Project description:Davidia involucrata Baill. is a kind of tertiary paleotropical plant floristic relic species unique to China. This rare plant is disappearing due to poor adaptability and serious poaching. Davidia involucrata has been listed as a national first-level protected wild plant, a unique genus plant unique to China, a relic plant, and a well-known ornamental plant in the world. It is a national-level protected plant. In this study, the complete chloroplast genome sequence of D. involucrata was characterized from Illumina pair-end sequencing. The chloroplast genome of D. involucrata was 158,118 bp in length, containing a large single-copy (LSC) region of 87,329 bp, a small single-copy (SSC) region of 18,869 bp, and two inverted repeat (IR) regions of 25,960 bp. The overall GC content is 37.80%, while the corresponding values of the LSC, SSC, and IR regions are 36.0%, 31.6%, and 43.1%, respectively. The genome contains 132 complete genes, including 86 protein-coding genes, 38 tRNA genes, and eight rRNA genes. Phylogenetic analysis based on complete chloroplast genomes showed that D. involucrata and Camptotheca acuminate clustered together as sisters to other related species.
Project description:Three new ursane triterpenes, 3α,19α-dihydroxy-2-nor-urs-12-en-23,28-dioic acid-23-methyl ester (1), 19α,23-dihydroxy-3-oxo-2-nor-urs-12-en-28-oic acid (2), and 2,3-seco-3-methoxy-3,19α,23-trihydroxy-urs-12-en-2-al-28-oic acid (3), were isolated from the MeOH extract of the branch barks of Davidia involucrata, together with six known compounds. Their structures were elucidated by means of various spectroscopic analyses. The isolated triterpenes provide important evolutionary and chemotaxonomic knowledge about the monotypic genus Davidia. Five of the identified compounds showed moderate cytotoxicities against the cell proliferation of SGC-7901, MCF-7, and BEL-7404 with IC50 range from 7.26 to 47.41 μM.
