新型芳香吲唑酮类化合物的合成与表征

以p-取代苯胺为原料,经重氮化反应后再与2-氯乙酰乙酸乙酯反应制得(Z)-4-[2-(1-氯-2-乙氧基-2-羰亚甲基)肼基]-取代苯(2a～2i);在无水乙醇中,2a～2i分别与5,5-二甲基-1,3-环己二酮发生环化反应合成了9个新型的芳香吲唑类化合物(3a～3i),其结构经1H NMR和MS表征.     

新型噻唑烷二酮衍生物的合成及其抑制酪氨酸酶活性研究

以噻唑烷二酮和取代芳香醛为原料,通过缩合反应合成了一系列新型噻唑烷二酮衍生物（1~11）,其结构经¹H NMR、¹³C NMR、 IR、 MS（ESI）和元素分析表征,并考察了1~11对酪氨酸酶的抑制活性。结果表明：所有化合物都具有一定的酪氨酸酶抑制活性,部分化合物对酪氨酸酶的抑制活性强于阳性对照曲酸。初步构效关系分析表明：5-(4-羟基-3-甲氧基苯亚甲基)-2,4-噻唑烷二酮(8)抑制效果最强(IC₅₀=0.12±0.03μM)。选择化合物8进行了抑制动力学和分子对接研究。结果表明：化合物8为竞争性抑制剂,其抑制常数K_i为0.54 μM; 8能够和酪氨酸酶铜离子活性中心相互作用,从而抑制酪氨酸酶活性。      

新型2-硫代喹唑啉二酮类PARP-1抑制剂的合成及其生物活性

分别以苯胺(衍生物)与苯甲醛(衍生物)为起始原料,合成关键中间体5-(6-氟-4-氧代-2-硫-3,4-二氢-2H-喹唑啉基-1-甲基）苯甲酸（6a）、 2-氟-5-(6-氟-4-氧代-2-硫-3,4-二氢-2H-喹唑啉-1-基甲基)苯甲酸（6b）和2-氟-5-｛［4-氧代-2-硫-3,4-二氢吡啶并[2,3-d]嘧啶-1(2H)-基］甲基］｝苯甲酸（6c）;再经多步反应合成了14个含喹唑啉二酮骨架的PARP-1抑制剂(8a~8n),其结构经¹H NMR和MS(ESI)表征。体外活性测试结果显示：化合物1-{3-[4-(环戊烷羰基)-3-甲基哌嗪-1-羰基]-4-氟苄基}-6-氟-2-硫代-2,3-二氢-1H-喹唑啉-4-酮（8g）和1-{3-[4-(环己烷羰基)-3-甲基哌嗪-1-羰基]-4-氟苄基}-6-氟-2-硫代-2,3-二氢-1H-喹唑啉-4-酮（8h）对人乳腺癌细胞MDA-MB-436的抑制活性最强,IC₅₀分别为64.3 nmol·L^-1和86.4 nmol·L^-1,与阳性对照药奥拉帕尼的抑制活性处于同一数量级（IC₅₀=48.3 nmol·L^-1)。     

新型L-酪氨酸二肽衍生物的合成及其抗肿瘤活性

以L-酪氨酸甲酯盐酸盐和对羟基苯甲酸（PHBA）为原料,经缩合、水解和亲核取代反应,设计并合成了9个新型的L-酪氨酸二肽衍生物（3b和4a~4h）,其结构经¹H NMR、 ¹³C NMR和MS（ESI）表征。采用MTT法评价了化合物对白血病细胞（K562）、人肺癌细胞（A549）和人肝癌细胞（HepG2）的体外抑制活性。结果表明：N-[N-(4-苄氧基-苯甲酰基)-O-二甲氨基丙基-L-酪氨酰基]-L-苯丙氨醇(4e)对HepG2和K542细胞的抑制活性均高于阳性对照药阿霉素,IC₅₀分别为0.41和11.77 μmol·L^-1。     

