| abstract |
Compounds represented by general formula (I) or salts thereof which cause a morphological change in trabecular cells to thereby lower intraocular pressure. In the formula, R1 represents H, lower alkyl, hydroxy, lower alkoxy or halogeno; R?2, R3 and R4¿ represent each H or lower alkyl; and --- represents a single or double bond, provided that when R3 and/or R4 are hydrogen, then the amino may be protected. |