T2R13 Activators

T2R13 include a variety of substances known for their bitter taste, which is a direct result of their interaction with this specific taste receptor. Denatonium, recognized as one of the most bitter substances, can strongly activate T2R13. This activation leads to the release of intracellular calcium, which is a hallmark of the receptor's functional activity. Similarly, quinine, a compound with a long history of use due to its bitter properties, engages T2R13 in a way that sets off the G-protein coupled receptor signaling cascade, culminating in the sensory perception of bitterness. Compounds such as propylthiouracil and chloroquine also have the ability to activate T2R13. Propylthiouracil, a thiourea derivative, and chloroquine, known for its distinctive bitter taste, initiate signaling pathways that involve changes in intracellular signaling, consistent with the receptor activation.

Saccharin and acesulfame K, although predominantly used for their sweetness, can activate T2R13, suggesting that their interaction with the receptor is capable of triggering the taste transduction pathway associated with bitterness. Sucralose is another sweetener that can activate T2R13, indicating that it can engage the same G-protein coupled receptor pathway. Beyond these, caffeine, a widely consumed bitter compound, naringin, a bitter flavonoid in grapefruit, aloin from aloe, and parthenolide from feverfew, are all known to activate T2R13. These compounds interact with T2R13, leading to the release of intracellular calcium, a critical step in taste signal transduction that ultimately results in the perception of bitterness.