Inhibition of SARS-CoV 3CL protease by flavonoids

Jo, Seri; Kim, Suwon; Shin, Dong Hae; Kim, Mi-Sun

Coronaviruses (CoVs) are single-stranded RNA viruses with large, enveloped and positive senses that can infect both animals and humans 1 . CoVs, along with Artierivirdae and Roniviridae, belong to the Coronaviridae family in the order Nidovirales. These CoVs can infect various hosts, including avian, swine and humans. Human coronaviruses (HCoVs) represent a major group of CoVs associated with various respiratory diseases from common cold to serious pneumonia and bronchiolitis 2 . Today, HCoVs are recognised as one of the fastest-evolving viruses derived from their characteristic high genomic nucleotide replacement rates and recombination 3 . Severe Acute Respiratory Syndrome (SARS), the first confirmed atypical pneumonia in China's Guangdong province, has spread to several countries. The most common symptoms of SARS include coughing, high fever (>38 C), chills, convulsions, headaches, dizziness and progressive radiographic changes of the chest and lymphopenia 4 . The severity of the disease shows a death rate of about 3% to 6%, although this rate could rise up to 43% to 55% for senior citizens older than 60 years 5 . The primary epidemic of SARS was eventually controlled, but a SARS CoV-like virus was detected in Chinese bats 6, 7 . Besides, a recent pandemic of middle east respiratory syndrome (MERS) caused by a novel coronavirus MERS-CoV raises fear of possible recurrence of SARS or related dangerous diseases 8, 9 . Since there is no vaccine and effective therapy for these viral infections, developing anti-SARS drugs against future outbreaks remains a formidable challenge.