Hai-Bo Wu

Sesquiterpene-neolignans from Manglietia hookeri

Abstract The comet assay-guided fractionation of the twigs of Manglietia hookeri resulted in the isolation of three sesquiterpene-neolignans, including a new one 5-allyl-2-(4-allyl-phenoxy)-3-[7-(1-hydroxy-1-methyl-ethyl)-1, 4a-dimethyl-decahydro-naphthalen-1-yloxy]-phenol (1), and eudesobovatol A (2) and eudesobovatol B (3), together with three lignans, obovatol (4), honokiol (5) and magnolol (6). Their structures were elucidated on the basis of spectral analysis and by comparison with related literature data. Compounds 1, 4–6 showed a protective effect on UV inductive DNA damage in mice lymphocyte cells, while compound 1 indicated the smallest Olive Tail Moment 7.34 ± 2.09 at 6 × 10−6 μM.

A new sesquiterpene from the barks of Manglietia hookeri

Abstract A new sesquiterpene manghookerins A (1) was isolated from the barks of Manglietia hookeri (Magnoliaceae) together with five known eudesmane-type sesquiterpenes. The structure of manghookerins A (1) was elucidated by physical and spectroscopic data analysis, including 1D and 2D NMR, HR-ESI-MS and X-ray diffraction. The structures of known sesquiterpenes were established by comparing their spectroscopic data with those in literatures.

A new illicinolide from leaves of Illicium micranthum Dunn

The ethyl acetate extract from leaves of Illicium micranthum Dunn exhibited radical scavenging ability on DPPH radical-scavenging assay. Further phytochemical investigation led to the isolation of a new sesquiterpenoid, illicinolide C (1), and eight known compounds (2–9). The structural elucidations of the compounds were based on spectroscopic methods and by comparison of their spectroscopic data with those reported in the references. Except compound 9, all the other compounds were isolated from I. micranthum Dunn for the first time, while compounds 1 and 2 were new to the Illiciaceae family.

6β-Hy­droxy­eremophil-7(11)-en-8β,12-olide

The title eremophilenolide, C15H22O3, is a natural compound isolated from Senecio laetus Edgew. The two cis-fused six-membered rings have chair confomations and the five-membered ring has a planar envelope conformation [maximum deviation = 0.010 (1) Å]. The β-hydroxy group participates in intermolecular O—H⋯O hydrogen bonding, forming molecular chains along the a axis.

3β-Acet­oxy-8β,10β-dihy­droxy-6β-meth­oxy­eremophil-7(11)-en-8,12-olide

The title compound, C18H26O7, is an eremophilenolide which has been isolated from the plant Ligularia duciformis for the first time. The present study confirms the atomic connectivity assigned on the basis of 1H and 13C NMR spectroscopy. The molecule contains three fused rings, two six-membered rings in chair confomations and a five-membered ring in a flattened envelope conformation. Two hydroxy groups are involved in formation of intra- and intermolecular O—H⋯O hydrogen bonds. The latter ones link molecules into chains propagating in [010].

Terpenoids from the barks of Magnolia maudiae (Dunn) Figlar

Abstract A new germacrenolide (1) and fourteen known terpenoids (2–15) were isolated from the barks of Magnolia maudiae (Dunn) Figlar (Magnoliaceae). The structure of (7αH,11βH)-2α,8α-dihydroxy-4α,5β-epoxy-germacr-1(10)-en-6α,12-olide (1) was elucidated by physical and spectroscopic data analysis, including 1D, 2D NMR and HR-ESI-MS. Lyratol F (9) was isolated from Magnolia for the first time. The structures of known compounds were established by comparing their spectroscopic data with those in literatures.

Two new eremophilenolides from the roots of Ligulariopsis shichuana and their anti-phytopathogenic fungal and antifeedant activities

Abstract Two new eremophilenolides, ligushicins A (1) and B (2), and two known compounds including β-sitosterol and ursolic acid were isolated from Ligulariopsis shichuana. The structures of new compounds were established on the basis of 1D and 2D NMR data and HRESIMS data interpretation. The absolute configuration of new compounds was assigned by ECD spectroscopy, and that of ligushicins A (1) was confirmed by X-ray diffraction analysis. The antifungal and antifeedant activities of new compounds were evaluated against four plant pathogenic fungi and third-instar larvae of Plutella xylostella, respectively. Ligushicins A (1) and B (2) exhibited potent antifungal activity against Botrytis cinerea and Fusarium oxysporum with minimum inhibitory concentration (MIC) values ranging from 50 to 100 mg/L, while they also exhibited weak antifeedant activities.

Oleanane-Type Saponins from the Roots of Ligulariopsis shichuana and Their α-Glucosidase Inhibitory Activities

Five new oleanane-type saponins, named ligushicosides A-E, and three known oleanane-type saponins were isolated from the roots of Ligulariopsis shichuana. Their structures were established by a combination of spectroscopic techniques, including 1D and 2D NMR and high resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Furthermore, all isolates were evaluated for their yeast α-glucosidase inhibitory effects and exhibited potent inhibition against α-glucosidase, while compounds 1 and 2 showed excellent inhibitory activities. The 3-O-glycoside moiety in oleanane-type saponin is important for the α-glucosidase inhibitory effects.

A New Sesquiterpenoid from the Flower Buds of Carpesium triste

A new sesquiterpenoid, 1α,3α-dihydroxy-5,7,8,11αH-eudesm-4(15)-en-8β,12-olide (1), together with three known compounds, granilin (2), β-sitosterol (3), and β-daucosterol (4), was isolated from the ethanol extract of the flower buds of Carpesium triste. Their structures were elucidated by analysis of spectroscopic data, especially13C NMR and 1D NOE spectra.

6,8-Dihy­droxy-8a-methyl-3,5-dimethyl­idenedeca­hydro­naphtho­[2,3-b]furan-2(3H)-one

The title compound, C15H20O4, is a eudesmanolide isolated from the Chinese medicinal plant Carpesium triste Maxim. The molecule contains three rings, viz. two fused six-membered rings in chair conformations and a five-membered ring in a flattened envelope conformation. In the crystal, two hydroxy groups are involved in the formation of intra- and intermolecular O—H⋯O hydrogen bonds. The H atoms in these groups are split, with site-occupation factors of 0.5. The intermolecular hydrogen bonds link molecules into chains propagating in [010].