新型氨基喹唑啉化合物的合成及其抗肿瘤活性

以2-氰基-4-硝基苯胺为原料,设计并合成了6个新型的氨基喹唑啉类化合物(5a~5c和6a~6c),其结构经1H NMR,13C NMR和ESI-MS表征。初步的抗肿瘤活性测定结果表明,6-(4-甲酸甲酯苯甲酰胺基)-4-(4-甲基-3-三氟甲基苯胺基)喹唑啉(5b)对人乳腺癌细胞MDA-MB-231和人宫颈癌细胞HELA的抑制活性较好,其IC50分别为4.50μM和3.3μM,优于阳性对照药Gefitinib。     

新型1,4-二苯并二氮杂酮类衍生物的合成及其抗癌活性

以取代邻硝基苯甲酸为起始原料,与二氯亚砜反应制得邻硝基苯甲酰氯,再与苯胺在碱性条件下反应制得酰胺衍生物(6a~6d);以醋酸钯为催化剂,6a~6d经NBS溴代制得溴代衍生物(7a~7d); 7a~7d依次经N-烷基化反应,还原反应和分子内C-N键环合反应合成了10个新型的1,4-二苯并二氮杂酮类化合物(10a~10j),产率61%~78%,其结构经¹H NMR, ¹³C NMR和HR-MS(ESI)表征。初步体外活性测试结果表明:10a~10j对非小细胞肺癌细胞（A549）,人乳腺癌细胞（MDA-MB-231）和宫颈癌细胞(HeLa)均有抑制作用。其中,10g和10i对A549, 10g对MDA-MB-231, 10h和10i对HeLa的抑制率大于50%。     

一种新型枝化聚乙二醇的合成

以谷氨酸作为中心分子,首先对谷氨酸的氨基进行Boc保护,然后在4-二甲基氨基吡啶-二环己基碳二亚胺催化体系的作用下,将两条线性的单甲氧基聚乙二醇(mPEG)链连接到谷氨酸的两个羧基上,合成出含有两条聚乙二醇(PEG)链及一个活性氨基的新型枝化PEG[Glu(PEG)2],其结构经1H NMR,IR,GPC和VPO表征。     

新型黄烷酮的合成及其抑菌活性

以异香草醛和2,4,6-三羟基苯乙酮为起始原料,经过C-异戊烯基化、选择性地甲基化或甲氧甲基化、羟醛缩合、催化环化与加成共6步反应,首次合成了两个新型黄烷酮—5,7,4'-三甲氧基-3'-羟基-8-(3”-羟基-3”-甲基-丁基)黄烷酮(1a)和5,7,4'-三甲氧基-3'-羟基-8-(3”,甲氧基-3”-甲基-丁基)...     

6,7-亚甲二氧基-9-甲基-1(2H,4H)-吖啶酮衍生物的合成

以5-芳基-1,3-环基环己二酮为原料合成了8个未见报道的吖啶酮衍生物,其结构均经元素分析,IR和^1H NMR光谱确证。其中3-呋喃基-6,7-亚甲二氧基-9-甲基-1(2H,4H)-吖啶醇对一些肿瘤细胞有抑制作用。     

基于结构的新型CDK7抑制剂的设计、合成及其抗肿瘤活性

根据细胞周期依赖性激酶7(CDK7)的蛋白结构, 利用Discovery Studio 2.1程序包中的LigandFit模块建立了CDK7抑制剂的分子对接模型, 采用受试者工作特征曲线(ROC)方法选择LigScore2为最佳打分函数(ROC曲线下的面积为0.95), 并验证了该模型的准确性. 利用该模型对设计的化合物与CDK7蛋白进行对接分析, 得到了2个打分最高的化合物16、17, 进而通过13步的合成路线, 以中等至高的收率得到目标化合物, 并测定其体外抗肿瘤活性. 结果表明, 所合成的化合物对急性前髓细胞性白血病细胞(HL60)、鼻咽癌细胞(KB)、肝肿瘤细胞(SMMC-7721)、结肠腺癌细胞(HCT-116)、肺癌细胞(A549)细胞株均有抑制作用(IC50值为0.84-19.70 μmol·L-1), 其中化合物16对HL60细胞株的IC50值最低, 为0.84 μmol·L-1.     

