Indolequinone 및 Benzo[d]oxazoline 유사체의 합성 및 항진균 작용 연구

Abstract

Quinonoid 유도체들은 항진균, 항암, 항균, 항말라리아, nitric oxide synthase 저해작용 등 다양한 생리활성을 나타낸다. 본 연구에서는 quinone 유도체 중 우수한 생리활성이 예상되는 1H-pyrrolo[3,2-g]isoquinoline-4,9- diones, 5H-pyrrolo[3,2-g]quinazoline-5,9-diones 및 2-amino-5-hydroxy-4- mercaptofuroisoquinolines 유도체와 새로운 기전의 항진균 작용을 갖는 benzo[d]xazoline 유도체를 새로이 합성하여 그 생리활성을 검색하였다. 신약 개발의 중요한 lead compound인 isoquinolinedione을 oxychlorination시켜 얻은 6,7-dichloroisoquinoline-5,8-dione 에 methyl cyanoacetate를 가하여 methyl기와 cyano acethyl기가 치환된 methyl 2-(7-chloro-5,8-dihydro-5,8- dioxoisoquinolin-6-yl)-2-cyanoacetate를 합성하였다. 여기에 arylamine 또는 aliphatic amine을 첨가하여 NQNs 유도체 11개를 합성하였다. 또한 6,7-dichloro-5,8-quinazolinedione에 ethyl cyanoacetate를 가하여 ethyl기와 cyanoacetyl기가 치환된 ethyl 2-(7-chloro-5,8-dihydro-5,8-dioxoquinazoline- 6-yl)-2-cyanoacetate를 합성하였다. 여기에 arylamine을 첨가하여 DNQs 유도체 5개를 합성하였다. 기존의 hydroxybenzofuran 유사체들은 fungal Nmt inhibitors로 알려져 있으며 이는 기존 항진균제들과 다른 약리기전을 가지므로 최근 항진균제들이 가지고 있는 단점을 극복할 수 있을 것으로 기대되고있다. Isoquinoline 구조를 포함한 모핵에 methyl cyanoacetate를 가하여 불안정한 중간 유도체를 얻고 여기에 곧바로 arylthiols를 가하여 furan ring을 포함하고 있는 furo[2,3-f]isoquinoline 구조의 NQSs 유도체 8개를 합성하였다. 2-Ethylbenzo[d]oxazoline을 bromination하여 얻은 모핵에 arylamine을 가하여 ONQNs 유도체 13개를 합성하였고, arylthiols와 aliphatic thiols를 가하여 ONQSs 유도체 5개를 얻었다. Benzoxazoline 구조는 cell cycle 조절에 관여하는 CDC25s를 억제하는 것으로 알려져 있으며, 세포분열을 저해하여 항암제로의 개발이 기대되는 한편, 항진균 작용도 가질 것으로 예상된다. 합성한 유도체 (NQNs, NQSs, ONQNs, ONQSs, DNQs)들에 대해서 6가지 병원균주인 C. albicans, C. tropicalis, C. krusei, C. neoformans, A. niger 및 A. flavus 에 대한 항진균 작용을 검색하였다. 각 화합물에 대한 MIC (minimum inhibitory concentration)는 액체 배지 희석법 (two fold broth dilution method)으로 하였고 대조 약물로는 fluconazole, fluorocytosine을 사용하였다. NQNs 유도체들의 경우, 대체적으로 C. albicans와 C. tropicalis , C. krusei, C. neoformans 네 균주에 대해 좋은 약효를 나타냈고, 몇몇 약물은 모든 균주에 대해 좋은 항진균 효과를 나타내기도 했다. 모든 약물이 여섯 균주에 대해 fluconazole보다 나은 효과를 나타냈다. NQSs 유도체의 경우, NQS2 (4-CH₃), NQS5 (4-Br)을 제외한 나머지 약물은 모든 균주에 대해 약효가 좋았으며, 특히 NQS1 (4-H)과 NQS8 (3-F)는 A. niger을 제외한 나머지 균에 대해 fluorocytosine과 비슷하거나 더 나은 효과를 나타냈다. ONQNs의 항진균 작용을 검색한 결과, 대체적으로 모든 약물이 fluconazole과 비슷하거나 나은 효과를 보였으며, 특히 ONQN1 (4-H)와 ONQN12 (4-Br)은 모든 균주에 대해 fluorocytosine과 비슷하거나 뛰어난 약효를 보였다. 주로 halogen이 치환된 유도체가 항진균 효과가 좋았다. ONQs 유도체들은 모든 균에 대해 fluconazole과 비슷하거나 나은 효과를 나타냈지만, fluorocytosine 만큼 뛰어난 약효를 보이는 약물은 없었다. DNQs 유도체의 경우, C. tropicalis 에 대해 약간 더 좋은 효과를 보였을 뿐, 눈에 띄게 좋은 항진균 효과를 나타내는 물질은 없었다.;Quinones have various pharmacological activities such as antifungal, anticancer and antimalarial activities. Especially, compounds containing the heterocyclic quinone group represent an important class of biologically active compounds. Based on this consideration, indolequinone and hydroxybenzofuran, benzo[d]oxazoline derivatives were