Global Natural Products Social (GNPS)-Based Molecular-Networking-Guided Isolation of Phenolic Compounds from Ginkgo biloba Fruits and the Identification of Estrogenic Phenolic Glycosides.

Ginkgo biloba L. stands as one of the oldest living tree species, exhibiting a diverse range of biological activities, including antioxidant, neuroprotective, anti-inflammatory, and cardiovascular activities. As part of our ongoing discovery of novel bioactive components from natural sources, we directed our focus toward the investigation of potential bioactive compounds from G. biloba fruit. The profiles of its chemical compounds were examined using a Global Natural Products Social (GNPS)-based molecular networking analysis. Guided by this, we successfully isolated and characterized 11 compounds from G. biloba fruit, including (E)-coniferin (1), syringin (2), 4-hydroxybenzoic acid 4-O-ß-D-glucopyranoside (3), vanillic acid 4-O-ß-D-glucopyranoside (4), syringic acid 4-O-ß-D-glucopyranoside (5), (E)-ferulic acid 4-O-ß-D-glucoside (6), (E)-sinapic acid 4-O-ß-D-glucopyranoside (7), (1'R,2'S,5'R,8'S,2'Z,4'E)-dihydrophaseic acid 3'-O-ß-D-glucopyranoside (8), eucomic acid (9), rutin (10), and laricitrin 3-rutinoside (11). The structural identification was validated through a comprehensive analysis involving nuclear magnetic resonance (NMR) spectroscopic data and LC/MS analyses. All isolated compounds were evaluated using an E-screen assay for their estrogen-like effects in MCF-7 cells. As a result, compounds 2, 3, 4, 8, and 9 promoted cell proliferation in MCF-7 cells, and these effects were mitigated by the ER antagonist, ICI 182,780. In particular, cell proliferation increased most significantly to 140.9 ± 6.5% after treatment with 100 µM of compound 2. The mechanism underlying the estrogen-like effect of syringin (2) was evaluated using a Western blot analysis to determine the expression of estrogen receptor α (ERα). We found that syringin (2) induced an increase in the phosphorylation of ERα. Overall, these experimental results suggest that syringin (2) can potentially aid the control of estrogenic activity during menopause.

Phytochemical Investigation of Equisetum arvense and Evaluation of Their Anti-Inflammatory Potential in TNFα/INFγ-Stimulated Keratinocytes.

Equisetum arvense L. (Equisetaceae), widely known as 'horsetail', is a perennial plant found extensively across Asia. Extracts of E. arvense have been used in traditional medicine, particularly for the treatment of inflammatory disorders. This study aimed to determine the phytochemical compounds in E. arvense ethanolic extract and their anti-inflammatory properties. Subsequently, we isolated and identified nine secondary metabolites, including kaempferol 3,7-di-O-ß-D-glucopyranoside (1), icariside B2 (2), (Z)-3-hexenyl ß-D-glucopyranoside (3), luteolin 5-O-ß-D-glucopyranoside (4), 4-O-ß-D-glucopyranosyl caffeic acid (5), clemastanin B (6), 4-O-caffeoylshikimic acid (7), (7S,8S)-threo-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-4-O-ß-D-glucopyranoside (8), and 3-O-caffeoylshikimic acid (9). The chemical structures of the isolated compounds (1-9) were elucidated using HR-ESI-MS data, NMR spectra, and ECD data. Next, the anti-inflammatory effects of the isolates were evaluated in tumor necrosis factor (TNF)α/interferon (IFN)γ-induced HaCaT, a human keratinocyte cell line. Among the isolates, compound 3 showed the highest inhibitory effect on the expression of pro-inflammatory chemokines, followed by compounds 6 and 8. Correspondingly, the preceding isolates inhibited TNFα/IFNγ-induced activation of pro-inflammatory transcription factors, signal transducer and activator of transcription 1, and nuclear factor-κB. Collectively, E. arvense could be employed for the development of prophylactic or therapeutic agents for improving dermatitis.