A novel series of imidazo[2,1-b]thiazole-sulfonyl piperazine conjugates (9aa-ee) has been synthesized and evaluated for carbonic anhydrase (CA, EC 4.2.1.1) inhibitory potency against four isoforms: The cytosolic isozyme hCA I, II and trans-membrane tumor-associated isoform hCA IX and hCA XII, taking acetazolamide (AAZ) as standard drug, using a stopped flow CO₂ hydrase assay. The results revealed that most of the compounds showed selective activity against hCA II whereas none of them were active against hCA I, IX, XII (K_i > 100 µM). The physiologically dominant cytosolic isoform hCA II was inhibited by these molecules with inhibition constants in the range of 57.7–98.2 µM. This new derivative, thus, selectively inhibits hCA II over the hCA I, IX, XII isoforms, which may be used for further understanding the physiological roles of some of these isoforms in various pathologies.

中文翻译：

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咪唑并[2,1-b]噻唑基磺酰哌嗪作为新型碳酸酐酶Ⅱ抑制剂的合成及生物评价。

合成了一系列新的咪唑并[ 2,1- b ]噻唑-磺酰基哌嗪共轭物（9aa-ee），并评估了其对四种同工型的碳酸酐酶（CA，EC 4.2.1.1）的抑制力：胞质同工酶hCA I， II和跨膜肿瘤相关的亚型hCA IX和hCA XII，以乙酰唑胺（AAZ）为标准药物，采用停流CO ₂氢化酶测定法。结果表明，大多数化合物对hCA II具有选择性活性，而对hCA I，IX，XII（K _i> 100 µM）。这些分子可抑制生理上占优势的胞质亚型hCA II，其抑制常数为57.7–98.2 µM。因此，这种新的衍生物相对于hCA I，IX，XII同工型选择性抑制hCA II，可用于进一步了解这些同工型中的某些在各种病理学中的生理作用。