1268328 MPY 4-mercaptopyridine 20 1268339 MPy methapyrilene 3 1268352 MPy maleimido-pyrene 2 1268332 MPy N-methylpyrrole 2 1268354 MPy 3-methyl-2-phenylpyridine 1 1268353 MPy magnetic pyrite 1 1268350 MPy melaminium dihydrogenpyrophosphate 1 1268351 MPy methyl pyridinium 1