A compound of Formula: wherein ------, independently, stands for a single bond or a double bond; R 1, on each occurrence, independently is (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, (C 1 -C 3)alkoxy, cyano, halogen, aryl-O-, aryl, or a 5- to 6-membered heteroaryl; or two R 1 groups, together with the bonds they are attached to, form a 5 to 8 membered cyclic ring; n is 0, 1, 2, 3, or 4; Each of a1, a2, and a3 is 0 or 1, wherein two of a1, a2, and a3 are 0, and the other is 1; R 2 is hydrogen, (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, or (C 1 -C 3)alkoxy; E is absent and G is (C 1 -C 3)alkylene, or (C 2 -C 3)alkenylene; A is a bond or n' is 0, 1, or 2; R 4 and R 5, on each occurrence, independently are hydrogen, (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, or (C 1 -C 3)alkoxy; X is aryl or heteroaryl, wherein said aryl and said heteroaryl are optionally substituted by one to five R 3 groups and/or one R c group; R 3, on each occurrence, independently is hydrogen, halogen, (C 1 -C 3)alkyl-C O-, (C 1 -C 3)alkyl-C -,(C 1 -C 3)alkyl-C N(R 6), N(R 6) 2 -, (R 6) 2 NC -, (R 6) 2 N(C 1 -C 5)alkoxy, (R 6) 3 N ⊕ (C 1 -C 5) alkoxy, hydroxyl, cyano, or a sugar moiety, (C 1 -C 3)alkoxy optionally substituted by one or more same or different halogen or thio groups, or (C 1 -C 3)alkyl optionally substituted by one or more same or different halogen or hydroxyl groups; R 6, on each occurrence, independently is hydrogen, (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, or (C 1 -C 3)alkoxy; R a on each occurrence, independently is hydrogen, (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, (C 1 -C 3)alkoxy, cyano, halogen, aryl, or aryl-O-; R c is hydrogen, (C 1 -C 5)alkoxy, or (C 1 -C 5)alkyl, wherein said (C 1 -C 5)alkoxy and said (C 1 -C 5)alkyl are optionally substituted by one or more same or different substituents selected from the group of hydroxyl, (C 1 -C 3)alkoxy, halogen, and thio; and b is 0, 1, 2, 3, or 4; or a pharmaceutically acceptable salt, solvate, hydrate, clathrate, polymorph, stereoisomer, enantiomer, or combination thereof. ------, independently, stands for a single bond or a double bond; R 1, on each occurrence, independently is (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, (C 1 -C 3)alkoxy, cyano, halogen, aryl-O-, aryl, or a 5- to 6-membered heteroaryl; or two R 1 groups, together with the bonds they are attached to, form a 5 to 8 membered cyclic ring; n is 0, 1, 2, 3, or 4; Each of a1, a2, and a3 is 0 or 1, wherein two of a1, a2, and a3 are 0, and the other is 1; R 2 is hydrogen, (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, or (C 1 -C 3)alkoxy; E is absent and G is (C 1 -C 3)alkylene, or (C 2 -C 3)alkenylene; A is a bond or n' is 0, 1, or 2; R 4 and R 5, on each occurrence, independently are hydrogen, (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, or (C 1 -C 3)alkoxy; X is aryl or heteroaryl, wherein said aryl and said heteroaryl are optionally substituted by one to five R 3 groups and/or one R c group; R 3, on each occurrence, independently is hydrogen, halogen, (C 1 -C 3)alkyl-C O-, (C 1 -C 3)alkyl-C -,(C 1 -C 3)alkyl-C N(R 6), N(R 6) 2 -, (R 6) 2 NC -, (R 6) 2 N(C 1 -C 5)alkoxy, (R 6) 3 N ⊕ (C 1 -C 5) alkoxy, hydroxyl, cyano, or a sugar moiety, (C 1 -C 3)alkoxy optionally substituted by one or more same or different halogen or thio groups, or (C 1 -C 3)alkyl optionally substituted by one or more same or different halogen or hydroxyl groups; R 6, on each occurrence, independently is hydrogen, (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, or (C 1 -C 3)alkoxy; R a on each occurrence, independently is hydrogen, (C 1 -C 3)alkyl, hydroxy(C 1 -C 3)alkyl, (C 1 -C 3)alkoxy, cyano, halogen, aryl, or aryl-O-; R c is hydrogen, (C 1 -C 5)alkoxy, or (C 1 -C 5)alkyl, wherein said (C 1 -C 5)alkoxy and said (C 1 -C 5)alkyl are optionally substituted by one or more same or different substituents selected from the group of hydroxyl, (C 1 -C 3)alkoxy, halogen, and thio; and b is 0, 1, 2, 3, or 4; or a pharmaceutically acceptable salt, solvate, hydrate, clathrate, polymorph, stereoisomer, enantiomer, or combination thereof.