Absolute Configuration of Periplosides C and F and Isolation of Minor Spiro-orthoester Group-Containing Pregnane-type Steroidal Glycosides from Periploca sepium and Their T-Lymphocyte Proliferation Inhibitory Activities

  • J Nat Prod. 2017 Apr 28;80(4):1102-1109. doi: 10.1021/acs.jnatprod.7b00017.
Luo-Yi Wang  1 ,  Jun-Jun Qin  1  2 ,  Zhen-Hua Chen  1 ,  Yu Zhou  3 ,  Wei Tang  3 ,  Jian-Ping Zuo  3 ,  Wei-Min Zhao  1
Affiliations
  • 1. Department of Natural Product Chemistry, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, People's Republic of China.
  • 2. University of Chinese Academy of Sciences , No. 19A Yuquan Road, Beijing 100049, People's Republic of China.
  • 3. State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, People's Republic of China.
PMID: 28294615 DOI: 10.1021/acs.jnatprod.7b00017
Abstract

Further phytochemical investigation of the root bark of Periploca sepium afforded nine new spiro-orthoester group-containing pregnane-type glycosides termed periplosides O-V and 3-O-formyl-periploside A. The structures of these glycosides along with the absolute configuration of the unique seven-membered formyl acetal-bridged spiro-orthoester function and the 4,6-dideoxy-3-O-methyl-Δ3-2-hexosulosyl moiety were elucidated on the basis of spectroscopic data interpretation and chemical transformation. The absolute configurations of the major compounds periplosides C and F were established by single-crystal X-ray diffraction analysis. The isolated compounds were evaluated for their inhibitory activities against the proliferation of T-lymphocytes. As a result, periploside C, the most abundant glycoside containing a spiro-orthoester moiety found in the plant, exhibited the most favorite selective index value (SI = 82.5). The length and constitution of the saccharide chain in the periplosides were found to influence the inhibitory activity and the SI value.