Bioassay-guided fractionation of the ethanolic extract of the stem bark of Albizia julibrissin led to the isolation of ten new oleanane-type triterpenoid saponins, julibrosides J37–J46 (1–10), along with six known analogues (11–16). In addition, 11 prosapogenins (17–27) were prepared by mild or strong alkaline hydrolysis of the total saponin. The structures of 1 − 27 were determined by spectroscopic and chemical means, and their cytotoxicities against four human cancer cell lines, BGC-823, A549, HCT-116, and HepG2 were evaluated. Compounds 5–16 exhibited significant inhibitory activity with IC50 values ranging from 2.59 to 9.30 μM, and 8 turned out to be the most active compound with all IC50 values < 5 μM. A preliminary structure-activity relationship of these saponins clearly indicated that the outer monoterpenoid moiety (MT′) is a crucial substituent for cytotoxicity, and the linkage sites of the MT′ unit greatly influenced the activity. It could also be inferred that the existence of 16-OH of the aglycone almost has no effect on cytotoxicity and the N-acetyl-glucosamine moiety at C-3 seems to enhance activity.Download high-res image (175KB)Download full-size image

Three new sesquiterpene glycosides (1–3), three new glycerol glycosides (4–6), two new alkaloids (7–8), together with seven known compounds (9–15) all of which were isolated from the genus Pilea for the first time, were isolated from the whole plants of Pilea cavaleriei Levl subsp. cavaleriei. Their structures were determined by extensive spectroscopic techniques and chemical methods. The cytotoxic activity of the isolated compounds was evaluated against four cancer cell lines, and none of the tested compounds caused a significant reduction of the cell number.Download high-res image (120KB)Download full-size image

•The metabolites of 7 licorice compounds were characterized by LC/MS.•The saponin could lose gluA or form a methyl ester at the sugar chain.•The phenolic compounds mainly undertake phase II metabolism.•Isoprenylated phenolics could undertake hydroxylation reaction.•One new metabolite was obtained and identified by NMR.Licorice (Glycyrrhiza uralensis Fisch.) is one of the most popular herbal medicines worldwide. This study aims to identify the metabolites of seven representative bioactive licorice compounds in rats. These compounds include 22β-acetoxyl glycyrrhizin (1), licoflavonol (2), licoricidin (3), licoisoflavanone (4), isoglycycoumarin (5), semilicoisoflavone B (6), and 3-methoxy-9-hydroxy-pterocarpan (7). After oral administration of 250 mg/kg of 1 or 40 mg/kg of 2–7 to rats, a total of 16, 43 and 31 metabolites were detected in the plasma, urine and fecal samples, respectively. The metabolites were characterized by HPLC/DAD/ESI–MSn and LC/IT-TOF-MS analyses. Particularly, two metabolites of 1 were unambiguously identified by comparing with reference standards, and 22β-acetoxyl glycyrrhizin-6″-methyl ester (1-M2) is a new compound. Compound 1 could be readily hydrolyzed to eliminate the glucuronic acid residue. The phenolic compounds (4–7) mainly undertook phase II metabolism (glucuronidation or sulfation). Most phenolic compounds with an isoprenyl group (chain or cyclized, 2–5) could also undertake hydroxylation reaction. This is the first study on in vivo metabolism of these licorice compounds.

Two new oplopane sesquiterpenes, gmelinin A (1) and gmelinin B (2), were isolated from Artemisia gmelinii Web. ex Stechm. Their structures were established by spectroscopic techniques (mainly 1D and 2D NMR) and application of the modified Mosher method.Two new oplopane sesquiterpenes, gmelinin A (1) and gmelinin B (2), were isolated from Artemisia gmelinii Web. ex Stechm.

Carduus acanthoides is a traditional Tibetan herbal medicine for the treatment of hematemesis, hematuria, and menorrhagia. Despite its multiple biological activities, comprehensive chemical analysis of this herb has not been reported, so far. In this study, chemical constituents of C. acanthoides were analyzed by ultra-performance liquid chromatography coupled with diode array detection and time-of-flight mass spectrometry (UPLC/DAD/qTOF-MS). The methanol extract of C. acanthoides was separated on an ACQUITY HSS T3 column (1.8 μm, 150 mm × 2.1 mm) and eluted with acetonitrile–water (containing 0.1% formic acid). Constituents were identified by UV and HRMS in the negative ion mode. A total of 69 compounds were identified from C. acanthoides, including 35 flavonoids, 17 quinic acids, 7 phenolic acid glycosides, 5 phenylethanoid glycosides, 3 coumarins, and 2 phenolic acids. Among them, 31 compounds were unambiguously characterized by comparing with reference standards. Furthermore, a UPLC/UV (340 nm) method was established to simultaneously determine 3 quinic acids and 6 flavonoids, including neochlorogenic acid (9), chlorogenic acid (16), cryptochlorogenic acid (18), kaempferol 3-O-rhamnoside-7-O-glucoside (32), luteolin 7-O-glucosyl-(1→2)-glucoside (34), luteolin 7-O-glucoside (38), luteolin 7-O-6′′′-O-acetyl-glucosyl-(1→2)-glucoside (44), kaempferol 3-O-rhamnoside (55), and chrysoeriol 7-O-6′′′-O-acetyl-glucosyl-(1→2)-glucoside (56). All analytes showed good linearity (r2 ≥ 0.998) with an LOD of 0.077–0.120 μg mL−1. These nine compounds accounted for 2.1–3.5‰ of the herb.

