A novel monocyclic triterpenoid and a norsesquaterpenol from the aerial parts of Suaeda monoica Forssk. ex J.F. Gmel with cell proliferative potential

Suaeda monoica Forssk. ex J.F. Gmel (Chenopodiaceae), a mangrove herb, is distributed in tropical Africa, Arabian Peninsula, India, Pakistan, Palestine and Jordan. The plant parts are used to treat sore throat, hepatitis, wounds, rheumatism, paralysis, asthma, snakebites, skin disease and ulcer. Two new phytoconstituents characterized as 13,17-octahydropentalene-4,4,10,23-tetramethyl-17,21-diisopropyl-tetradecahydrocyclo-[a]-phenanthrene-(14), 20(23), 21(30)-trien-5α-ol (SMC-3) and [1,4,4-trimethyl-cyclopent-1(5)-enyl]-9,10,17,21-tetramethyl-9α-ol-16α (17α)-epoxy heptadecan-6,10-dione (SMC-4) belong to the class norsesquaterpenol and monocyclic triterpenoid, respectively, along with two known compounds 3-epi-lupeol (SMC-1) and 4-cyclopentylpyrocatechol (SMC-2) have been isolated from the ethanol extract of aerial parts of S. monoica using normal and reverse phase column as well as planar chromatography. The spectroscopic studies including 1D, 2D NMR (DEPT, COSY, HMBC and HSQC) aided by EIMS mass and IR spectra were used to establish their structures. All the four compounds were tested for cytotoxicity on cultured HepG2 cells and for cell proliferation activities. The results revealed no cytotoxicity even at highest (6.25-50 μg/ml) dose of all the four compounds. The compound SMC-1 showed prominent cell proliferative activity as compared to other SMC compounds.