definiens: means any member of the class of substituted 4 - H chromenes, analogs and derivatives set forth below : A compound of FonTIula 1 : ( I ) or a pharmaceutically acceptable sal t or prodrug thereof, wherei n : X is 0, S or NR6 wherein R6 is hydrogen or an optionally substituted alkyl ; Y is CN, COR7, C02R7, or CONRxRy, wherein R7, Rx and Ry are independently hydrogen, C1 - 1O alkyl, haloalkyl, aryl fused aryl, carbocyc lic, a heterocycli c group, a heteroaryl group, alkenyl, alkynyl, arylalkyl, arylalkenyl, arylalkynyl, heteroarylalkyl, heteroarylalkenyl, heteroarylalkynyl, carbocycloalkyl, heterocycJoalkyl, hydroxyalkyl, or arninoalkyl ; or Rx and Ry are taken together with the nitrogen to fOlm a heterocycle ; Z is NR8R9, NHCOR8, N(COR8)2, N(COR8)(COR9 ), N = CHOR8, or N = CHR8, wherein R8 and R9 are independently H, Cl-4 alkyl or aryl, or RS and R9 are combined together with the group attached to them to fOlm a heterocycle ; R5 is hydrogen or C1 - 10 alkyl ; A is optionally substituted and is aryl, heteroary1, saturated carbocyc lic, partially saturated carbocyclic, saturated heterocyclic, partially saturated heterocyclic, arylalkyl or heteroarylalkyl ; and B is an optionally substituted monocyclic or bicyC\ic aromatic or monocyclic orbicyclic heteroaromati c ling system ; with the proviso that when B, together with the pyran ring to which it is fused, fOlms a tJicyclic ring system selected from the group consisting of 4H­naphtopyrans, 4H - quinopyrans and 4H - isoquinopyrans, and A is phenyl, naphthyl, thienyl, pyridiy1, benzothieny 1, quinoliny 1, benzofuranyl, or benzimidazolyl, then A is substituted at three or more positions by other then hydrogen