Ya-Ching Shen

Steroids and triterpenoids of Antodia cinnamomea—A fungus parasitic on Cinnamomum micranthum

Two ergostane related steroids, zhankuic acids D and E together with three lanosta related triterpenes, 15α-acetyl-dehydrosulphurenic acid, dehydroeburicoic acid, dehydrosulphurenic acid were isolated from the fruit body of the fungus Antrodia cinnamomea. Their structures were determined by spectral analyses and comparison with known compounds.

Neolignan glucosides from Jasminum urophyllum

Abstract A novel neolignan-secoiridoid glucoside, jasurolignoside, and a new neolignan, urolignoside, have been isolated from Jasminum urophyllum . Their structures were elucidated on the basis of 2D-NMR and chemical methods.

Frajunolides E-K, briarane diterpenes from Junceella fragilis.

Chemical investigation of the gorgonian octocoral Junceella fragilis, collected in Taiwan, resulted in the isolation of seven new briarane-type diterpenes, frajunolides E-K (1-7), in addition to 14 known briaranes, praelolide, junceellin, junceellolides A-E, and K, 11a,20a-epoxy-4-deacetoxyjunceelolide D, umbraculolide A, junceellonoid A, and juncins Y, Z, and ZI, as well as ergosterol peroxide. The structures of 1-7 were determined by analysis of HRESIMS and 2D NMR spectroscopic data. Cytotoxicity and in vitro anti-inflammatory activities of compounds 1-7 were also evaluated.

Antioxidant phenylpropanoid glycosides from Smilax bracteata.

From the ethanolic extract of Smilax bracteata, six phenylpropanoid glycosides, smilasides G-L (1-6), along with four known phenylpropanoid compounds, helonioside A, helonioside B, smilaside E, and (1-p-O-coumaroyl-6-O-feruroyl)-beta-d-fructofuranosyl-alpha-d-glucopyranoside, and fourteen known phenolic compounds were isolated. Their structures were elucidated on the basis of spectroscopic analyses. Moreover, 1-6 exhibited moderate scavenging activities against DPPH radicals.

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.

Excavatolides U−Z, New Briarane Diterpenes from the GorgonianBriareum excavatum

A recent study of the EtOAc extract of the gorgonian Briareum excavatum afforded six new diterpenes of the briarane skeleton, excavatolides U-Z (1-6). The structures and relative stereochemistry of metabolites 1-6 were assigned on the basis of NMR studies and chemical methods. The structure, including the relative configuration of excavatolide U (1), was further confirmed by a single-crystal X-ray analysis. Some of the excavatolides have displayed significant cytotoxicity toward P-388 and HT-29 tumor cells.

Arisandilactone A, a new triterpenoid from the fruits of Schisandra arisanensis.

A phytochemical investigation of the fruits of Schisandra arisanensis has yielded a novel triterpenoid, arisandilactone A (1). Compound 1 has an unprecedented skeleton having a 5/5/7/5/8/5-fused hexacyclic ring system. The structure of 1 was elucidated by spectroscopic methods, especially 2D NMR techniques (COSY, HMQC, HMBC, and NOESY) and was confirmed by X-ray crystallographic analysis. A plausible biosynthetic pathway for 1 is also discussed.

Cembrane diterpenoids from the taiwanese soft coral Sarcophyton stolidotum.

Investigation of an EtOAc-soluble extract of the soft coral Sarcophyton stolidotum resulted in the isolation of seven new 14-membered carbocyclic cembranes, sarcostolides A-G (1-7), together with two known cembrane diterpenes, isosarcophytoxide and isosarcophine. The structural elucidation of these metabolites was determined on the basis of spectroscopic analyses, particularly 2D NMR techniques. Sarcostolide E (5) exhibited weak to moderate cytotoxic activity against human WiDr and Daoy tumor cell lines. A biogenetic pathway and relationship for compounds 1-7 was also proposed.

Triterpenoidal saponins from Hydrocotyle sibthorpioides

Oleanane-type triterpenoidal saponins, hydrocosisaponins A-F (1-6), along with a known saponin, hydrocotyloside VII (7), were isolated from Hydrocotyle sibthorpioides. Their structures were established on the basis of spectroscopic analyses including NMR spectroscopic techniques ((13)C, (1)H, COSY, HMQC, HMBC, TOCSY and NOESY). Biological evaluation established that saponins possessing four sugar units (three d-glucoses and one l-arabinose) (4-7) exhibited moderate cytotoxicity against KB, Daoy and WiDr human tumor cell lines.

Nortriterpene lactones from the fruits of Schisandra arisanensis.

Fractionation of an acetone extract from the fruits of Schisandra arisanensis afforded five new nortriterpene lactones, compounds 1-5, together with four known compounds, schindilactones D and E (6 and 7) and preschisanartanins A and B (8 and 9). Compound 1, a wuweiziartane-type nortriterpenoid, possesses a new type of fused ring system with a gamma-lactone ring between C-15 and C-17. Compounds 2, 6, and 7 may be categorized as schisanartane-type nortriterpenoids and compounds 3-5, 8, and 9 as preschisanartane-type nortriterpenoids. The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopic data interpretation. The structure and relative configuration of 3 were supported by single-crystal X-ray diffraction analysis. The antiviral activity against HSV-1 and inhibitory effects on superoxide anion generation and elastase release by human neutrophils in response to FMLP/CB of compounds 1-9 were evaluated.