title: Novel and Neuroprotective Tetranortriterpenoids from Chinese Mangrove Xylocarpus granatum Koenig.
abstract: Eight new tetranortriterpenoids (1-8) were isolated from the twigs and leaves of the Chinese mangrove plant Xylocarpus granatum, together with four related known ones (9-12). The structures of new compounds were elucidated by detailed spectroscopic analysis. The absolute configuration of 9-epixylogranatin A (1) was determined by time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD) calculations of the solution conformers. Xylogranatumin A (2) represents the first example of the 9, 10-seco limonoid with an unprecedented oxygen-bridged B ring (2,7-dioxabicyclo[2.2.1]-heptane). All the isolates were evaluated for the in vitro neuroprotective activity, both compounds 11 and 12 displayed moderate effects against H2O2-induced neurotoxicity in PC12 cells at the concentration of 10 μM, with an increase in cell viability of 12.0% and 11.6%, respectively.
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
authors.forename: Zhen-Fang
authors.initials: ZF
authors.lastname: Zhou
authors.affiliation: Department of Organic Chemistry, University of Debrecen, POB 20, 4010 Debrecen, Hungary.
authors.forename: Tibor
authors.initials: T
authors.lastname: Kurtán
authors.affiliation: Department of Organic Chemistry, University of Debrecen, POB 20, 4010 Debrecen, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Mándi
authors.affiliation: Syngenta Jealott's Hill International Research Centre, Berkshire RG42 6EY, United Kingdom.
authors.forename: Yu-Cheng
authors.initials: YC
authors.lastname: Gu
authors.affiliation: Syngenta Jealott's Hill International Research Centre, Berkshire RG42 6EY, United Kingdom.
authors.forename: Li-Gong
authors.initials: LG
authors.lastname: Yao
authors.affiliation: Institute of Biological Science, Sun Yat-Sen University, Xin Gang West Road 135, Guangzhou 510275, China.
authors.forename: Guo-Rong
authors.initials: GR
authors.lastname: Xin
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
authors.forename: Xu-Wen
authors.initials: XW
authors.lastname: Li
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
authors.forename: Yue-Wei
authors.initials: YW
authors.lastname: Guo