sib-1893 sib-1893 sib-1893 is a drug used in scientific research which was one of the first compounds developed that acts as a selective antagonist for the metabotropic glutamate receptor subtype mglur5. it has anticonvulsant and neuroprotective effects, and reduces glutamate release. it has also been found to act as a positive allosteric modulator of mglur4. sib-1893identifiers iupac name (e)-2-methyl-6-(2-phenylethenyl)pyridine cas number7370-21-0 ypubchem cid235382chemspider4470920 nunii4x2f5x24ukchemblchembl88612 nchemical and physical dataformulac14h13nmolar mass195.265 g·mol−13d model (jsmol)interactive image smiles c1ccccc1\c=c\c(nc2c)ccc2 inchi inchi=1s/c14h13n/c1-12-6-5-9-14(15-12)11-10-13-7-3-2-4-8-13/h2-11h,1h3/b11-10+ nkey:sisofuctxzksoq-zhacjkmwsa-n n ny (what is this?) (verify)