Antidepressant alkaloids from the rhizomes of Corydalis decumbens

Two new alkaloids (1 and 2), named 1,7-dimethoxy-2'-prenyl-1',9-dihydropyrrolo-carbazole (1) and 1,7-dimethoxy-4',5'-dimethylcyclopenta-carbazole-1',3'-dione (2), along with thirteen known alkaloids (3-15) were isolated by means of silica gel, sephadex LH-20, and semi-preparative HPLC from the CHCl₃ extraction of Corydalis decumbens for the first time. Their structures were determined by NMR, MS, IR, UV, and related references. Compounds (1-15) were evaluated for their antidepressant activities by measuring inhibition of monoamine neurotransmitter reuptake in vitro. Among them, compounds 1, 2, 4, and 6 showed certain antidepressant activities.

Flavonolignan 2, 3-dehydroderivatives from Oenanthe javanica and their anti inflammatory activities

Flavonolignans, for example, silymarin and silybin, have interesting biological activities. For the first time, three new flavonolignans named oenanthenoid A-C (1-3) and nine known flavonolignan derivatives (4-12) were isolated from Oenanthe javanica. Comprehensive spectroscopic data analysis and references were used to identify all of the compounds. The anti inflammatory activities of these isolates (1-12) on RAW264.7 macrophage cells were investigated. Three new compounds (1-3) demonstrated anti inflammatory activity with IC₅₀ values ranging from 6.5 ± 0.6 to 14.7 ± 1.6 µM. Furthermore, two compounds (11 and 12) demonstrated moderate anti inflammatory activity, with IC₅₀ values ranging from 24.1 ± 1.2 to 62.5 ± 1.9 µM.

Structural elucidation and neuroprotective activities of lignans from the flower buds of Magnolia biondii Pamp

Two new lignans, 3,4-(10-methoxy-phenylallyl)-9″-((10'-isopropanol-3',4'-furan)-phenylacetyl)-8″-dioxane-7″-O-β-d-glucopyranoside (1), 3,4-benzolactone-9″-((12'-isopropanol-3',4'-furan)-phenylbutenone)-8″-dioxane-7″-O-β-d-glucopyranoside (2), and nine known lignan derivatives (3-11) were isolated from the flower buds of Magnolia biondii Pamp. for the first time. Their structures were elucidated by 1D and 2D NMR, UV, IR, and MS data, as well as by comparison with those of the references. Compounds (1-11) were evaluated for their neuroprotective activities against 6-OHDA-induced cell death in SH-SY5Y cells. As a result, compounds 1, 2, and 5 exhibited significant neuroprotective activities with IC₅₀ values in the range of 3.08-6.12 μM.

Bioactivity-guided isolation of aurone derivatives with hepatoprotective activities from the fruits of Cucumis bisexualis

Bioactivity-guided phytochemical investigation of Cucumis bisexualis has led to the isolation of three new coumarin-aurone heterodimers (1-3), along with six aurone derivatives (4-9) were isolated from C. bisexualis for the first time. Their structures were determined by their extensive spectroscopic data and comparison with the values reported in the references. All isolated compounds (1-9) were evaluated for their hepatoprotective activities on human L-O2 cells, which compared with positive control of Bifendatatum. Among them, compounds 1, 2, and 7 exhibited moderate hepatoprotective activities to promote effects on the proliferation of L-O2 cells.

Structurally Diverse Flavonolignans with Immunosuppressive and Neuroprotective Activities from the Fruits of Hippophae rhamnoides L

The fruit of Hippophae rhamnoides L. has been used for centuries in Europe and Asia as a food with high nutritional and medicinal values. In this study, a bioactivity-guided phytochemical investigation of H. rhamnoides L. has resulted in four new dimethylallylated flavonolignans (1-4), four new isopropylpentenone-flavonolignan heterodimers (5-8), two new geranylated flavonolignans (9 and 10), and 14 known flavonolignan derivatives (11-24); they were elucidated by their spectrometric and spectroscopic methods, including HR-ESI-MS, NMR, IR, and UV from the fruit of H. rhamnoides L. for the first time. Among them, compounds 2, 5, 6, 20, and 21 showed potent immunosuppressive activities with IC₅₀ values from 19.42 ± 3.91 to 48.05 ± 12.56 μM. Meanwhile, compounds 1, 4, 11, 12, and 13 showed moderate neuroprotective activities, which increased the cell survival rate from 50.30 ± 4.24% for the model group to 71.63 ± 3.04%, 70.02 ± 4.13%, 61.53 ± 5.93%, 61.08 ± 3.58%, and 65.68 ± 4.88% at 10 μM, respectively. The hypothetical biogenetic pathway and preliminary structure-activity relationship were found and discussed scientifically.

Hepatoprotective homoisoflavonoids from the fruits of Cucumis bisexualis

Cucumis bisexualis has been widely served as a beneficial wild fruit in China. Four new homoisoflavonoids (1-4), together with eight known homoisoflavonoid derivatives (5-12) were isolated from the 90% EtOH extract of C. bisexualis, using repeated open column chromatography and preparative thin-layer chromatography. They were elucidated based on the analysis of spectral data and references from the fruits of C. bisexualis for the first time. These compounds (1-12) were evaluated for their in vitro inhibitory effects against the increase of aspartate aminotransferase and alanine aminotransferase levels in H₂ O₂ -induced HepG2 cells in the range of their maximum nontoxic concentration. Among them, compounds 3, 4, 8, and 9 exhibited certain hepatoprotective activities. PRACTICAL APPLICATIONS: Cucumis bisexualis A.M. Lu ＆ G.C. Wang is an edible and medical fruit with many functional properties. A detailed study was made to identify the bioactive constituents of C. bisexualis and four new homoisoflavonoids (1-4) and eight known homoisoflavonoid derivatives (5-12) were isolated from the fruits of C. bisexualis for the first time. Compounds 3, 4, 8, and 9 exhibited certain hepatoprotective activities. This study suggests that natural compounds isolated from C. bisexualis could be used as promising hepatoprotective agents.