Seven new compounds, including a eupodienone-type lignan (1), a dibenzocyclooctadiene-type lignan (2), three tetrahydrofuran-type lignans (3–5), and two 1-phenylbutyl benzoates (6, 7), together with six known compounds, were isolated from the mature carpels of Manglietiastrum sinicum. The structures of new compounds 1–7 were defined by spectroscopic techniques, and the absolute configuration of manglisin A (1) was determined by X-ray crystallography. Compounds 1–4 exhibited moderate antimicrobial activities (MIC values: 0.016–0.14 μM) against Staphylococcus aureus, MRSA 82#, MRSA 92#, MRSA 98#, and MRSA 331#. Compounds 2 and 3 showed weak cytotoxic activity against five human tumor cell lines.

Ten eudesmanolides (1–10) including five new ones (1–4 and 6) were isolated from the whole plant of Wedelia trilobata (L.) Hitchc., a notoriously invasive weed in South China. As main constituents of W. trilobata, eight of these eudesmanolides were tested for their antitobacco mosaic virus (TMV) activities by the conventional half-leaf and leaf-disk method along with Western blot analysis. All of the tested compounds, at 10 μg/mL, showed strong antiviral activities in the pretreated tobacco plants with inhibition rates ranging from 46.7% to 76.5%, significantly higher than that of the positive control, ningnanmycin (13.5%). Their potential of inducing systemic acquired resistance (SAR) was also evaluated, and compounds 1 and 8 showed excellent induction activities. Furthermore, it was found that different concentrations of compound 1 promoted phenylalanine ammonia-lyase (PAL) activity in tobacco plants. To our knowledge, this is the first report that eudesmanolides could induce resistance in tobacco plants against the viral pathogen TMV.

•16 daphnane-type and 15 known diterpenoids were isolated from Trigonostemon thyrsoideum.•They were various daphnane-type diterpenoids including with or without 9,12,14- or 9,13,14- or 12,13,14- orthoester moieties; oxetane ring and macrolactone moieties.•It includes with or without orthoester moieties, oxetane ring and macrolactone ones.•Five compounds showed potent anti-HIV-1 activities (EC50 = 0.015-0.001 nM; TI = 1618–17,619).Sixteen daphnane diterpenoids, trigothysoids A−P, along with 15 known ones, were isolated from the methanol extract of the twigs and leaves of Trigonostemon thyrsoideum. Their structures were established by extensive spectroscopic techniques, including 2D NMR spectroscopy and mass spectrometry. The anti-HIV-1 activity of the compounds was also evaluated in vitro, and five compounds demonstrated potent anti-HIV-1 activity, with EC50 values of 0.015–0.001 nM and TI values of 1618–17,619.Sixteen daphnane-type diterpenoids, along with 15 known ones, were isolated from Trigonostemon thyrsoideum. The anti-HIV-1 activities of the compounds were evaluated in vitro, and five of them showed potent anti-HIV-1 activities, with the EC50 values 0.015–0.001 nM and TI values 1618–17,619.

Four new limonoids, dysohainanins A–D (1–4), and two new triterpenoids, dysohainanins E and F (5 and 6), together with seven known ones were isolated from the twigs and leaves of Dysoxylum hainanense Merr. The structures of the new compounds were determined by a variety of spectroscopic methods. The cytotoxic activities of these compounds were evaluated, and the known compound ent-19-nor-4,16,18-trihydroxy-8(14)-pomaren-15-one (13) showed in vitro cytotoxicity against HL-60, A-549, MCF-7, and SW480 cells, with IC50 values of 24.3, 28.1, 30.7, and 22.5 µM, respectively. Compounds 2 and 3 were tested their insecticidal activities using brine shrimp and both of them were inactive. Open image in new window

Eight new limonoids with four different structural frameworks, including gedunin (1, 2), havanensin (3, 4), mexicanolide (5, 6), and methyl angolensate types (7, 8), together with six known limonoids, were isolated from the leaves of Cipadessa baccifera. Compounds 2 and 5 exhibited moderate cytotoxicity against the HL-60 cell line with an IC50 value of 20 μM.