Jiangang Chen

Alkaloids from Toddalia asiatica and their cytotoxic, antimicrobial and antifungal activities.

Phytochemical investigation of the ethanol extract from the roots of Toddalia asiatica resulted in the isolation of eight new alkaloids, 8-methoxynorchelerythrine (1), 11-demethylrhoifoline B (2), 8-methoxynitidine (3), 8-acetylnorchelerythrine (4), 8,9,10,12-tetramethoxynorchelerythrine (5), isointegriamide (6), 1-demethyl dicentrinone (7), and 11-hydroxy-10-methoxy-(2,3)-methylenedioxytetrahydroprotoberberine (8), together with 10 known alkaloids. Their structures were determined on the basis of spectroscopic analyses, including 1D-NMR, 2D-NMR, and HR-ESI-MS. The isolated components were evaluated in vitro for cytotoxic activities against eight tumor cell lines, antimicrobial activities against two Gram-positive bacteria and five Gram-negative bacteria, and antifungal activities against five pathogens. Benzo[c]phenanthridine and secobenzo[c]phenantridine alkaloids exhibited significant cytotoxic, antimicrobial and antifungal properties.

Antinociceptive activity of Rhoifoline A from the ethanol extract of Zanthoxylum nitidum in mice.

AIM OF THE STUDY Antinociceptive activity of Rhoifoline A (RA), a benzophenanthridine alkaloid obtained from the ethanol extract of Zanthoxylum nitidum, was evaluated in mice using chemical and thermal models of nociception. MATERIALS AND METHODS RA was evaluated on anti-nociceptive activity in mice using chemical and thermal models of nociception. RESULTS RA administered intraperitoneally at doses of 10, 20, 40 and 80 mg/kg exhibited significant inhibitions on chemical nociception induced by intraperitoneal acetic acid and subplantar formalin, and on thermal nociception in the tail-flick test and the hot plate test. RA neither significantly impaired motor coordination in the rotarod test nor did spontaneous locomotion in the open-field test. RA did not enhance the pentobarbital sodium induced sleep time. These results indicated that the observed antinociceptive activity of RA was unrelated to sedation or motor abnormality. Core body temperature measurement showed that RA did not affect temperature during a 2-hour period. Furthermore, RA-induced antinociception in the hot plate test was insensitive to naloxone or glibenclamide but significantly antagonized by L-NAME, methylene blue and nimodipine. CONCLUSIONS Therefore, it is reasonable that the analgesic mechanism of RA possibly involved the NO-cGMP signaling pathway and L-type Ca(2+) channels.

Two new rhamnopyranosides of neolignans from Sanguisorba officinalis

Two new rhamnopyranosides of neolignans, (7S,8R)-4,9,5′,9′-tetrahydroxy-3,3′-dimethoxy-8-O-4′-neolignan-7-O-α-l-rhamnopyranoside (1) and (7S,8R)-4,9,9′-trihydroxy-3,3′,5′-trimethoxy-8-O-4′-neolignan-7-O-α-l-rhamnopyranoside (2), together with a known compound (7S,8R)-4,7,9,9′-tetrahydroxy-3,3′-dimethoxy-8-O-4′-neolignan (3), were isolated from the 80% EtOH extract of the roots of Sanguisorba officinalis. Their structures were characterized by spectroscopic analysis including 1D NMR, 2D NMR, and HR-ESI-MS, and chemical method.

Four new antioxidant phenylpropanoid glycosides from Microlepia pilosissima

Four new phenylpropanoid glycosides, 9-O-[β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl]-3,4-dimethoxy-cinnamic acid (1), 9-O-[β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl]-4-methoxycinnamic acid (2), 9-O-α-L-rhamnopyranosyl-3,4-dimethoxy-cinnamic acid (3), and 9-O-[6-Oacetyl-β-D-glucopyranosyl]-4-methoxy-cinnamic acid (4), together with three known compounds 9-O-α-L-rhamnopyranosyl-4-hydroxy-cinnamic acid (5), 9-O-β-D-glucopyranosyl-4-methoxycinnamic acid (6), and 9-O-β-D-glucopyranosyl-3,4-dimethoxy-cinnamic acid (7) were isolated from the 70% EtOH extract of the dry fronds of Microlepia pilosissima. Their chemical structures were elucidated by spectroscopic analysis. Moreover, 1 and 2 exhibited comparable scavenging activities with (±)-α-tocopherol against DPPH radicals, while compounds 3–7 displayed moderate antioxidant activities.