Design,Synthesis and Pharmacological Evaluation of Novel Hsp90N-terminal Inhibitors Without Induction of Heat Shock Response

Heat shock protein 90 (Hsp90) is a potential oncogenic target. However, Hsp90 inhibitors in clinical trial induce heat shock response, resulting in drug resistance and inefficiency. In this study, we designed and synthesized a series of novel triazine derivatives ( A1 - 26 , B1 - 13 , C1 - 23 ) as Hsp90 inhibitors. Compound A14 directly bound to Hsp90 in a different manner from traditional Hsp90 inhibitors, and degraded client proteins, but did not induce the concomitant activation of Hsp72. Importantly, A14 exhibited the most potent anti-proliferation ability by inducing autophagy, with the IC₅₀ values of 0.1 μM and 0.4 μM in A549 and SK-BR-3 cell lines, respectively. The in vivo study demonstrated that A14 could induce autophagy and degrade Hsp90 client proteins in tumor tissues, and exhibit anti-tumor activity in A549 lung cancer xenografts. Therefore, the compound A14 with potent antitumor activity and unique pharmacological characteristics is a novel Hsp90 inhibitor for developing anticancer agent without heat shock response.     

Artificial Accelerators of the Molecular Chaperone Hsp90 Facilitate Rate‐Limiting Conformational Transitions

The molecular chaperone Hsp90 undergoes an ATP‐driven cycle of conformational changes in which large structural rearrangements precede ATP hydrolysis. Well‐established small‐molecule inhibitors of Hsp90 compete with ATP‐binding. We wondered whether compounds exist that can accelerate the conformational cycle. In a FRET‐based screen reporting on conformational rearrangements in Hsp90 we identified compounds. We elucidated their mode of action and showed that they can overcome the intrinsic inhibition in Hsp90 which prevents these rearrangements. The mode of action is similar to that of the co‐chaperone Aha1 which accelerates the Hsp90 ATPase. However, while the two identified compounds influence conformational changes, they target different aspects of the structural transitions. Also, the binding site determined by NMR spectroscopy is distinct. This study demonstrates that small molecules are capable of triggering specific rate‐limiting transitions in Hsp90 by mechanisms similar to those in protein cofactors.     

Synthesis and Biological Evaluation of Novobiocin Core Analogues as Hsp90 Inhibitors

Development of heat shock protein 90 (Hsp90) C‐terminal inhibitors has emerged as an exciting strategy for the treatment of cancer. Previous efforts have focused on modifications to the natural products novobiocin and coumermycin. Moreover, variations in both the sugar and amide moieties have been extensively studied, whereas replacements for the coumarin core have received less attention. Herein, 24 cores were synthesized with varying distances and angles between the sugar and amide moieties. Compounds that exhibited good anti‐proliferative activity against multiple cancer cell lines and Hsp90 inhibitory activity, were those that placed the sugar and amide moieties between 7.7 and 12.1 Å apart along with angles of 180°.     

