PhTx-74

Philanthotoxin-7,4
Selective Antagonist of Various AMPA Receptors
    Cat #: P-120
    Alternative Name Philanthotoxin-7,4
  • Lyophilized Powder
  • Bioassay Tested
  • Source Synthetic
    MW: 507.54
    Purity: >99% (HPLC)
    Effective concentration 0.1-100 μM.
      • PhTx-74
    Chemical name (S)-N-[7-[(4-Aminobutyl)amino]heptyl]-4-hydroxy-α-[(1-oxobutyl)amino]benzenepropanamide dihydrochloride.
    Molecular formula C24H44Cl2N4O3.
    CAS No.: 401601-12-5, 1227301-51-0.
    Activity PhTx-74 (Philanthotoxin-7,4) is a synthetic polyamine analogue of the naturally occurring wasp venom toxin philanthotoxin-4,3,3. It is a potent and selective antagonist of certain isoforms of the AMPA type of ionotropic glutamate receptors1. PhTx-74 inhibited GluR1 and GluR3 homomers as well as GluR1/GluR2 where 100 μM inhibited nearly 100% of the glutamate evoked currents. However, up to 500 μM had no or little effect on GluR2 or GluR2/GluR3 channels1-2.
    Shipping and storage Shipped at room temperature. Product as supplied can be stored intact at room temperature for several weeks. For longer periods, it should be stored at -20°C.
    Solubility Water. Centrifuge all product preparations before use (10000 x g 5 min).
    Storage of solutions Up to one week at 4°C or six months at -20°C.
      • PhTx-74
        Alomone Labs PhTx-74 inhibits AMPA Receptor 1 (GluR1) expressed in Xenopus oocytes.
        Currents were recorded following stimulation with 10 µM glutamate (bar on top) at -100 mV holding potential. Reversible inhibitory effects of 0.1 to 10 µM of PhTx-74 (#P-120) are demonstrated, as indicated by the bars at the bottom.
    References - Scientific background
      • PhTx-74 (Philanthotoxin-7,4) is a synthetic polyamine analogue of the naturally occurring wasp venom toxin philanthotoxin-4,3,3. It is a potent and selective antagonist of certain isoforms of the AMPA type of ionotropic glutamate receptors1.

        PhTx-74 inhibited GluR1 and GluR3 homomers as well as GluR1/GluR2 where 100 µM inhibited nearly 100% of the glutamate evoked currents. However, up to 500 µM had no or little effect on GluR2 or GluR2/GluR3 channels1-2.

        PhTx-74 (5 µM) was used as a tool to demonstrate circadian changes in AMPAR subtypes functionally expressed in somatosensory cortex slices and the removal of some AMPAR during sleep.

        Indeed, EPSPs were significantly depressed by PhTx-74 only after dark episodes3. As a measure for changes in AMPAR subunit composition after cocaine administration, PhTx-74 was used in synaptic transmission evaluation. AMPAR EPSCs from neurons treated earlier with cocaine showed increased sensitivity to bath application of 100 µM PhTx-74 compared with vehicle-treated cells, suggesting an increased contribution of GluR1-containing AMPARs to synaptic transmission after cocaine4.

        PhTx-74 was used to evaluate the effects of transmembrane AMPAR regulatory proteins (TARPs) on AMPAR conductance; 100 µM PhTx-74 blocked GluA2/A4 currents to a different degree depending on the auxiliary TARP present5.

    Target AMPA receptors
    Last update: 24/09/2019

    PhTx-74 (#P-120) is a highly pure, synthetic, and biologically active compound.

    For research purposes only, not for human use