Jun-Mian Tian

Isolation, structure, and bioactivities of abiesadines A–Y, 25 new diterpenes from Abies georgei Orr

Twenty-five new (abiesadines A-Y, 1-25) and 29 known (26-54) diterpenes were isolated from the aerial parts of Abies georgei. Abiesadine A (1) is a novel 8,14-seco-abietane, while abiesadine B (2) is a novel 9,10-seco-abietane. The structures of the new compounds were established on the basis of spectroscopic data analysis. Manool (52) showed the strongest effect against LPS-induced NO production in RAW264.7 macrophages with the IC(50) value of 11.0microg/mL. In another anti-inflammatory assay against TNFalpha-triggered NF-kappaB activity, (12R,13R)-8,12-epoxy-14-labden-13-ol (54) exhibited the strongest effect (IC(50)=8.7microg/mL). For antitumor assays, pomiferin A (26) and 8,11,13-abietatriene-7alpha,18-diol (29) both showed the most significant activity against LOVO cells (IC(50)=9.2microg/mL). While 7-oxocallitrisic acid (46) exhibited significant cytotoxicity against QGY-7703 tumor cells (IC(50)=10.2microg/mL).

Ainsliadimer A, a new sesquiterpene lactone dimer with an unusual carbon skeleton from Ainsliaea macrocephala.

A phytochemical investigation of Ainsliaea macrocephala led to the isolation of a new dimeric sesquiterpene lactone, ainsliadimer A (1). The structure of 1 was elucidated by spectroscopic analysis, and confirmed by single crystal X-ray diffraction. Ainsliadimer A represents an unusual carbon skeleton with a cyclopentane system connecting the two monomeric sesquiterpene lactone units. This unique molecule exerted potent inhibitory activity against the production of nitric oxide in RAW264.7 stimulated by LPS.

Terpenoids from Daphne aurantiaca and their potential anti-inflammatory activity.

Phytochemical examination of the methanolic extract from the stem bark of Daphne aurantiaca led to the isolation of six new sesquiterpenoids, dauca-3,11-dien-2alpha,15-diol (1), 3-oxoguai-4-ene-11,12-diol (2), 4alpha,5alpha,8alpha,11alphaH-3-oxoguai-1(10)-en-12,8-olide-7alpha-diol (3), 4alpha,5alpha,8alpha,11betaH-3-oxoguai-1(10)-en-12,8-olide-7beta-diol (4), 4alpha,5betaH-guai-9,7(11)-dien-12,8-olide-1alpha,8alpha-diol (5), 4alpha,5alphaH-guai-9,7(11)-dien-12,8-olide-1alpha,8alpha-diol (6), and a new diterpenoid, 12-O-benzoylphorbol 13-nonanoate (7), together with 10 known terpenoids. All compounds were tested for inhibitory activity against LPS-induced NO production in RAW 264.7 macrophages. Compounds 7, 8, 9, 10, and 11 showed potent inhibitory activities against NO production with IC(50) values of 0.01, 0.01, 0.06, 0.07, and 0.03 microM, respectively.

Chemical constituents of Crinum asiaticum L. var. sinicum Baker and their cytotoxic activities.

A phytochemical investigation of the bulbs of Crinum asiaticum L. var. sinicum Baker resulted in the isolation of two new alkaloids, asiaticumines A and B (1 and 2, resp.), together with 21 known compounds, including nine alkaloids, four amides, five phenolic compounds, and three flavonoids. All 23 compounds were isolated for the first time from Crinum asiaticum L. var. sinicum Baker. Their structures were elucidated by spectroscopic methods. In addition, ten alkaloids, 1–10, were evaluated for their cytotoxic activities against human tumor cell lines A549, LOVO, HL‐60, and 6T‐CEM. Compounds 3, 4, and 7–10 selectively showed remarkable inhibition against one or more of the tested cell lines.

Incarvilleatone, a new cyclohexylethanoid dimer from Incarvillea younghusbandii and its inhibition against nitric oxide (NO) release.

Incarvilleatone (1), an unprecedented dimeric cyclohexylethanoid analog with a racemic nature, was isolated from the whole plant of Incarvillea younghusbandii. HPLC chiral separation of 1 gave two enantiomers (-)-incarvilleatone and (+)-incarvilleatone. The structure of 1 was established by spectroscopic methods and single crystal X-ray diffraction. The absolute configurations of enantiomers were determined by quantum mechanical calculation. (-)-Incarvilleatone exhibited a potent inhibitory effect against NO production in LPS-induced RAW264.7 macrophages.

