Lee, Ba Wool Ha, Thi Kim Quy Park, Eun Jin Cho, Hyo Moon Ryu, Byeol Doan, Thi Phuong Lee, Hee Ju Oh, Won Keun 2024-01-19T15:32:57Z 2024-01-19T15:32:57Z 2022-01-10 2021-01-15 0022-3263 https://pubs.kist.re.kr/handle/201004/117517 In the search for antiviral cyclopeptides against influenza A virus, five unprecedented Caryophyllaceae-type cyclopeptides (1-5) were isolated from the leaves of Melicope pteleifolia. Their chemical structures and absolute configurations were unambiguously determined by means of advanced Marfey's analysis and comprehensive spectroscopic analyses including two-dimensional nuclear magnetic resonance and MS/MS fragmentation. Interestingly, compounds 3-5 contain an unusual heterocycle, a 3a-hydroxypyrroloindole moiety, which was biosynthetically formed by a nucleophilic cyclization from the least abundant amino acid, tryptophan, precursor and has aroused a great interest in the aspect of chemical diversity and biological activity. All isolates (1-5) were evaluated for their protective effects against influenza A viruses H1N1 and H9N2 in MDCK cells. All isolated cyclopeptides exhibited strong anti-influenza activity, especially against H1N1. Compound 3 showed the most potent CPE inhibition effect, which was stronger than that of the positive control ribavirin against H1N1, with an EC50 (mu M) of 2.57 +/- 0.45 along with higher selectivity. English AMER CHEMICAL SOC ABSOLUTE-CONFIGURATION CONSTITUENTS TRYPTOPHAN PROLINE Melicopteline A-E, Unusual Cyclopeptide Alkaloids with Antiviral Activity against Influenza A Virus from Melicope pteleifolia Article 10.1021/acs.joc.0c02137 1 JOURNAL OF ORGANIC CHEMISTRY, v.86, no.2, pp.1437 - 1447 JOURNAL OF ORGANIC CHEMISTRY 86 2 1437 1447 scie scopus 000643595200010 2-s2.0-85099109145 Chemistry, Organic Chemistry Article ABSOLUTE-CONFIGURATION CONSTITUENTS TRYPTOPHAN PROLINE