Chemical constituents of hybrids of Ligularia cyathiceps and L. lamarum/L. subspicata collected in China: Structures of subspicatins M, N, O1, and O2, and related compounds

Abstract

Three natural hybrids and an introgressed individual of Ligularia were evaluated based on a combination of morphology, root chemicals, and nucleotide sequences of evolutionally neutral regions to understand the chemical outcomes of hybridization and introgression. Six previously undescribed eremophilane sesquiterpenes were isolated from hybrids between L. cyathiceps and L. lamarum/L. subspicata, and benzofurans were isolated from L. subspicata for the first time. Their structures were elucidated based on spectroscopic analyses. Some compounds produced by hybrids have not been detected in either parental species, indicating that the metabolic profile was altered by hybridization and introgression.

Identification of Ligularia Herbs Using the Complete Chloroplast Genome as a Super-Barcode

“…In China, Ligularia species are mainly distributed in mountainous areas in the southwest ( Liu and Illarionova, 1989 ) and more than 30 Ligularia species have long been used in folk medicine ( Wang, 2007 ). The roots, stems, leaves, and flowers of them contain various chemical compounds, such as sesquiterpenes ( Wang, 2007 ; Shimizu et al, 2014 ; Saito et al, 2017 ) and alkaloids ( Asada et al, 1981 ; Feng, 2016 ). They are used as herbal medicines for the treatment of bronchitis, coughing, pulmonary tuberculosis, and hemoptysis.…”

“…Ligularia has been traditionally classified based on morphological structures, such as the arrangement of inflorescences, leaf shape, leaf veins, and phyllaries ( Liu and Illarionova, 1989 ). Interspecific hybridization of Ligularia species is common and their morphological variation is complicated ( Hanai et al, 2012 ; Yu et al, 2014 ; Saito et al, 2017 ), making it difficult to correctly identify species. Common DNA barcoding sequences (ITS, matK , psbA-trnH , and rbcL ) are also not ideal for identifying Ligularia species ( He and Pan, 2015 ).…”

Diversity of Furanoeremophilane Composition in Ligularia tongolensis

“…6 Sample 4 was collected at Tianchi, Shangrila County, where we collected various Ligularia hybrids, for which the chemical outcomes of hybridization were described. [7][8][9] Samples 5, 6 (4 km apart from each other), and 7 were collected in Muli County, Sichuan.…”

Chemical Composition of Intergeneric Hybrids Between Ligularia and Cremanthodium Collected in Sichuan Province of China

“…[4][5][6][7][8] Chemical characterization has revealed a variety of outcomes of hybridization. [9][10][11][12][13][14][15] In some cases, both parents contributed compounds to their offspring; in some, the chemical contribution was only from one parent; in others, hybridization appeared to have engendered compounds that were absent in their parents. 9,[12][13][14] In addition, introgression has been revealed by DNA analysis 10,12,15,16 and inferred to be behind the presence of the compounds that are detected only in some populations within a species.…”

“…NMR, JEOL ECX-400 (400 MHz for 1 H; 100 MHz for13 C) spectrometer; MS, JEOL JMS-700 MStation or CMATE II. Column chromatography (CC), silica gel (Wakosil C-200 or C-300).…”