The longest official word ever (1,913 letters) is the term for the formula C1289H2051N343O375S8
Methionylglutamin ylarginyltyrosylglu tamylserylleucylphenyl-
alanylalanylgluta minylleucyllysylgluta mylarginy llysyglutamyl-
gycylalanyl phenylalanylvalylp rolylphe nylalanylvaly lthreonyl-
leucylglycylaspa rtylprolylglyc yllisoleucylglu tamylglutaminyl -
serylleu cyllysylisoleu cylaspartylthr eonylleu cylisoleucyl-
glutamylalan ylglycylalany laspartylala nylleucylgluta mylleucyl-
glycylis oleucylprol ylphe nylalan ylseryla spartylp rolylle ucyl-
alanylaspart ylglycylprol ylthreonylisoleucylgluta minylasparagin yl-
alanylt hreonylleucylargin ylalanylphenylalany lalanylalanyl-
gl ycylvalylth reonylprolylal anylglutaminylc ysteinylpheny lalanyl-
glutamyl methionylleucylal anylleucylisoleucyl arginylgluta minyl-
lysylhist idylprolylthreonyli soleucylprolylisoleucyl glycylleucyl-
leucylmethiony ltyrosylalanylaspa raginylleucylvalylphe nylalanyl-
asparaginyll ysylglycylisoleucylasp artylglutamylphenylalanyl-
tyr osylalanylglutaminylcystei nylglutamyllysylvalylgly cylvalyl-
aspartylsrylva lylleucylvalylalanyla spartylvalylprolylval yl-
glutaminyl gluta mylserylalanylpr ol ylphenylalanyla rginylglu taminyl-
alanyl alanylleucylar ginylhistidylasparag inylvalylalanyl -
prolylisol eucylphenylal anylisoleucylcystei nylprolylprolylas partyl-
alanylas partylaspartylaspartyl leucylleucylargin ylglutaminyl-
i soleucyla lanylseryltyrosylgl ycylarginylglycyl tyrosylthreonyl-
tyrosylleuc ylleucylserylarginy lalanylglycylvalylth reonylglycyl-
alanylgl utamylasparag inylarginylalany lalanylleucyll eucyllysyl-
glu tamyltyrosyl asparaginylala nylalanylprolylpro lylleucylglutaminyl-
gly cylphenylalanylgly sylisoleucylserylal anylprolylaspa rtylglutaminyl -
valyllysyl alanylalanylisole ucylaspartylalanyl glycylalanylalan yl-
glycylalanyli soleucylserylglycyl serylalanylisoleuc ylvaly llysylisoleu cyl-
isoleuc ylglutamylgl utaminylhis tidylasparagin ylisoleucylglu tamyl-
proly lglutamyll ysylmethionylle ucylalanyl alanylleucylly sylvalylphenyl -
alanylval ylglutaminylproly lmethionyllysyl alanylalanylthreon ylarginy-
lserine.
