoxy)methyl]-1,2,4-oxadiazole
sinitrodil
C78274 - Agent Affecting Cardiovascular System > C270 - Antihypertensive Agent
2,8-DIAZA-SPIRO[4.5]DECANE-2-CARBOXYLIC ACID TERT-BUTYL ESTER
C7H9F3N4S (238.04999899999999)
2-(chloromethyl)-5-(4-ethoxyphenyl)-1,3,4-oxadiazole
Ethyl 6-chloro-5-methyl-1H-pyrrolo[2,3-b]pyridine-2-carboxylate
1H-Pyrrolo[2,3-b]pyridine-3-acetic acid, 6-chloro-2-Methyl-, Methyl ester
Ethyl 4-chloro-2-methyl-1H-pyrrolo[2,3-b]pyridine-5-carboxylate
4-Chloro-5-(1,3-dioxolan-2-yl)-2-methyl-1H-pyrrolo[2,3-b]pyridine
ethyl 6-chloro-2-methylimidazo[1,2-a]pyridine-3-carboxylate
1-FURAN-2-YLMETHYL-PYRROLIDIN-3-YLAMINE DIHYDROCHLORIDE
6-(TERT-BUTYL)-4-CHLORO-1H-PYRROLO[3,4-C]PYRIDINE-1,3(2H)-DIONE
4-chloro-1-(methoxymethyl)-2-methylpyrrolo[2,3-b]pyridine-5-carbaldehyde
4-(4-METHYL-5-(METHYLSULFONYL)-4H-1,2,4-TRIAZOL-3-YL)PYRIDINE
3-(4-METHYL-5-(METHYLSULFONYL)-4H-1,2,4-TRIAZOL-3-YL)PYRIDINE
ethyl 6-chloro-5-cyano-2-ethylpyridine-3-carboxylate
(2,4-BIS(METHOXYCARBONYL)PHENYL)BORONIC ACID
C10H11BO6 (238.06486560000002)
Simethicone
D013501 - Surface-Active Agents > D000934 - Antifoaming Agents D003879 - Dermatologic Agents > D004643 - Emollients D001697 - Biomedical and Dental Materials
ETHYL 2-(5-CHLORO-1H-BENZO[D]IMIDAZOL-2-YL)ACETATE
6-chloro-4-propan-2-yloxypyrido[3,2-d]pyrimidin-2-amine
C10H11ClN4O (238.06213459999998)
TRANS-2-(2-THIOPHENECARBONYL)-1-CYCLOHEXANECARBOXYLIC ACID
1-[(4-CHLORO-3-ETHYL-1-METHYL-1H-PYRAZOL-5-YL)CARBONYL]-1H-IMIDAZOLE
C10H11ClN4O (238.06213459999998)
ethyl 3-chloro-8-methylimidazo[1,2-a]pyridine-2-carboxylate
4-(1H-IMIDAZOL-1-YLMETHYL)BENZOIC ACID HYDROCHLORIDE
4-(4-chloro-7H-pyrrolo[2,3-d]pyrimidin-2-yl)morpholine
C10H11ClN4O (238.06213459999998)
3-(3,4-Dichlorophenyl)-1,1-bis[(2H3)methyl]urea
C9H4Cl2D6N2O (238.05467806800002)
(3,4-Bis(methoxycarbonyl)phenyl)boronic acid
C10H11BO6 (238.06486560000002)
2-Chloro-1-[1-(3-isoxazolyl)-2,5-dimethyl-3-pyrrolyl]ethanone
5-fluoro-N-(2-sulfanylethyl)-1H-indole-2-carboxamide
(4S)-4-{[(2S)-2-Amino-3-oxopropyl]sulfanyl}-L-homoserine
CHEBI:28649
2-(Hydroxymethyl)anthraquinone is used as a photoremovable protecting group (PRPG) to chemically cage sex pheromone (e.g. (Z)-11-hexadecen-1-ol (sex pheromone of?Chilo infuscatellussnellen))[1]. 2-(Hydroxymethyl)anthraquinone is used as a photoremovable protecting group (PRPG) to chemically cage sex pheromone (e.g. (Z)-11-hexadecen-1-ol (sex pheromone of?Chilo infuscatellussnellen))[1].
flavonol
Flavonol is an endogenous metabolite. Flavonol is an endogenous metabolite.
(2S)-2-azaniumyl-3-(6-chloro-1H-indol-3-yl)propanoate
(2S)-2-azaniumyl-3-(7-chloro-1H-indol-3-yl)propanoate
(2S)-2-ammonio-3-(5-chloro-1H-indol-3-yl)propanoate
(2R)-2-ammonio-3-(6-chloro-1H-indol-3-yl)propanoate
(2S,3R)-2-[(2-aminophenyl)amino]-3-carboxy-3-hydroxypropanoate
5-(2-Fluorophenoxy)-1-methyl-3-nitro-1,2,4-triazole
C9H7FN4O3 (238.05021639999998)
Ethyl 4-chloro-2-(methylsulfanyl)hexahydropyrimidine-5-carboxylate
5-[(2,4,5-Trihydroxyphenyl)methyl]imidazolidine-2,4-dione
3,4,5-Trihydroxy-6-(2-hydroxyethoxy)oxane-2-carboxylic acid
7-chloro-L-tryptophan zwitterion
Zwitterionic form of 7-chloro-L-tryptophan.
5-chloro-L-tryptophan zwitterion
An L-alpha-amino acid zwitterion resulting from the transfer of a proton from the carboxy group to the alpha-amino group of 5-chloro-L-tryptophan.
6-(1,2-dihydroxyethyl)-2,4,5-trihydroxyoxane-2-carboxylic acid
7-Hydroxyisoflavone
The simplest member of the class of 7-hydroxyisoflavones that is isoflavone with a hydroxy substituent at position 7.
N-acetyl-S-phenyl-L-cysteine(1-)
An S-substituted N-acetyl-L-cysteinate that is the conjugate base of N-acetyl-S-phenyl-L-cysteine resulting from the deprotonation of the carboxy group; major species at pH 7.3.
6-chloro-L-tryptophan zwitterion
An L-alpha-amino acid zwitterion resulting from the transfer of a proton from the carboxy group to the alpha-amino group of 6-chloro-L-tryptophan; major species at pH 7.3.