341-88-8

Basic information

• Product Name: 2-HEPTYL-4-HYDROXYQUINOLINE N-OXIDE
• Synonyms: 2-(n-heptyl)-4-hydroxyquinolinen-oxide;2-heptyl-4-quinolino1-oxide;hqno;kf8940;2-Heptylquinolin-4-ol 1-oxide;Antibiotic KF-8940;Pyo II;C04284
• CAS NO: 341-88-8
• Molecular Formula: C16H19NO2
• Molecular Weight: 257.32756
• Mol File: 341-88-8.mol
• Article Data: 1

Chemical Properties

• Melting Point: 156-157°
• Boiling Point: 385.8°Cat760mmHg
• Flash Point: 187.1°C
• Appearance: /
• Density: 1.116g/cm³
• Vapor Pressure: 0mmHg at 25°C
• Refractive Index: 1.558
• Storage Temp.: −20°C
• Solubility: Soluble in DMSO (up to 8 mg/ml with warming), or in Ethanol (up to 13 mg/ml with warming).
• PKA: 1.07±0.40(Predicted)
• Stability: Stable for 2 years from date of purchase as supplied. Solutions in DMSO or ethanol may be stored at -20° for up to 1 month.
• CAS DataBase Reference: 2-HEPTYL-4-HYDROXYQUINOLINE N-OXIDE(CAS DataBase Reference)
• NIST Chemistry Reference: 2-HEPTYL-4-HYDROXYQUINOLINE N-OXIDE(341-88-8)
• EPA Substance Registry System: 2-HEPTYL-4-HYDROXYQUINOLINE N-OXIDE(341-88-8)

Safety Data

• RTECS: VC5890000
• Hazardous Substances Data: 341-88-8(Hazardous Substances Data)

Usage

Description

HQNO (341-88-8) is a naturally occurring antagonist of dihydrostreptomycin. Potent inhibitor of the respiratory chain binding to the mitochondrial cytochrome b protein. HQNO inhibits NADH oxidase (NADH) and Na+-dependent NADH-quinone reductase (NQR).

Uses

HQNO is a streptomycin antagonist. A naturally occurring antagonist of dihydrostreptomycin.

References

References/Citations 1) Nakayama?et al. (1999),?Inhibitor studies of a new antibiotic, korormicin, 2-n-heptyl-4-hydroxyquinoline N-oxide and Ag+?toward the Na+-translocating NADH-quinone reductase from the marine Vibrio alginolyticus; Biol. Pharm. Bull.,?221064

InChI:InChI=1/C16H21NO2/c1-2-3-4-5-6-9-13-12-16(18)14-10-7-8-11-15(14)17(13)19/h7-8,10-12,18H,2-6,9H2,1H3

Upstream product

• 16662-90-1 3-(2-aminophenyl)-3-oxopropanoic acid 
• 1264-52-4 octanoyl coenzyme A 

Downstream Products

• 2503-80-2 4-hydroxy-2-heptylquinoline 

Relevant articles and documents

PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa

Alkyl hydroxyquinoline N-oxides (AQNOs) are antibiotic compounds produced by the opportunistic bacterial pathogen Pseudomonas aeruginosa. They are products of the alkyl quinolone (AQ) biosynthetic pathway, which also generates the quorum-sensing molecules 2-heptyl-4(1H)-quinolone (HHQ) and 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS). Although the enzymatic synthesis of HHQ and PQS had been elucidated, the route by which AQNOs are synthesized remained elusive. Here, we report on PqsL, the key enzyme for AQNO production, which structurally resembles class A flavoprotein monooxygenases such as p-hydroxybenzoate 3-hydroxylase (pHBH) and 3-hydroxybenzoate 6-hydroxylase. However, we found that unlike related enzymes, PqsL hydroxylates a primary aromatic amine group, and it does not use NAD(P)H as cosubstrate, but unexpectedly required reduced flavin as electron donor. We also observed that PqsL is active toward 2-aminobenzoylacetate (2-ABA), the central intermediate of the AQ pathway, and forms the unstable compound 2-hydroxylaminobenzoylacetate, which was preferred over 2-ABA as substrate of the downstream enzyme PqsBC. In vitro reconstitution of the PqsL/PqsBC reaction was feasible by using the FAD reductase HpaC, and we noted that the AQ:AQNO ratio is increased in an hpaC-deletion mutant of P. aeruginosa PAO1 compared with the ratio in the WT strain. A structural comparison with pHBH, the model enzyme of class A flavoprotein monooxygenases, revealed that structural features associated with NAD(P)H binding are missing in PqsL. Our study completes the AQNO biosynthetic pathway in P. aeruginosa, indicating that PqsL produces the unstable product 2-hydroxylaminobenzoylacetate from 2-ABA and depends on free reduced flavin as electron donor instead of NAD(P)H.