synthesized and evaluated for their antifungal activites. Hydroxybenzofuran antifungal agents have been reported to be fungal Nmt inhibitors. Fungal Nmt is a potential target enzyme for the development of novel fungicidal drugs having a broad antifungal spectrum. In addition, the Nmt inhibitors might overcome the drawbacks of current antifungal drugs, such as resistance or drug-drug interactions. Based on this consideration, various hydroxybenzofuran analogues were synthesized and evaluated for their antifungal activites. Indolequinone agents are a unique class of bioreductive cytotoxins that can function as dual substrates for both one/two-electron reductases. Indolequinone derivatives have been reported to have antifungal, anticancer activities. Based on this consideration, indolequinone stucture might be an important lead compound. Thus various indolequinone analogues were synthesized and evaluated for their antifungal activites. Methyl 2-(7-chloro-5,8-dihydro-5,8-dioxoisoquinolin-6-yl)-2-cyanoacetate (NQC) was obtained by substitution of 6,7-dichloroisoquinoline-5,8-dione with methyl cyanoacetate. Methyl 2-amino-4,9-dihydro-4,9-dioxo-1H- pyrrolo[3,2-g]isoquinoline-3-carboxylate (NQNs) and methyl 2-amino-5- hydroxy-4-mercaptofuro[2,3-f]isoquinoline-3-carboxylate (NQSs) were obtained by substitution of NQC with the appropriate arylamines and arylthiols. 5,6-Dibromo-2-ethylbenzo[d]oxazole-4,7-dione (ONQBr) was obtained by substitution of 2-ethylbenzo[d]oxazole-4,7-dione (ONQ3) with bromine. 5-Bromo-2-ethylbenzo[d]oxazole-4,7-dione (ONQNs) and 5,6-bismercapto- 2-ethylbenzo[d]oxazole-4,7-dione (ONQSs) were obtained by substitution of ONQBr with the appropriate arylamines and arylthiols. Ethyl 2-(7-chloro-5,8-dihydro-5,8-dioxoquinazolin-6-yl)-2-cyanoacetate (QCC) was obtained by substitution of 6,7-Dichloro-5,8-quinazolinedione (QC) with ethyl cyanoacetate. Ethyl 7-amino-8,9-dihydro-5,9-dioxo-5H- pyrrolo[3,2-g]quinazoline-6-carboxylate (DNQs) derivatives were obtained by substitution of QCC with the appropriate arylamines. The antifungal activities of all the compounds have synthesized were evaluated using the two fold broth dilution method against C. albicans, C. tropicalis, C. neoformans, C. krusei, A. flavus and A. niger. Their minimum inhibitory concentration (MIC) values were determined and compared with positive controls, fluconazole and fluorocytosine. Among newly synthesized compounds, methyl 2-amino-4,9-dihydro-4,9-dioxo-1H- pyrrolo[3,2-g]isoquinoline-3-carboxylate (NQNs) and methyl 2-amino-5- hydroxy-4-mercaptofuro[2,3-f]isoquinoline-3-carboxylate (NQSs) and 5-bromo-2-ethylbenzo[d]oxazole-4,7-dione (ONQNs) generally showed relatively potent antifungal activities compared to fluconazole and fluorocytosine.