•Phytochemistry and chemotaxonomy of Ficus tsiangii Merr. ex Corner were studied.•34 Compounds from the stems of F. tsiangii were isolated.•Chemotaxonomy of the 34 compounds was summarized in our manuscript.•The potential chemotaxonomic markers for F. tsiangii were concluded.Thirty-four compounds, including ten coumarins (1–10), thirteen flavonoids (11–23), three triterpenoid, one lignanoid (24), seven triterpenes (25–31) and three other compounds (32–34), were isolated from the stems of Ficus tsiangii Merr. ex Corner (F. tsiangii). Their structures were identified as xanthyletin (1), coumarin (2), umbelliferone (3), isoangenomalin (4), dihydroxanthyletin (5), scopoletin (6), nodakenetin (7), 6,7-dihydroxy-coumarin (8), 4'-O-β- glucopyranosyl-3'-hydroxy-nodakenetin (9), 6-carboxy-umbelliferone (10), 5,7,4'-trimethoxy- 3'-hydroxy-aurone (11), apigenin (12), naringenin (13), genistein (14), luteolin (15), prunetin (16), chrysoeriol (17), 5,6,7,-trihydroxy-4'-methoxy-flavone (18), eriodictyol (19), isocarthamidin (20), 5,7,2',4'-tetrahydroxyflavone (21), taxifolin (22), dihydro-kaempferol (23), syringeresinol (24), taraxerol (25), taraxerone (26), lupeolacetate (27), 3-acetoxy-12- oleanene-11-ketone (28), 3-acetoxy-lup-12,20(29)-diene (29), oleanic acid (30), ursolic acid (31), 3,4,5-trimethoxy phenyl-1-O-glucopyranoside (32), 8'-hydroxyabscisic acid glucoside (33) and adenosine (34). Among them, all compounds except 3, 14, 17, 25, 26, 30, 33 were isolated from the plant for the first time, and compounds 1, 4, 5, 8–11, 16, 18, 20, 23, 24, 32, 34 were firstly reported from the genus Ficus. The chemotaxonomic significance of these compounds was summarized as follows.

Carduus acanthoides is a traditional Tibetan herbal medicine for the treatment of hematemesis, hematuria, and menorrhagia. Despite its multiple biological activities, comprehensive chemical analysis of this herb has not been reported, so far. In this study, chemical constituents of C. acanthoides were analyzed by ultra-performance liquid chromatography coupled with diode array detection and time-of-flight mass spectrometry (UPLC/DAD/qTOF-MS). The methanol extract of C. acanthoides was separated on an ACQUITY HSS T3 column (1.8 μm, 150 mm × 2.1 mm) and eluted with acetonitrile–water (containing 0.1% formic acid). Constituents were identified by UV and HRMS in the negative ion mode. A total of 69 compounds were identified from C. acanthoides, including 35 flavonoids, 17 quinic acids, 7 phenolic acid glycosides, 5 phenylethanoid glycosides, 3 coumarins, and 2 phenolic acids. Among them, 31 compounds were unambiguously characterized by comparing with reference standards. Furthermore, a UPLC/UV (340 nm) method was established to simultaneously determine 3 quinic acids and 6 flavonoids, including neochlorogenic acid (9), chlorogenic acid (16), cryptochlorogenic acid (18), kaempferol 3-O-rhamnoside-7-O-glucoside (32), luteolin 7-O-glucosyl-(1→2)-glucoside (34), luteolin 7-O-glucoside (38), luteolin 7-O-6′′′-O-acetyl-glucosyl-(1→2)-glucoside (44), kaempferol 3-O-rhamnoside (55), and chrysoeriol 7-O-6′′′-O-acetyl-glucosyl-(1→2)-glucoside (56). All analytes showed good linearity (r2 ≥ 0.998) with an LOD of 0.077–0.120 μg mL−1. These nine compounds accounted for 2.1–3.5‰ of the herb.