Table 2.
The most common heterocycles with five atoms found in the molecular structure of antibacterial agents (HBA—Hydrogen Bond Acceptor Count, HBD—Hydrogen Bond Donor Count, MW—Molecular Weight) [21].
| Five-Membered Heterocycles |
Heteroatom (s) | Chemical Structure |
MW (g/mol) | HBA | HBD |
|---|---|---|---|---|---|
| Pyrrolidine | N |
|
71.12 | 1 | 1 |
| Imidazole | N(2) |
|
68.08 | 1 | 1 |
| 1,2,3-Triazole | N(3) |
|
69.07 | 2 | 1 |
| Tetrazole | N(4) |
|
70.05 | 3 | 1 |
| Furan | O(1) |
|
68.07 | 1 | 0 |
| 1,3-Oxazolidine | N(1),O(1) |
|
73.09 | 2 | 1 |
| 1,3-Oxazole | N(1),O(1) |
|
69.06 | 2 | 0 |
| 1,2-Oxazole (Isoxazole) | N(1),O(1) |
|
69.06 | 2 | 0 |
| Thiophene | S(1) |
|
84.14 | 1 | 0 |
| 1,3-Thiazolidine | N(1),S(1) |
|
89.6 | 2 | 1 |
| 1,3-Thiazole | N(1),S(1) |
|
89.16 | 2 | 1 |
| 1,2,4-Thiadiazole | N(2),S(1) |
|
86.12 | 3 | 0 |
| 1,3,4-Thiadiazole | N(2),S(1) |
|
86.12 | 3 | 0 |