Five New Pregnane Glycosides from the Root Barks ofPeriploca sepium

Genus Periploca (Apocynaceae): A Review of Its Classification, Phytochemistry, Biological Activities and Toxicology

The genus Periploca belongs to the family Apocynaceae, which is composed of approximately ten species of plants according to incomplete statistics. Most of these plants serve as folk medicines with a long history, especially Periploca sepium and Periploca forrestii. The botanical classifications, chemical constituents, biological activities and toxicities of the genus Periploca were summarized in the literature from 1897 to early 2019. Though the botanical classification of this genus is controversial, these species are well-known to be rich sources of diverse and complex natural products-above all, cardiac steroids and C₂₁ pregnane steroids with special structures and obvious pharmacological activities. The various crude extracts and 314 isolated metabolites from this genus have attracted much attention in intensive biological studies, indicating that they are equipped with cardiotonic, anti-inflammatory, immunosuppressive, antitumor, antimicrobial, antioxidant, insecticidal and other properties. It is noteworthy that some cardiac glycosides showed hepatotoxicity and cardiotoxicity at certain doses. Therefore, in view of the medical and agricultural value of the genus Periploca, in-depth investigations of the pharmacology in vivo, the mechanisms of biological actions, and the pharmacokinetics of the active ingredients should be carried out in the future. Moreover, in order to ensure the safety of clinical medication, the potential toxicities of cardiac glycosides or other compounds should also be paid attention. This systematic review provides an important reference base for applied research on pharmaceuticals and pesticides from this genus.

C21 steroidal glycosides and oligosaccharides from the root bark of Periploca sepium

Four new C₂₁ steroidal glycosides (1-4), named perisepiumosides FI (1-4) together with six known steroidal glycosides (5-10) and four oligosaccharides (11-14), were isolated from the root bark of Periploca sepium. Their structures were characterized on the basis of 1D and 2D-NMR spectroscopic data as well as HR-ESI-MS analysis. The evaluation of inhibition activity against human A-549 and HepG2 cell lines indicated that compounds 2, 8, 10 and 13 showed different levels of cytotoxic activities with IC₅₀ values ranging from 0.61 to 7.86μM.