The outbreak of the COVID-19 pandemic caused by the SARS-CoV-2 has triggered intense scientific research into the possible therapeutic strategies that can combat the ravaging disease. One of such strategies is the inhibition of an important enzyme that affects an important physiological process of the virus. The enzyme, Guanine 7 Methyltransferase is responsible for the capping of the SARS-CoV-2 mRNA to conceal it from the host’s cellular defense. The study aims at computationally identifying the potential natural inhibitors of the SARS-CoV-2 GuanineN7 methyltransferase binding at the active site (Pocket 41). A library of small molecules was obtained from edible African plants and were molecularly docked against the SARS-CoV-2 Guanine-N7 methyltransferase (QHD43415_13. pdb) using the Pyrx software. Sinefungin, an approved antiviral drug which had a binding score of -7.6 kcal/ mol with the target was chosen as a standard. Using the molecular descriptors of the compounds, a virtual screening for oral availability was performed using the Pubchem and SWISSADME web tools. The online servers PKCSM and Molinspiration were used for further screening for pharmacokinetic properties and bioactivity respectively. The molecular dynamic simulation and analyses of the Apo and Holo proteins was performed using the GROMACS software on the Galaxy webserver. The lead compounds are Crinamidine, Marmesin and Sinensetin which are obtained from waterleaf, mango, and orange plants respectively. All the lead compounds performed better than the standard. Crinamidine is predicted to show the greatest inhibitory activity. Further tests are required to further investigate the inhibitory activities of the lead compounds.

中文翻译：

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在计算机上鉴定SARS-CoV-2鸟嘌呤-N7甲基转移酶的潜在天然抑制剂。

SARS-CoV-2引起的COVID-19大流行的爆发，引发了对可能与这种致命疾病作斗争的可能治疗策略的深入科学研究。这样的策略之一是抑制影响病毒重要生理过程的重要酶。鸟嘌呤7甲基转移酶负责对SARS-CoV-2 mRNA进行封端，以使其免受宿主的细胞防御作用。该研究旨在通过计算确定SARS-CoV-2鸟嘌呤N7甲基转移酶在活性位点结合的潜在天然抑制剂（袋41）。小分子文库是从可食用的非洲植物中获得的，并使用Pyrx软件与SARS-CoV-2鸟嘌呤-N7甲基转移酶（QHD43415_13。pdb）分子对接。辛芬净 选择与靶标的结合得分为-7.6 kcal / mol的批准抗病毒药物作为标准。使用化合物的分子描述子，使用Pubchem和SWISSADME网络工具对口服有效性进行了虚拟筛选。在线服务器PKCSM和Molinspiration分别用于进一步筛选药代动力学性质和生物活性。使用Galaxy Web服务器上的GROMACS软件对Apo和Holo蛋白进行了分子动力学模拟和分析。主要化合物是分别从水叶，芒果和橙子植物中获得的克利那丁，马梅辛和信那锡。所有铅化合物的性能均优于标准品。预测的啶虫nam显示最大的抑制活性。