Four novel matrine-based alkaloids (1–4) were isolated from the seeds of Sophora alopecuroides. Compounds 1 and 2 possess unprecedented 6/6/6/4 and 6/5/6/6 ring systems, respectively, while 3 and 4 are a pair of stereoisomeric matrine–acetophenone alkaloids with an unusual skeleton. Their structures were elucidated by means of spectroscopic methods and single-crystal X-ray diffraction. Hypothetical biogenetic pathways for 1–4 are proposed, and their antiviral activities are also discussed.

•Seven previously unknown sesquiterpene lactones, elephanpene A-G, along with ten known ones were isolated from Elephantopus mollis.•Anti-inflammatory activities of the isolates were evaluated.•All tested compounds exhibited anti-inflammatory effects with IC50 values of 0.57 ± 0.17 to 59.97 ± 1.53 μM.Seven sesquiterpene lactones, 8-O-methacryloylelephanpane, 2,4-bis-O-methyl-8-O-methacryloylelephanpane, 4-O-ethyl-8-O-methacryloylelephanpane, 8-O-methacryloylisoelephanpane, 2-O-demethyltomenphantopin C, molephantin A, molephantin B, along with ten known ones, were isolated from Elephantopus mollis (Asteraceae). Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HRESIMS, 1D and 2D NMR). The isolates were evaluated for their anti-inflammatory activities on LPS-stimulated RAW 264.7 cells, and all tested compounds exhibited potent anti-inflammatory effects with IC50 values of 0.57 ± 0.17 to 14.34 ± 1.61 μM, except that compound tomenphantopin C exhibited moderate anti-inflammatory activity with IC50 values of 59.97 ± 1.53 μM.Seven sesquiterpene lactones and ten known ones were isolated from herbs of Elephantopus mollis. Selected compounds were evaluated for their anti-inflammatory activities by using the Griess assay.Download high-res image (223KB)Download full-size image

Two novel diterpenoid alkaloids, grandiflodines A and B (1 and 2), were isolated from Delphinium grandiflorum. Compound 1 represents a rare hetisine-type C20-diterpenoid alkaloid in which the bond between the atoms of N and C-17 is broken. Compound 2 features an unusual lycoctonine-type C19-diterpenoid alkaloid skeleton with the cleavage of N–C19 and C7–C17 bonds, and the construction of the N–C7 bond. Structural elucidations of the isolates were performed by spectroscopic analysis, X-ray diffraction and comparison with the literature. These compounds were tested for their antiviral and anti-inflammatory activities.

•Six unknown cycloartane triterpenoid sponins, thalisides A-F, along with four known ones were isolated from Thalictrum fortunei.•The new structures were elucidated by the spectroscopic analysis (IR, UV, HR-ESI-MS, 1D-NMR and 2D-NMR).•All isolates were evaluated for in vitro cytotoxicity against human cancer cells (A549, HepG2) and antiviral activity against influenza A virus (H1N1).Six new cycloartane triterpenoid saponins, thalisides A-F (1–6), along with four known ones (7–10), were isolated from Thalictrum fortunei. The new structures were elucidated by using spectroscopic data (NMR, IR, UV, and MS). Compounds 1–10 were examined for their in vitro cytotoxicity against two human cancer cell lines (HepG2, A549) and antiviral activity against influenza A virus (H1N1) and found to be inactive.Download high-res image (180KB)Download full-size image

Nine new labdane diterpenoids (1–9) were isolated from the aerial parts of Croton laui, along with eight known analogues (10–17). Their structures were identified on the basis of the spectral data (IR, UV, HRESIMS, 1D and 2D NMR), and the structure of 8 was confirmed by single crystal X-ray diffraction analyses. In addition, compounds 1, 4, 7, 8, and 14 showed weak anti-inflammatory activities in LPS-stimulated RAW 264.7 cells.

Six unusual matrine-type alkaloid dimers, flavesines A–F (1–6, respectively), together with three proposed biosynthetic intermediates (7–9) were isolated from the roots of Sophora flavescens. Compounds 1–5 were the first natural matrine-type alkaloid dimers, and compound 6 represented an unprecedented dimerization pattern constructed by matrine and (−)-cytisine. Their structures were elucidated by NMR, MS, single-crystal X-ray diffraction, and a chemical method. The hypothetical biogenetic pathways of 1–6 were also proposed. Compounds 1–9 exhibited inhibitory activities against hepatitis B virus.