Two New Spirobiflavonoids from Abies chensiensis with Moderate NO Production Inhibitory Activity

Phytochemical investigation of the aerial parts of Abies chensiensis afforded two new (compounds 2 and 3) and 27 known compounds, including the related compound larixinol ( 1). The structures of spirobiflavonoids 1- 3 were established using 1D and 2D NMR spectroscopic techniques. In addition, the structure of larixinol ( 1) was confirmed by X-ray crystallographic analysis. Compounds 1- 3 were evaluated for inhibitory activities against LPS-induced NO production in macrophages. Larixinol ( 1) showed moderate effects, with an IC(50) value of 60.0 microg/mL. In addition, it did not show any cytotoxicity on RAW 264.7 macrophages at 100 microg/mL.

Chemical constituents of Aeschynanthus bracteatus and their weak anti-inflammatory activities

Chemical examination of the EtOAc extract from the aerial parts of Aeschynanthus bracteatus led to isolation of four phenylethanol glycosides, aeschynanthosides A-D (1-4), and 55 known constituents, including 8 phenylethanoids, 23 phenols, 5 lignans, 7 flavonoids, 9 terpenoids, and 4 others. Their structures were elucidated mainly by detailed spectroscopic studies and comparison with published data. All 59 compounds were isolated for the first time from an Aeschynanthus species. The isolates were also tested for inhibitory activities against LPS-induced NO production in RAW 264.7 macrophages. Aeschynanthoside D (4) and naringenin (41), within the concentration arrange tested (50-100 microg/mL), showed very weak dose-dependent effects with the inhibition rate of 24.2%, 35.4%, 66.0%, and 9.5%, 40.1%, 65.0%, respectively, relative to positive controls.

New Sesquiterpenoids from Ainsliaea macrocephala and Their Nitric Oxide Inhibitory Activity

Investigation of the ethanol extract of the whole plant of Ainsliaea macrocephala led to the isolation of five new sesquiterpenoids, namely ainsliadimer C (1), ainsliadimer D (2), ainsliaolide B (3), ainsliatone B (4), and ainsliaolide C (5), together with seventeen known sesquiterpenes and sesquiterpene glycosides (6- 22). Their structures were elucidated by spectroscopic methods. The relative stereochemistry of ainsliadimers C (1) and D (2) were further confirmed by single crystal X-ray diffraction analysis. Total extract of A. macrocephala and compounds 1- 22 were tested for inhibitory activity against the production of nitric oxide in RAW 264.7 cells stimulated by LPS, as well as for cytotoxicity against RAW 264.7 macrophages. Of all samples tested, purified compounds 4, 7, and 12 strongly inhibited the production of nitric oxide with IC50 values of 8.78, 2.50, and 7.11 µM, and simultaneously showed low cytotoxicity against RAW 264.7 macrophages.

Antifungal Cyclic Peptides from Psammosilene tunicoides

Three new cyclic peptides, tunicyclins B-D, and a known cyclic peptide, psammosilenin B, were isolated from the root of Psammosilene tunicoides. The structures of new cyclic peptides were elucidated by extensive NMR and MS analysis. Tunicyclin B contains an unusual α,β-dehydrotryptophan (Δ(Z)-Trp) residue, previously reported from marine sponges and bacteria. Tunicyclin D showed a broad spectrum of antifungal activity against Candida albicans (SC5314), Candida albicans (Y0109), Candida tropicalis, Candida parapsilosis, and Cryptococcus neoformans (BLS108) with MIC(80) values of 4.0, 16.0, 0.25, 1.0, and 1.0 μg mL(-1), respectively.

Tunicyclin A, the First Plant Tricyclic Ring Cycloheptapeptide from Psammosilene tunicoides

A novel cycloheptapeptide, tunicyclin A, with a unique tricyclic ring cyclopeptide skeleton, was isolated from Psammosilene tunicoides. Its structure was elucidated by extensive NMR and MS analysis. Biogenetically, tunicyclin A might be derived from cyclo-(Pro(1)-Ser(2)-(gamma-keto-delta-aldehedyl-Glu(3))-Leu(4)-Val(5)-Gly(6)-Ser(7)) via two steps of nucleophilic addition.