Glänzel Markus, Bültmann Ralph, Starke Klaus, Frahm August W
Chair of Pharmaceutical Chemistry, Albertstr. 25, 79104 i.Br., Freiburg, Germany.
Eur J Med Chem. 2003 Mar;38(3):303-12. doi: 10.1016/s0223-5234(02)01449-6.
The anthraquinone derivative Reactive Blue 2 (RB 2) is one of the most widely used P2-receptor antagonists, still claimed to be P2Y-selective. RB 2 is defined as a mixture of two constitutional isomers and commercially available in different identity and purity. A sample of RB 2, offered for sale by RBI, purchased from Biotrend, Köln, Germany, was chromatographically purified and identified by 1H- and 13C-NMR studies as a 35:65 mixture of the terminal ring F meta and para constitutional isomers. The two constitutional isomers of RB 2 were synthesised and tested alongside with the ortho isomer Cibacron Blue 3GA (CB 3GA) on contractions of the rat vas deferens (RVD) elicited by alpha,beta-methylene ATP (alpha,beta-MeATP), mediated by P2X(1)-receptors, and relaxations of the carbachol-precontracted guinea pig taenia coli elicited by adenosine 5'-O-(2-thiophosphate) (ADPbetaS), mediated by P2Y(1)-like-receptors. All compounds inhibited the alpha,beta-MeATP induced contraction of the RVD and the ADPbetaS induced relaxation of the carbachol precontracted guinea-pig taenia coli. The IC(50)-values at P2X(1)-R were 9.1 microM for CB 3GA, 28.4 microM for RB 2, 19.7 microM for RB 2 meta, and 35.5 microM for RB 2 para. The IC(50)-values at P2Y(1)-like-R were 17.4 microM for CB 3GA, 7.7 microM for RB 2, 12.0 microM for RB 2 meta, and 2.6 microM for RB 2 para. The results clearly show that neither RB 2 as a mixture nor the pure ortho and meta isomer are P2Y(1)-like- versus P2X(1)-selective antagonists. In contrast the pure para-isomer of RB 2 is a moderately P2Y(1)-like- versus P2X(1)-selective antagonist.
蒽醌衍生物活性蓝2（RB 2）是使用最广泛的P2受体拮抗剂之一，仍被认为是P2Y选择性的。RB 2被定义为两种构造异构体的混合物，以不同的身份和纯度在市场上销售。从德国科隆的Biotrend购买的、由RBI出售的RB 2样品，经色谱纯化，并通过1H-和13C-NMR研究鉴定为末端环F间位和对位构造异构体的35:65混合物。合成了RB 2的两种构造异构体，并与邻位异构体汽巴克隆蓝3GA（CB 3GA）一起，测试它们对由α,β-亚甲基ATP（α,β-MeATP）引起的大鼠输精管（RVD）收缩（由P2X(1)受体介导），以及对由5'-O-(2-硫代磷酸)腺苷（ADPβS）引起的卡巴胆碱预收缩的豚鼠结肠带松弛（由P2Y(1)样受体介导）的影响。所有化合物均抑制α,β-MeATP诱导的RVD收缩和ADPβS诱导的卡巴胆碱预收缩的豚鼠结肠带松弛。在P2X(1)受体处的IC(50)值，CB 3GA为9.1微摩尔，RB 2为28.4微摩尔，RB 2间位为19.7微摩尔，RB 2对位为35.5微摩尔。在P2Y(1)样受体处的IC(50)值，CB 3GA为17.4微摩尔，RB 2为7.7微摩尔，RB 2间位为12.0微摩尔，RB 2对位为2.6微摩尔。结果清楚地表明，无论是作为混合物的RB 2，还是纯的邻位和间位异构体，都不是P2Y(1)样相对于P2X(1)的选择性拮抗剂。相比之下，RB 2的纯对位异构体是一种适度的P2Y(1)样相对于P2X(1)的选择性拮抗剂。
