Enzyme Inhibitors as Potential Anticancer and Antiviral

人工合成的DAG-内酯被设计为有效的PKC配体的范围继续扩大，目标是实现完全的同工酶专一性。今年的主要发现是：1)在固相载体上继续合成另外的96元文库，目的是最大限度地探索蛋白质-膜界面结合部位周围的化学空间。在文库成员的合成和质谱学表征方面的新的化学改进仍在继续。2)发现了第一个靶向包含C1结构域的非激酶蛋白的特定DAG-内酯。该化合物与RasGRP具有较低的纳摩尔结合亲和力，而与PK-C同工酶的结合活性较弱。人们正在探索这种选择性结合的生物学后果。3)以乙炔单元和苯环交替构成的“刚性棒”形式合成了具有侧链的DAG-内酯。初步的生物学研究表明，“刚性棒”的长度与用不同脂肪酸构建的人工膜的深度之间存在相关性。如果成功，这种方法将被用来将DAG-内酯专门转移到血浆膜上。4)合成的其中一个靶向DAG-内酯显示出非常强的刺激α-分泌酶活性的活性，这是治疗阿尔茨海默病的重要方法。B.黄酮乙酸类似物。合成了一种含叠氮基的合成类黄酮乙酸(FAA)，具有生物报道的功能，并显示出与母体FAA相同的活性。叠氮部分将被用于寻找与FAA活性有关的分子靶点。C.DNA甲基转移酶项目(ZeBularine)。研究表明，在T24膀胱癌和其他肿瘤细胞系中，ZeBularine 2(1H)-嘧啶酮核苷具有重新激活沉默的p16基因并使启动子区域去甲基化的能力。为了克服DNA参入率低的问题，我们合成了几种单磷酸前药2‘-脱氧泽布灵。最初的两种前药物测试都失败了，更多的类似物正在探索中。ZeBularine计划在今年年底前进入临床试验。

A. Protein Kinase C ProjectThe universe of synthetic DAG-lactones designed as potent PKC ligands continues to expand with the objective of achieving full isozyme specificity. The major findings this year are: 1) Syntheses of additional 96-member libraries on a solid-phase support continue with the intent to maximally explore the chemical space surrounding the binding site at the protein-membrane interface. New chemical improvements in the synthesis and characterization of the library members by mass spectrometry continue to be made.2) The first specific DAG-lactone targeting a non-kinase protein containing a C1 domain was discovered. The compound binds with low nanomolar binding affinity to RasGRP while showing weak binding activity for the PK-C isozymes. The biological consequences of this selective binding are being explored. 3) The synthesis of DAG-lactones with a side chain in the form of a "rigid rod" constructed with alternating acetylene units and benzene rings was completed Preliminary biological studies indicate a correlation between length of the "rigid rod" and depth of artificial membranes built with different fatty acids. If successful, this approach will be used to translocate DAG-lactones exclusively to the plasma membrane.4) One of the target DAG-lactones synthesized showed very potent activity in stimulating alpha-secretase activity, which is an important therapeutic approach in the treatment of Alzheimer's disease. B. Flavone acetic acid analogues. A synthetic analogue of flavone acetic acid (FAA) with an azido group designed to function as a biological reported was synthesized and shown to be as active as parent FAA. The azide moiety will be used to find the molecular target responsible for the activity of FAA. C. DNA Methyl Transferase Project (Zebularine). The ability of zebularine 2(1H)-pyrimidinone riboside to reactivate a silenced p16 gene and demethylate the promoter region in the T24 bladder carcinoma and other tumor cell lines was demonstrated. Several monophosphate pro-drug of 2'-deoxyzebularine were synthesized in order to overcome the low level of incorporation into DNA. The first two pro-drugs tested failed, and more analogues are being explored. Zebularine is scheduled to enter clinical trials before the end of the year.