Chung-Hsiung Chen

Secoiridoid glycosides from Jasminum multiflorum

Abstract In addition to 10-hydroxyoleuropein and 10-hydroxyligustroside, three new secoiridoid glycosides, multifloroside, multiroside, and 10-hydroxyoleoside-11-methyl ester have been isolated from the water soluble fraction of Jasminum multiflorum. Their structures were established by spectroscopic analyses and chemical correlations. 10-Hydroxyoleuropein and multifloroside were found to possess coronary dilating and cardiotropic activities.

Anti-liver fibrotic lignans from the fruits of Schisandra arisanensis and Schisandra sphenanthera

Three new polyoxygenated C(18)-dibenzocyclooctadiene lignans, arisanschinins M and N (1 and 2) and schisphenin A (3), together with eight related metabolites (4-11), were isolated from the fruits of Schisandra arisanensis and Schisandra sphenanthera, respectively. The structures of 1-3 were elucidated on the basis of extensive spectroscopic and 2D NMR (HSQC, HMBC, and NOESY) analyses. The configuration of the biphenyl moiety in the octadiene ring was determined by circular dichroism (CD). Compound 1 possessed an unprecedented 3-(1-hydroxypropan-2-yl)-3-methyl-1,4-dioxo-2-one lactonide ring system attaching at C-6/C-14. Pharmacological studies revealed that compounds 3, 4, 6, 7, and 10 exhibited significant anti-hepatic fibrosis activity, while 9 and 11 showed cytotoxicity against HSC-T6 cells. The biogenetic pathway for compound 1 was also proposed.

Four New Briarane Diterpenoids from Taiwanese Gorgonian Junceella fragilis

Four new 8-hydroxybriarane diterpenoids, frajunolides P–S (1–4), together with umbraculolide A, juncenolide C, junceellonoid A and juncin R, were isolated from the acetone extract of the gorgonian Junceella fragilis, collected from the southeast coast of Taiwan. Compound 1 contains an unusual pivaloyloxy group at C-2, while 3 is a rare compound having a chlorine atom on the olefinic carbon (C-6). The structures of the isolated compounds were established by extensive spectroscopic analysis, including 1D- and 2D-NMR, as well as HRMS data. Compound 1 was further confirmed by X-ray crystallographic analysis. In the anti-inflammatory test, compounds 1 and 2 exhibited moderate inhibition on superoxide anion generation and elastase release by human neutrophils in response to formylmethionylleucyl-phenylalanine/dihydrocytochalasin B (fMLP/CB).

Cespihypotins Q−V, Verticillene Diterpenoids from Cespitularia hypotentaculata

Chemical investigation of the soft coral Cespitularia hypotentaculata resulted in the isolation of six new diterpenes, cespihypotins Q-V. The new metabolites comprised five verticillane-type diterpenes and one nor-verticillane derivative. Their structures were determined through detailed spectroscopic analyses, especially HRESIMS and 2D NMR techniques. The relative configuration was deduced by interpretation of NOESY spectra. Cespihypotin T exhibited significant cytotoxic activity against human Daoy and WiDr tumor cell lines.

Preparation of phenanthrene alkaloids via solvolysis of 2-hydroxyaporphines

Abstract Phenanthrene alkaloids was semisynthesized fromN-alkyllaurolitsines such as boldine directly from solvolysis with 1M ammonium acetate under reflux overnight. This one step reaction is easily workup and the yield is high (> 80%).

Randainins A–D, Based on Unique Diterpenoid Architectures, from Callicarpa randaiensis

Four new compounds, randainins A-D (1-4), were isolated from the leaves and twigs of Callicarpa randaiensis, which is an endemic species in Taiwan. Compounds 1 and 2 are diterpenoids with an unusual trans-7/5 ring system, whereas compounds 3 and 4 are diterpenoids possessing a trans-5/7 ring scaffold. The structures of the new compounds were established based on NMR and MS data analyses. Anti-inflammatory activities and cytotoxicity were tested and evaluated for these compounds. Compound 4 exhibited moderate inhibition of superoxide-anion generation with an IC50 value of 21.5 ± 2.5 μM.

Chemical constituents from Phoebe minutiflora II.

Two new lignans were isolated from Phoebe minutiflora, namely 8′-epiaristotetralone (1) and 8′-epiaristoligone (2), together with seven known compounds. Their structures and absolute stereochemistry were determined by spectral analysis (NMR and CD) and chemical correlation.

Bioactive xenicane diterpenoids from the Taiwanese soft coral Asterospicularia laurae.

Chemical investigation of the Taiwanese soft coral Asterospicularia laurae has led to the isolation of three new xenicane diterpenoids, named asterolaurins K–M (1–3, resp.). Their chemical structures were determined through extensive spectroscopic analyses (1H‐ and 13C‐NMR, 1H,1H‐COSY, HMBC, and NOESY). Compound 2 exhibited cytotoxic activity against HEp‐2, Daoy, MCF‐7, and WiDr tumor cells.

Three novel triterpenoid dienolides from Phyllanthus myrtifolius

Three novel pentacyclic triterpenoid dienolides, phyllenolide A (=3β-acetoxyglutina-5(10), 6-dien-27,8α-olide; 1), phyllenolide B (=3β-(benzoyloxy)glutina-5(10),6-dien-27,8α-olide; 2), and phyllenolide C (=3β-(2-hydroxybenzoyloxy)glutina-5(10),6-dien-27,8α-olide; 3), were isolated from the aerial parts of Phyllanthus myrtifolius Moon. (Euphorbiaceae). These three compounds possess an endocyclic γ-lactone moiety across ring C and a homo-annular diene system in ring B. Their structures were established by analyses of CD, NOED, and 2D-NMR spectra.

Cespitulones A and B, Cytotoxic Diterpenoids of a New Structure Class from the Soft Coral Cespitularia taeniata

Two novel diterpenoids, cespitulones A (1) and B (2), were isolated from extracts of the soft coral Cespitularia taeniata. Both compounds possess an unprecedented bicyclo [10.3.1] ring system with C-C bond connections between C-10 and C-20, and between C-20 and C-11. Their structures were elucidated on the basis of extensive spectroscopic analyses. Compound 1 exhibited significant cytotoxicity against human medulloblastoma and colon adenocarcinoma cancer cells.