6-APB

6-(2-aminopropyl)benzofuran or 1-benzofuran-6-ylpropan-2-amine (6-APB), also known as Benzofury, is an entactogenic compound of the phenethylamine and amphetamine classes. It is a recreational drug that is similar in structure to MDA, but differs in that the 3,4-methylenedioxyphenyl ring system has been replaced with a benzofuran ring. 6-APB is also the unsaturated benzofuran derivative of 6-APDB. While the drug never became particularly popular, it briefly entered the rave and underground clubbing scene in the UK before its sale and import were banned.

Pharmacology

6-APB is a triple monoamine reuptake inhibitor with K_i values of 117, 150 and 2698 nM for NET, DAT and SERT respectively as well as being a potent agonist for the 5-HT_2B receptor (K_i 3.7 nM). The subjective effects and structure–activity relationship suggest that it is also a releasing agent.

The agonism for 5-HT_2B makes it likely that 6-APB would be cardiotoxic with long term use, as seen in other 5-HT_2B agonists, such as fenfluramine and MDMA. 6-APB acts as an agonist of the 5-HT_2C receptor, which may be responsible for its appetite suppression. While 6-APB is an agonist at all three 5-HT₂ receptor subtypes, its affinity for 5-HT_2B is significantly higher. It is both more potent and more selective over other serotonin receptors than the reference agonist, BW723C86, which is commonly used for research into 5-HT_2B receptors.

APB

APB may refer to:

5-APB

5-APB (5-(2-aminopropyl)benzofuran, 1-benzofuran-5-ylpropan-2-amine, benzofury) is a triple monoamine reuptake inhibitor with K_i values of 180, 265 and 811 nM for NET, DAT and SERT respectively as well as being a potent agonist for the 5-HT_2A and 5-HT_2B receptors (K_i of 14nM at 5-HT_2B). This agonism for 5-HT_2B makes it likely that 5-APB would be cardiotoxic with long term use, as seen in other 5-HT_2B agonists such as fenfluramine and MDMA. The subjective effects and structure-activity relationship suggest that 5-APB is also a monoamine releasing agent.

5-APB is commonly found as the succinate and hydrochloride salt. The hydrochloride salt is 10% more potent by mass and doses should be adjusted accordingly.

5-APB is also an agonist of the 5-HT_2C receptor as well as a triple monoamine reuptake inhibitor. It has been sold as a designer drug since 2010.

Detection

A forensic standard of 5-APB is available, and the compound has been posted on the Forendex website of potential drugs of abuse. The US Department of Justice and DEA have also conducted studies concerning the detection of 5-APB.

2-Aminoethoxydiphenyl borate

2-Aminoethoxydiphenyl borate (2-APB) is a chemical that acts to inhibit both IP₃ receptors and TRP channels (although it activates TRPV1, TRPV2, & TRPV3 at higher concentrations). In research it is used to manipulate intracellular release of calcium ions (Ca²⁺) and modify TRP channel activity, although there its lack of specific effects make it less than ideal under some circumstances. Additionally, there is evidence that 2-APB acts directly to inhibit gap junctions made of connexin26 or connexin32. Increasing evidence showed that 2-APB is a powerful modifier of store-operated calcium channels (SOC) function, low concentration of 2-APB can enhance SOC while high concentration induces a transient increase followed by complete inhibition.

References