A compound having the structure: useful for treating hypertension, Pulmonary Arterial Hypertension (PAH), congestive heart failure, conditions resulting from excessive water retention, cardiovascular disease, diabetes, oxidative stress, endothelial dysfunction, cirrhosis, pre-eclampsia, osteoporosis or nephropathy.高血圧、肺動脈高血圧(PAH)、鬱血性心不全、過剰な水滞留に由来する障害、心血管病、糖尿病、酸化的ストレス、内皮機能不全、硬変、子癇前症、骨粗鬆症または腎障害を治療するのに有用な構造を有する化合物。【化1】