Chemical constituents from the ethanol extract of Viburnum ternatum

Phytochemical investigation of the 70% ethanol extract from Viburnum ternatum resulted in the isolation of three new compounds, vibsanol-9′-al (1), 4-methoxy-vibsanol (2), and 5,7-dihydroxy-4′-methoxyflavanone(8 → 3′)-5,7-dihydroxy-4′-methoxyflavone (4), together with a known compound vibsanol (3). Their structures were determined on the basis of spectroscopic analyses, including 1D and 2D NMR (COSY, HMQC, HMBC, and NOESY) and HR-ESI-MS analyses.

Three new amides from Microlepia pilosissima

Phytochemical investigation of 70% EtOH extract of the dry fronds of Microlepia pilosissima has resulted in isolation of three new amides, (7E)-N-(3′-hydroxyl-4′-methoxy)-phenylethyl-4-hydroxyl-cinnamamide (1), (7E)-N-(3′,4′,5′-trihydroxyl)-phenylethyl-4-hydroxyl-cinnamamide (2), and (7E)-N-(3′,4′,5′-trihydroxyl)-phenylethyl-4-methoxy-cinnamamide (3). Their structures were characterized by spectroscopic analysis and chemical method, including 1D NMR, 2D NMR, and HR-ESI-MS.

Amides from the Roots of Toddalia asiatica

A chemical investigation of the ethanol extract from the roots of Toddalia asiatica resulted in the isolation of three new amides, (7Z)-N-(4′-methoxyphenethyl)-3-methoxy-4-hydroxycinnamamide (1), (7Z)-N-(4′-hydroxyphenethyl)-3-methoxy-4,5-dihydroxycinnamamide (2), and (7E)-N-(4′-hydroxyphenethyl)-3,4,5-trihydroxycinnamamide (3), together with one known amide (7Z)-N-(4′-hydroxyphenethyl-3-methoxy-4-hydroxycinnamamide (4). Their structures were elucidated on the basis of extensive 1D and 2D NMR (COSY, HMQC, HMBC, and NOESY) analyses.

Cytotoxic taraxerane triterpenoids from Saussurea graminea.

Four new taraxerane triterpenoids, 1β,3β-dihydroxy-11α,12α-oxidotaraxerane (1), 28-hydroxy-11α,12α-oxidotaraxerane-3-one (2), 3β-hydroxy-11α,12α-oxidotaraxerane-28-al (3), and 3-O-acetyl-11α,12α-oxidotaraxerane-28-al (4), together with three known compounds 3β-hydroxy-11α,12α-oxidotaraxerane (5), 3β,28-dihydroxy-11α,12α-oxidotaraxerane (6), and 11α,12α-oxidotaraxerane-3-one (7), were isolated from the 70% EtOH extract of Saussurea graminea. Their structures were elucidated on the basis of extensive 1D and 2D NMR (COSY, HMQC, HMBC and NOESY) analyses. The isolated compounds were evaluated in vitro for cytotoxic properties against eight tumor cell lines (A-549, BGC-823, HCT15, HeLa, HepG2, MCF-7, SGC-7901 and SK-MEL-2).

Phenylpropanoid glycosides from Conyza japonica

Three new phenylpropanoid glycosides, named 1-O-[3-O-acetyl-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl]-3-hydroxycinnamaldehyde (1), 1-O-[2,3-O-diacetyl-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl]-3-methoxycinnamaldehyde (2), and 1-O-[3-O-acetyl-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl]-4-allyl-2-methoxyphenol (3), were isolated from the 95% EtOH extract of the dry fronds of Conyza japonica. The structures of the new compounds were elucidated by spectral methods.

Two New Compounds from Saussurea graminea

Two new compounds, 5,7-dihydroxy-4′-methoxyflavanone(3′→6)-5,7-dihydroxy-4′-methoxyflavone (1) and 1-O-[6-O-acetyl-β-D-glucopyranosyl]-3-hydroxycinnamic acid (2), were isolated from the 70% EtOH extract of Saussurea graminea. Their structures were elucidated on the basis of extensive 1D and 2D NMR (COSY, HMQC, HMBC, and NOESY) analyses.