Xiu Gao

Isopalhinine A, a Unique Pentacyclic Lycopodium Alkaloid from Palhinhaea cernua

A new pentacyclic (5/6/6/6/7) Lycopodium alkaloid named isopalhinine A (1), which possesses a sterically congested architecture built with a tricyclo[4.3.1.0(3,7)]decane (isotwistane) moiety and a 1-azabicyclo[4.3.1]decane moiety, and palhinines B (2) and C (3) were isolated from Palhinhaea cernua. The structure and absolute configuration of 1 were elucidated by a combination of NMR spectra, optical rotation calculation, and X-ray diffraction experiment. A possible biogenetic pathway was also proposed.

Triterpenoids and Steroids with Cytotoxic Activity from Emmenopterys henryi

Two new ursane-type triterpenoids, 3β,19α,23-trihydroxyurs-12-en-24-al-28-oic acid (1) and 3β,19α,24-trihydroxy-23-norurs-12-en-28-oic acid (2), two new pregnane derivatives, 3β,12β-dihydroxy-5α-pregnane-14,16-dien-20-one (9) and 12β-hydroxy-5α-pregnane-14,16-dien-3,20-dione (10), and eight known compounds were isolated from the twigs and leaves of Emmenopterys henryi. The structures of the new compounds were elucidated on the basis of extensive spectroscopic analysis, including 1D and 2D NMR experiments. Compounds 4, 11, and 12 showed cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7, and SW-480 cell lines with IC50 values in the range of 3.11-20.12 µM.

Vibsatins A and B, Two New Tetranorvibsane-Type Diterpenoids from Viburnum tinus cv. variegatus

Vibsatins A (1) and B (2), a pair of 14,15,16,17-tetranorvibsane-type diterpenoids that feature a bicyclo[4.2.1]nonane moiety formed by a new C-13/C-2 bond, were isolated from the twigs and leaves of Viburnum tinus cv. variegatus. The structures and absolute configurations were elucidated by a combination of NMR spectra, optical rotation, and X-ray diffraction experiments. A possible biogenetic pathway is also proposed. Moreover, vibsatin A (1) enhanced the neurite outgrowth of NGF-mediated PC12 cells at a concentration of 10 μM.

Huperserines A–E, Lycopodium alkaloids from Huperzia serrata

A phytochemical study on Huperzia serrata led to the isolation of four new 5-deoxyfawcettimine-related Lycopodium alkaloids, huperserines A-D (1-4), and one new lycodine-type alkaloid, huperserine E (5). Their structures were elucidated based on spectroscopic data, including 1D and 2D NMR techniques. 5-Carbonyl or 5-hydroxyl group is a typical characteristic of lycopodine- and fawcettimine-type alkaloids. This is the first report of the 5-deoxyfawcettimine type Lycopodium alkaloids. In vitro acetylcholinesterase (AChE) inhibitory activity assay showed that huperserine E exhibited moderate anti-AChE activity with an IC₅₀ value of 6.71 μM.

Further lignans from Saururus chinensis.

Three new sauchinone analogues, sauchinones B-D (1-3), together with sauchinone (4), were isolated from the aerial part of Saururus chinensis. Structures of the new compounds were determined by extensive spectroscopic data as well as X-ray analysis. Compounds 3 and 4 inhibited nitric oxide production in lipopolysaccharide stimulated RAW 264.7 cells with IC50 values of 13.0 and 14.2 µM, respectively.

Two new diterpenoids from Excoecaria acerifolia.

A new tigliane diterpenoid, acerifolin A (1), and a new isopimarane diterpenoid, acerifolin B (2), together with two known compounds, were isolated from Excoecaria acerifolia. Their structures were elucidated on the basis of their spectroscopic methods, including 1D and 2D NMR techniques. All of the compounds were evaluated for cytotoxicity against five human cancer cell lines with cisplantin as a positive control.

Polycyclic Polyprenylated Acylphloroglucinols and Cytotoxic Constituents of Hypericum androsaemum

Two new polycyclic polyprenylated acylphloroglucinols (PPAPs), androforin A and hyperandrone A (1 and 2, resp.), together with twelve known compounds, were isolated from the aerial parts of Hypericum androsaemum. Their structures were established by detailed spectral analysis. In the cytotoxic assay, 1,4‐O‐diferuloylsecoisolariciresinol (3) showed activities comparable with those of cisplatin, and acetyloleanolic acid (4) exhibited moderate inhibitory effects against HL‐60, SMMC‐7721, A‐549, MCF‐7, and SW480 cancer cell lines.

New Lycopodium alkaloids from Phlegmariurus squarrosus

Four new Lycopodium alkaloids (1–4), together with 15 known ones, were isolated from club moss Phlegmariurus squarrosus. Notably, 8α-hydroxylycojapodine A (1) was the first derivative of lycojapodine A (5) which was a novel C16N-type Lycopodium alkaloid with an unprecedented 6/6/6/7 tetracyclic ring system. Their structures were elucidated based on the spectroscopic data, including 1D and 2D NMR techniques.

Sauruchinenols A and B, unprecedented monocyclic diterpenes with new carbon skeleton from the aerial parts of Saururus chinensis

Sauruchinenols A (1) and B (2), two novel monocyclic diterpenes with unique carbon skeleton, as well as two new structurally related diterpenes, sauruchinenols C (3) and D (4), were isolated from the aerial part of Saururus chinensis. Their structures were elucidated based on the analysis of spectroscopic data. A hypothetical biogenetic pathway for sauruchinenols A and B was proposed.

Nor-lupane triterpenoid and guaiane sesquiterpenoids from Schefflera venulosa

A novel nor-lupane triterpenoid, 3-oxo-29α-hydroxy-17β,20-epoxy-28-norlupane (1), and two new guaiane sesquiterpenoids, schvenols A-B (2-3), has been isolated from leaves of Schefflera venulosa. Structures of the new compounds were elucidated on the basis of their spectroscopic methods, including 1D and 2D NMR techniques. And the structure of 1 was further confirmed by the X-ray diffraction analysis. None of the compounds showed inhibitory effects on NO release in LPS-stimulated RAW 264.7 macrophage cell line.