Chun-Lei Zhang

Iridal-type triterpenoids with neuroprotective activities from Iris tectorum.

Six novel iridal-type triterpenoids with a previously unreported 3,6-dihydro-2H-pyran moiety, named spirioiridotectals A-F (1-6), were isolated from the ethanol extract of the rhizomes of Iris tectorum. Their structures were elucidated on the basis of extensive spectroscopic analysis. Furthermore, in in vitro bioactivity assays, compounds 1, 2, and 6 exhibited neuroprotective activities against serum-deprivation-induced PC12 cell damage.

Polycycloiridals A-D, Four Iridal-Type Triterpenoids with an α-Terpineol Moiety from Iris tectorum.

Polycycloiridals A-D, four novel iridals with an unprecedented α-terpineol moiety resulting from cyclization of the homofarnesylside chain, were isolated from the ethanol extract of rhizomes of Iris tectorum. Their structures were elucidated on the basis of comprehensive spectroscopic analysis. The absolute configuration of 1 was determined by the modified Moshers method and comparison of experimental and calculated electronic circular dichroism (ECD) spectrum. A possible biosynthetic pathway was postulated.

Bioactive Iridoid Glycosides from the Whole Plants of Rehmannia chingii

Nine new iridoid glycosides, rehmachingiiosides A-I (1-9), together with 16 known analogues, were isolated from the whole plants of Rehmannia chingii. The structures of compounds 1-9 were elucidated on the basis of spectroscopic data analysis and from chemical evidence. Furthermore, in two vitro assays, compounds 5 and 10 showed an inhibitory effect on LPS-induced NO production with IC50 values of 2.5 and 7.3 μM, and compounds 4, 6, and 10-12 (when evaluated at 10 μM) exhibited evidence of hepatoprotective effects against APAP-induced HepG2 cell damage.

Ionone glycosides from the roots of Rehmannia glutinosa

Four new ionone and ionone glycosides (1–4), and a new monoterpene (5), together with 10 known analogues (6–15), were isolated from the air-dried roots of Rehmannia glutinosa. The structures of these compounds were elucidated on the basis of spectroscopic data analysis. Furthermore, in in vitro assays, compound 3 (10 μM) exhibited moderate hepatoprotective activities against d-galactosamine-induced HL-7702 cell damage.

Hepatoprotective Triterpenoids and Saponins of Schefflera kwangsiensis

Seven new triterpenoid saponins, schekwangsiensides A-G (1-7), and a new triterpenoid, schekwangsienin (8), together with nine known triterpenoids and saponins (9-17), were isolated from the aerial parts of Schefflera kwangsiensis. The structures of these compounds were elucidated on the basis of spectroscopic data analysis and chemical evidence. Furthermore, in in vitro assays, compounds 4, 8, 9, and 15 (10 µM) exhibited moderate hepatoprotective activities against D-galactosamine-induced HL-7702 cell damage.

Cytotoxic Taccalonolides and Withanolides from Tacca chantrieri

Six new taccalonolides, taccalonolides AT-AY (1-6), and two new withanolides, chantriolides D and E (7 and 8), together with ten known compounds (9-18), have been isolated from whole plants of Tacca chantrieri. The structures, including the absolute configurations of some of the compounds, were determined by spectroscopic and chemical methods. All compounds were evaluated for their in vitro cytotoxicity against five tumor cell lines. Compounds 9, 10, 13-15, and 17 exhibited cytotoxic activity, with IC50 values of 1.13-5.71 µM, while compound 7 showed selective cytotoxicity. The results indicated that taccalonolides with a six-membered lactone moiety located at C-15 and C-24 were devoid of cytotoxicity against five tumor cell lines (> 10 µM).

Polycycloiridals with a Cyclopentane Ring from Iris tectorum

Six new iridal-type triterpenoids containing an unprecedented cyclopentane ring, polycycloiridals E-J (1-6), were isolated from a large-scale re-extraction of Iris tectorum. A possible biosynthesis pathway is postulated. The known spirioiridotectal D (7) was also obtained in the current investigation, and its structure was unequivocally defined using X-ray diffraction data. Compound 7 suppressed LPS-activated NO production in the BV2 cell line with an IC50 value of 0.54 μM.

Aromatic glycosides from the whole plants of Iris japonica

Abstract Phytochemical investigation on the whole plants of Iris japonica led to the isolation of four new aromatic glycosides. Their structures including the absolute configurations were determined by spectroscopic and chemical methods as (−)-4-hydroxy-3-methoxy acetophenone 4-O-β-d-{6-O-[4-O-(7R,8S)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (1), (−)-4-hydroxy-3-methoxy acetophenone 4-O-β-d-{6-O-[4-O-(7S,8R)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (2), (−)-4-hydroxy-3-methoxy acetophenone 4-O-β-d-{6-O-[4-O-(7R,8R)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (3), (−)-4-hydroxy-3-methoxy acetophenone 4-O-β-d-{6-O-[4-O-(7S,8S)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (4), respectively. Graphical abstract

Bioactive carboxylic acids from Lysimachia clethroides

Six new carboxylic acids (1–6), together with 11 known ones (7–17), were isolated from the aerial parts of Lysimachia clethroides. Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence. Five new carboxylic acids (1 and 3–6) were evaluated for their in vitro inhibitory activity against aldose reductase.

Apocynin derivatives from Iris tectorum

Abstract Phytochemical investigation of the rhizomes of Iris tectorum resulted in the isolation and characterization of three new apocynin derivatives, apocynin-4-O-β-D-(6′-O-syringyl)glucopyranoside (1), scrophenoside C-7-ethyl ether (2, 3), together with a new naturally occurring compound but known by synthesis, apocynin-4-O-β-D-xylopyranoside (4), and five known ones (5–9). Their structures were elucidated on the basis of spectroscopic data interpretation.