{"doi":"10.17615/r1xn-4z45","title":"Songaricalarins A–E, Cytotoxic Oplopane Sesquiterpenes from Ligularia songarica","abstract":"Five new highly oxygenated oplopane sesquiterpenes, songaricalarins A–E (1–5), and two known analogues (6 and 7) were isolated from the roots and rhizomes of Ligularia songarica. Their structures and configurations were elucidated by spectroscopic methods, including 2D-NMR techniques, and the structure of 1 was confirmed by single-crystal X-ray diffraction. All compounds were evaluated for in vitro cytotoxic activity against cultured A-549, MCF-7, KB, and KBVIN cells, and 4 exhibited cytotoxicity with EC50 values of 4.9, 0.8, 3.4, and 3.2 µg/mL, respectively.","journal":"INDIGO (University of Illinois at Chicago)","year":2020,"id":117460,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9427,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":533904,"name":"Kenneth F. Bastow","orcid":null,"position":1,"is_corresponding":false},{"id":244470,"name":"Susan L. Morris‐Natschke","orcid":"0000-0003-3772-0063","position":2,"is_corresponding":false},{"id":244476,"name":"Kuo‐Hsiung Lee","orcid":"0000-0002-6562-0070","position":3,"is_corresponding":false},{"id":520775,"name":"Daofeng Chen","orcid":"0000-0003-3806-3114","position":4,"is_corresponding":false},{"id":488296,"name":"Qi Wang","orcid":"0000-0002-0134-1726","position":5,"is_corresponding":false},{"id":547982,"name":"Tzu-Hsuan Chen","orcid":null,"position":0,"is_corresponding":true}],"reference_count":0,"raw_metadata":null,"created_at":"2026-07-18T23:13:51.309289Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}