Probing the influence of an allylic methyl group in zearalenone analogues on binding to Hsp90

By the replacement of an acetate with propionate by means of organic synthesis, a range of zearalenone analogues were prepared that feature an allylic methyl group. For the synthesis of the aliphatic region of the analogues, we used an asymmetric alkylation to yield pentenol derivatives 16 and ent‐ 16 . By means of hydroboration the corresponding aldehydes were secured. These were coupled with 2‐pentynol derivate 23 by means of a Carreira acetylide addition. Further routine steps led to the sulfones 29 and 45 , respectively. After merging them with 2‐bromobenzaldehyde 9 in a Julia–Kocienski reaction, metalation, carboxylation, and protecting‐group manipulations gave the seco acids 35 and 49 . By means of lactonization under Mitsunobu (alcohol activation) or Trost–Kita conditions (carboxyl activation), all four possible macrocyclic ketone stereoisomers were accessible. In all, considering various protecting‐group decorations, 16 analogues were obtained and tested for cytotoxicity (L929 mouse fibroblast cell line). Whereas most of the analogues were less active than zearalenone (IC₅₀=9.4 μM ), the resorcinol derivatives were comparable, with one stereoisomer ( 40 b ) being slightly more active (IC₅₀=6.6 μM ). These results were also reflected in the binding assays to Hsp90 in which 40 b showed a dissociation constant (K_d) value of 130 nM .     

Asymmetric Synthesis of Pochonin E and F,Revision of Their Proposed Structure,and Their Conversion to Potent Hsp90 Inhibitors

A concise and modular synthesis of pochonin E and F, and their epimers at C‐6 established the correct stereochemistry of these two natural products. Several members of the pochonin family have been shown to bind the heat shock protein 90 (Hsp90), which has been the focus of intense drug discovery efforts. Pochonin E and F as well as their epimers were derivatized into the corresponding pochoximes and further modified at the C‐6 position. Molecular dynamics simulations, docking studies, and Hsp90 affinity measurements were performed to evaluate the impact of these modifications.     

Synthesis and Biological Activity of 3-(Heteroaryl)quinolin-2(1H)-ones Bis-Heterocycles as Potential Inhibitors of the Protein Folding Machinery Hsp90

In the context of our SAR study concerning 6BrCaQ analogues as C-terminal Hsp90 inhibitors, we designed and synthesized a novel series of 3-(heteroaryl)quinolin-2(1H), of types 3, 4, and 5, as a novel class of analogues. A Pd-catalyzed Liebeskind–Srogl cross-coupling was developed as a convenient approach for easy access to complex purine architectures. This series of analogues showed a promising biological effect against MDA-MB231 and PC-3 cancer cell lines. This study led to the identification of the best compounds, 3b (IC₅₀ = 28 µM) and 4e, which induce a significant decrease of CDK-1 client protein and stabilize the levels of Hsp90 and Hsp70 without triggering the HSR response.     

Activation of Hsp90 Enzymatic Activity and Conformational Dynamics through Rationally Designed Allosteric Ligands

Hsp90 is a molecular chaperone of pivotal importance for multiple cell pathways. ATP‐regulated internal dynamics are critical for its function and current pharmacological approaches block the chaperone with ATP‐competitive inhibitors. Herein, a general approach to perturb Hsp90 through design of new allosteric ligands aimed at modulating its functional dynamics is proposed. Based on the characterization of a first set of 2‐phenylbenzofurans showing stimulatory effects on Hsp90 ATPase and conformational dynamics, new ligands were developed that activate Hsp90 by targeting an allosteric site, located 65 Å from the active site. Specifically, analysis of protein responses to first‐generation activators was exploited to guide the design of novel derivatives with improved ability to stimulate ATP hydrolysis. The molecules’ effects on Hsp90 enzymatic, conformational, co‐chaperone and client‐binding properties were characterized through biochemical, biophysical and cellular approaches. These designed probes act as allosteric activators of the chaperone and affect the viability of cancer cell lines for which proper functioning of Hsp90 is necessary.     

The succinct synthesis of AT13387, a clinically relevant Hsp90 inhibitor

AT13387 is an orally bioavailable clinical candidate developed to inhibit heat shock protein 90 (Hsp90). This article describes a modified synthetic route for the multi-gram production of AT13387 in 46% overall yield. The modified synthetic route is short, avoids stringent reaction conditions and difficult purifications, which led to an increase in overall yield.