AUTHOR=Shehla Nuzhat , Li Bin , Cao Liang , Zhao Jianping , Jian Yuqing , Daniyal Muhammad , Wahab Atia-tul , Khan Ikhlas A. , Liao Duan-fang , Rahman Atta-ur , Choudhary M. Iqbal , Wang Wei 

TITLE=Xuetonglactones A–F: Highly Oxidized Lanostane and Cycloartane Triterpenoids From Kadsura heteroclita Roxb. Craib.

JOURNAL=Frontiers in Chemistry

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2019.00935

DOI=10.3389/fchem.2019.00935

ISSN=2296-2646

ABSTRACT=<p>Xuetonglactones A–F (<bold>1</bold>–<bold>6</bold>), six unreported highly oxidized lanostane- and cycloartane-type triterpenoids along with 22 known scaffolds (<bold>7</bold>–<bold>28</bold>) were isolated from the stems of <italic>Kadsura heteroclita</italic> (Roxb.) Craib. Compared with previous congeners, xuetonglactone A (<bold>1</bold>), possesses an unprecedented 20,21-α-epoxide, and xuetonglactone D (<bold>4</bold>) features an unusual 19-α-hydroperoxyl moiety. The structures and the absolute configurations of the compounds were established by extensive one- and two-dimensional NMR, and electronic circular dichroism (ECD) spectroscopic analysis, with those of <bold>1</bold> and <bold>5</bold> confirmed by single-crystal X-ray diffraction technique. Compounds <bold>1</bold> and <bold>2</bold> exhibited inhibition of iNOS activity in LPS-induced macrophages with IC<sub>50</sub> values of 22.0, and 17.0 μg/mL, respectively. While compounds <bold>6</bold>, <bold>7</bold>, <bold>8</bold>, and <bold>24</bold> showed potent cytotoxic activities against human cervical cancer cell lines (HeLa) with the IC<sub>50</sub> values of 4.0, 5.8, 5.0, and 6.4 μM, and against human gastric cancer cells (BGC 823) with the IC<sub>50</sub> values of 2.0, 5.0, 2.5, and 2.0 μM, respectively. Moreover, plausible biogenetic pathways of (<bold>1</bold>–<bold>6</bold>) were also proposed.</p>