Zhan-n Li

Xanthones from the stem bark of Garcinia bracteata with growth inhibitory effects against HL-60 cells.

Five xanthones, 1,4,5,6-tetrahydroxyxanthone (1) and bracteaxanthones III-VI (2-5) together with twenty-six known compounds (6-31), were isolated from the ethanol extract of the stem bark of Garcinia bracteata. Their structures were elucidated via spectroscopic analyses. Growth inhibitory activities of these compounds against the human leukaemic HL-60 cell line were measured in vitro. Compounds 7, 11, and 29 exhibited moderate activities with GI(50) values of 2.8, 3.4, and 3.1 μM, respectively, and a preliminary structure-activity relationship is discussed.

Peganumine A, a β-Carboline Dimer with a New Octacyclic Scaffold from Peganum harmala

Peganumine A (1), a new dimeric β-carboline alkaloid characterized by a unique 3,9-diazatetracyclo[6.5.2.0(1,9).0(3,8)]pentadec-2-one scaffold, was isolated from the seeds of Peganum harmala. The structure including the absolute configuration was determined by spectroscopic data, X-ray crystallography, ECD calculation, and CD exciton chirality approaches. Compound 1 showed moderate cytotoxic activity against MCF-7, PC-3, and HepG2 cells and selective effects on HL-60 cells with an IC50 value of 5.8 μM.

Anti-inflammatory Diterpenoids from the Roots of Euphorbia ebracteolata

Thirteen diterpenoids (1-13), including two new norditerpene lactones (1-2) and eight new rosane diterpenoids (3-10), were isolated from the roots of Euphorbia ebracteolata. The structures were determined by 1D and 2D NMR, HRESIMS, and electronic circular dichroism (ECD). The ECD-based empirical rule for α,β-unsaturated-γ-lactones was applied to determine the absolute configurations of 1 and 2. Compounds 7, 10, and 13 exhibited significant inhibition of nitric oxide production in RAW 264.7 lipopolysaccharide-induced macrophages, with IC50 values of 2.44, 2.76, and 1.02 μM, respectively.

Caryophyllene Sesquiterpenes from the Marine-Derived Fungus Ascotricha sp. ZJ-M-5 by the One Strain–Many Compounds Strategy

The marine-derived fungus Ascotricha sp. ZJ-M-5, which can produce cyclonerodiol analogues, a 3,4-seco lanostane triterpenoid, and diketopiperazines in an eutrophic medium, was subjected to a one strain-many compounds (OSMAC) analysis. It was found to produce three new caryophyllene derivatives (1-3) and the known 1,3,6-trihydroxy-8-methylxanthone (4) in an oligotrophic medium, Czapek Dox broth with or without Mg(2+). (+)-6-O-Demethylpestalotiopsin A (1) and (+)-6-O-demethylpestalotiopsin C (2), which have a five-membered hemiacetal structural moiety, showed growth inhibitory effects against HL-60 and K562 leukemia cell lines with the lowest GI50 value of 6.9 ± 0.4 μM. It can be concluded that modification of the culture media is still effective in the discovery of novel bioactive fungal secondary metabolites.

Lanostane-Type Triterpenoids from the Roots of Kadsura coccinea

Seven new lanostane-type triterpenoids, seco-coccinic acids A-F (1- 6) and coccinilactone A (7), were isolated from the roots of Kadsura coccinea. Their structures were established on the basis of spectroscopic data analysis. The absolute configuration at C-24 of compound 5 was confirmed by the modified Moshers method. The cell growth inhibitory effects of these compounds were determined in human leukemia HL-60 cells, and it was found that compounds 1, 2, 3, and 5 exhibited antiproliferative effects with GI 50 values ranging from 6.8 to 42.1 microM.

2,5-diketopiperazines from the marine-derived fungus Aspergillus fumigatus YK-7.

Five new diketopiperazines, prenylcyclotryprostatin B (1), 20‐hydroxycyclotryprostatin B (2), 9‐hydroxyfumitremorgin C (3), 6‐hydroxytryprostatin B (4), and spirogliotoxin (5), were isolated from the marine‐derived fungus Aspergillus fumigatus YK‐7, along with nine known compounds, 6–14. Their structures were elucidated by spectroscopic methods, and their antiproliferative effects on human leukemic monocyte lymphoma U937 and human prostate cancer PC‐3 cell lines were assessed in vitro. Compounds 10, 12, and 13 exhibited significant cell growth‐inhibitory activities against U937 cell line, with the IC50 values of 1.8, 0.2, and 0.5 μM, respectively.

Two Pairs of Enantiomeric Alkaloid Dimers from Macleaya cordata

Two pairs of enantiomeric alkaloid dimers, (±)-macleayins A (1) and B (2), representing a novel dimerization pattern of two different types of alkaloids via a C-C σ-bond, were isolated from the aerial parts of Macleaya cordata. The enantiomeric separation was achieved by chiral chromatography. Their structures and stereochemistry were determined by the analysis of extensive spectroscopic data, electronic circular dichroism calculation, and single-crystal X-ray diffraction data. (-)-Macleayin A exhibits modest cytotoxic activity against HL-60 cell line with the IC50 value of 3.51 μM.

Triterpenoids from Calophyllum inophyllum and their growth inhibitory effects on human leukemia HL-60 cells.

A new friedelane-type triterpene (1), along with seven known triterpenoids, was isolated from the stems and leaves of Calophyllum inophyllum Linn. Their structures were established as 3beta, 23-epoxy-friedelan-28-oic acid (1), friedelin (2), epifriedelanol (3), canophyllal (4), canophyllol (5), canophyllic acid (6), 3-oxo-friedelan-28-oic acid (7), and oleanolic acid (8) by spectroscopic methods (NMR, EI-MS). The growth inhibitory effects of these triterpenoids on human leukemia HL-60 cells were determined.

Pegaharmalines A and B, two novel β-carboline alkaloids with unprecedented carbon skeletons from Peganum harmala

Pegaharmalines A (1) and B (2), two novel β-carboline alkaloids with unprecedented carbon skeletons, were isolated from the seeds of Peganum harmala. Their structures were determined by spectroscopic methods and the absolute configuration of 1 was elucidated by CD analysis. 1 and 2 exhibited significant cytotoxicities on HL-60 cells with IC50 values of 9.4 and 13.6 μM, respectively.

Antiproliferative activity and apoptosis inducing effects of nitric oxide donating derivatives of evodiamine

The first series of nitric oxide donating derivatives of evodiamine were designed and prepared. NO releasing ability of all target derivatives was evaluated in BGC-823, Bel-7402 and L-02 cells. The cytotoxicity was evaluated against three human tumor cell lines (Bel-7402, A549 and BGC-823) and normal human liver cells L-02. The nitrate derivatives 11a and 11b only exhibited moderate activity and furoxan-based derivatives 13a-c, 14a and 14b showed promising activity. 13c showed good cytotoxic selectivity between tumor and normal liver cells and was further investigated for its apoptotic properties on human hepatocarcinoma Bel-7402 cells. The molecular mode of action revealed that 13c caused cell-cycle arrest at S phase and induced apoptosis in Bel-7402 cells through mitochondria-related caspase-dependent pathways.