•Six diterpenoids and eleven known ones were isolated from Croton crassifolius.•The anti-angiogenic activity of the isolated diterpenoids was evaluated.•Penduliflaworosin showed strong anti-angiogenic effect.Six diterpenoids [crassifolin J, K, L, M, N and O] along with eleven known ones were isolated from the supercritical fluid extract (SFE) of the roots of Croton crassifolius (Euphorbiaceae). Their structures were elucidated using spectroscopic methods (IR, UV, HRESIMS, 1D and 2D NMR). The structure and stereochemistry of crassifolin J was confirmed by single-crystal X-ray diffraction analysis, and the absolute configurations of crassifolin K–M were determined by CD spectra. Twenty-three diterpenoids from this plant were screened for their anti-angiogenic activity using a wild-type zebrafish in vivo model. Four of the known compounds were active, of which penduliflaworosin possessed the best activity relative to the positive control (SU5416). Further study demonstrated that penduliflaworosin could inhibit vessel formation on Tg(fli1a:EGFP)y1-type zebrafish embryos.Six diterpenoids (1–6) along with eleven known ones were isolated from the supercritical fluid extract of the roots of Croton crassifolius. All the isolates were evaluated for their anti-angiogenic activity using the zebrafish in vivo model.

Three novel sesquiterpenoid-based meroterpenoids, drychampones A–C (1–3, respectively), were isolated from Dryopteris championii. Compounds 1 and 3 possessed a novel carbon skeleton which was constructed by an 11/6/6 ring system coupled with a pyronone moiety, and 1–3 were three racemates. Their structures and absolute configurations were elucidated by NMR, MS, and computational methods. The hypothetical biosynthetic pathways of these meroterpenoids and their antibacterial activities were also discussed.

Seven new phloroglucinol derivatives (1–7) were isolated from the fruit tree Syzygium jambos together with four known triterpenoids (8–11) and two known flavones (12 and 13). According to the spectroscopic analyses (infrared, electrospray ionization mass spectrometry (ESIMS), high-resolution ESIMS, 1D and 2D nuclear magnetic resonance), the structures of compounds 1–7 were elucidated as jambone A (1), jambone B (2), jambone C (3), jambone D (4), jambone E (5), jambone F (6), and jambone G (7). All the isolates were determined for their cytotoxic activities on melanoma cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and compounds 10 and 11 showed potent activities. Moreover, compounds 1, 2, 4–7, 12, and 13 exhibited weak antioxidant activities under ferric-reducing antioxidant power and 2,2-diphenyl-1-picryhydrazyl radical-scavenging assays.

•Six new and five known phenolic compounds were isolated from Origanum vulgare.•Twenty-one phenolic compounds from Origanum vulgare were evaluated for their in vitro antioxidant and antiviral activities.•Twelve phenolic compounds were found to have potent antioxidant activity.•Some phenolic compounds were found to have weak antiviral activity.In the present study, six new phenolic compounds (1–6) along with five known ones were isolated from the ethanol extract of the whole plants of Origanum vulgare. The structures of the new compounds were identified on the basis of extensive spectroscopic analyses (UV, IR, NMR, and HRESIMS) and acid hydrolysis. Twenty-one phenolic compounds isolated from O. vulgare in our previous and present studies were evaluated for their in vitro antioxidant activity using 2,2-diphenyl-1-picryhydrazyl (DPPH) radical-scavenging and ferric-reducing antioxidant power (FRAP) assays; twelve of them including two new compounds exhibited significant antioxidant activity comparable to that of ascorbic acid. In addition, the antiviral effects against respiratory syncytial virus (RSV), Coxsackie virus B3 (CVB3) and herpes simplex virus type 1 (HSV-1) were tested by cytopathic effect (CPE) reduction assay.

•Chemical constituents of leaves of Sauropus rostratus were investigated.•Five natural carbohydrates were isolated from the leaves of Sauropus rostratus.•The absolute configurations of the three new compounds were identified.Three new hexose derivatives (1–3), together with two known ones (4,5), were isolated from the leaves of Sauropus rostratus. The structures of new compounds were elucidated on the basis of the spectroscopic methods including 1D and 2D NMR (HSQC, 1H–1H COSY, HMBC and NOESY) and HR-MS analyses. The absolute configurations of three new compounds were established by the modified Mosher’s method.

Five new phenolic glycosides, hedyotosides A–E (1–5), including a new cyanogenic glycoside (1), along with 10 known compounds (6–15) were isolated from the whole plants of Hedyotis scandens. The structures of compounds 1–5 were established by extensive spectroscopic analyses and acid hydrolysis. All the isolated compounds were evaluated for their in vitro antiviral activity against respiratory syncytial virus (RSV) with cytopathic effect (CPE) reduction assay. Compounds 6 and 15 showed anti-RSV effects with IC50 values of 20 and 25 μg/mL, respectively.