Hainanxylogranolides A–F: New Limonoids isolated from the seeds of Hainan mangrove plant Xylocarpus granatum.

Six new limonoids, named hainanxylogranolides A–F (1 – 6), together with nineteen known ones (7 – 25) were isolated from the seeds of a Hainan mangrove Xylocarpus granatum. The structures of the new compounds were established by extensive NMR spectroscopic data combined with the DFT and TDDFT calculated electronic circular dichroism spectra. Hainanxylogranolide A (1) is the aromatic B-ring limonoid containing a central pyridine ring and a C-17 substituted γ (21)-hydroxybutenolide moiety. Hainanxylogranolide B (2) belongs to the small group of mexicanolides containing a C 3 – O –C 8 bridge, whereas hainanxylogranolides C and D (3 and 4) are mexicanolides comprising a C 1 – O –C 8 bridge. Compounds 9 and 25 posed obvious inhibition effect on the tube formation of HUVECs. There are only about 25% tube-like structures were observed at the concentration of 40.0 μM of compound 25. The antiviral activities of the isolates against herpes simplex virus-1 (HSV-1) and severe fever with thrombocytopenia syndrome virus (SFTSV) were tested in vitro. Compound 23 exhibited moderate anti-SFTSV activity with the IC 50 value of 29.58 ± 0.73 μM. This is the first report of anti-angiogenic effect and anti-SFTSV activity of limonoids from the genus Xylocarpus. Hainanxylogranolides A–F: New Limonoids isolated from the seeds of Hainan mangrove plant Xylocarpus granatum. Wan-Shan Li, Xue-Ping Lei, Xin-Tong Yan, Yu-Yue Qin, Guang-Ying Chen, Song Li, and Zhong-Ping Jiang. [Display omitted] • Six new limonoids, named hainanxylogranolides A–F (1 – 6), together with nineteen known ones (7 – 25) were isolated from the seeds of Hainan Xylocarpus granatum. • Hainanxylogranolide A (1) is an unusual limonoid containing a central pyridine ring and a C-17 substituted γ (21)-hydroxybutenolide moiety. To data, only seven pyridine-containing limonoids have been reported. • C ompounds 9 and 25 posed obvious inhibition effect on the tube formation of HUVECs. • C ompound 23 exhibited moderate anti-SFTSV activity with the IC 50 value of 29.58 ± 0.73 μM. • This is the first report of anti-angiogenic effect and anti-SFTSV activity of limonoids from the genus Xylocarpus. [ABSTRACT FROM AUTHOR]