Cytotoxic effects of the biflavonoids isolated from Selaginella trichoclada on MCF-7 cells and its potential mechanism.

A new biflavonoid, (2''S)-6''-methyl-2'',3''-dihydroochnaflavone (1), along with two known ochnaflavones (2, 3), four known amentoflavones (4-7) and two known robustaflavones (8, 9) were obtained from the 70% EtOH extract of Selaginella trichoclada. The chemical structures of isolated compounds were elucidated by extensive spectroscopic analyses. Overall, compounds 1-9 displayed moderate cytotoxic effects against human breast cancer MCF-7 cell lines. Among them, compounds 2 and 8 exhibited relatively strong cytotoxic effects against MCF-7 cells with an IC50 value of 7.7 and 6.9 µΜ, respectively. The results of RNA-sequencing and KEGG functional enrichment analysis showed that 8 could induce ferroptosis in MCF-7 cells by down-regulating the expression of ferroptosis-related genes including ACSL4, NOXO1, NOXA1, ACSL5, STEAP3, LPCAT3, ATG7 and TP53. Then 8 could inhibit the expression of ACSL4 proteins through molecule docking analysis, which showed a strong interaction of - 11.89 Kcal/mol binding energy. Those results indicate that 8 could be chemotherapy agents to fight drug resistance in breast cancer by down-regulating the expression level of ACSL4 proteins via ferroptosis, which needs to be further certified in vitro.

Trichocladabiflavone A, a chalcone-flavonone type biflavonoid from Selaginella trichoclada Alsto.

A chalcone-flavonone type biflavonoid, trichocladabiflavone A (1), along with eight known biflavonoids (2-9) were isolated from the 70% EtOH extract of Selaginella trichoclada. Their structures were elucidated by extensive spectroscopic analyses. Compound 1 was the first chalcone-flavonone type biflavonoid reported in the genus Selaginella. Moreover, compound 1 exhibited moderate cytotoxicity against DU145, MCF-7 and PC3 human cancer cell lines.

Pictalignans D-F, three new neolignan derivatives from Selaginella picta.

Three new neolignan derivatives (1-3), together with three known isolariciresinol derivatives (4-6) were isolated from Selaginella picta. Their structures were elucidated by spectroscopic methods (1D/2D NMR, HRESIMS and CD). All isolated compounds were assayed on the neuroprotective activity against the injury of HT-22 cells induced by L-Glutamate in vitro. All compounds displayed potent protective effect on HT-22 cells.

Two new anthraquinone derivatives and one new triarylbenzophenone analog from Selaginella tamariscina.

Two new anthraquinone derivatives, selaginones A (1) and B (2), and one new triarylbenzophenone analog, selagibenzophenone B (3), were isolated from Selaginella tamariscina (Beauv.) Spring. Their structures were established by 1D-, 2D-NMR and HR-ESI-MS data. Compounds 1 and 2 represent the uncommon examples of aryl substituted anthraquinone derivatives. Especially, compound 2 is a unique anthranone with exceptional structural feature, in which a p-hydroxyphenyl moiety is attached to the C-10 position. Compound 3 is the second naturally occurring triarylbenzophenone and showed moderate activity against SMCC-7721 and MHCC97-H cell lines with IC50 values of 39.8, 51.5 µM respectively.

Anti-cholinesterase activities of constituents isolated from Lycopodiastrum casuarinoides.

Phytochemical investigation of the ethyl acetate extract of Lycopodiastrum casuarinoides (Spring) Holub (Lycopodiaceae) led to the isolation of nine compounds, including two new serratene triterpenoids, serrat-14-en-3α,21α-diol (1), 26-nor-8-oxo-21-one-α-onocerin (6), one new abietane diterpenoid, lycocasuarinone A (7), one new sesquiterpene acid, 7, 9-diene-1,4-epoxy-2-hydroxy-10-carboxylic acid (8) and one new chromone derivative, 5,7-dihydroxy-2-methyl esterchromone (9), together with four known serratene triterpenoids (2-5). Abietane diterpenoid (7) and sesquiterpene acid (8) from Lycopodiastrum casuarinoides are reported for the first time. Their structures and stereochemistry were unambiguously elucidated by spectroscopic analysis and comparison with known ones. All the compounds were tested for acetylcholinesterase (AChE) and butyrocholinesterase (BuChE) inhibitory activities. Bioactivity assays revealed that compound 6 exhibited the most potent AChE inhibitory effect.

Sinensiols B-G, six novel neolignans from Selaginella sinensis.

Six new neolignans, sinensiols B-G (1-6), together with three known analogues (7-9) were isolated from the whole plant of Selaginella sinensis. Their planar structures were established by comprehensive spectroscopic analyses including 1D, 2D NMR, IR and HRESIMS data. The absolute configurations of new compounds were elucidated by comparing their experimental CD spectra with known ones and using the reversed helicity rule for the 1Lb band ECD of dihydrobenzofuran neolignans. Sinensiols A-D (7, 1-3) belong to sesquilignan with a dimer of dihydrobenzo[b]furan moiety. The potential precursors of sinensiols A, B, D were also reported in this paper. In addition, all new compounds were screened for their cytotoxicity against A549 and HepG2 human cancer cell lines, and they didn't show inhibition on the growth of cancer cells.

Lycodine-type alkaloids from Lycopodiastrum casuarinoides and their cholinesterase inhibitory activities.

Four new trace alkaloids with lycodine-related structures, Lycocasuarinines A-D (1-4), together with seven known analogues (5-11), were isolated from the chloroform extract of Lycopodiastrum casuarinoides. The structures and stereochemistry of 1-4 were elucidated by spectroscopic analysis (IR, UV, MS, NMR, HRESIMS and CD) and comparison with known ones. The acetylcholinesterase (AChE) and butyrocholinesterase (BuChE) inhibitory activities of nine isolates were evaluated. Lycocasuarinine D (4) showed the most potent AChE inhibitory effect. In addition, a plausible biogenetic pathway of compound 4 was proposed.

Neolignans and serratane triterpenoids with inhibitory effects on xanthine oxidase from Palhinhaea cernua.

Three new neolignans, lycocernuasides B-D (1-3), three new serratane triterpenoids, lycernuic ketones D (8) and E (9), and lycernuic A (10), together with six known compounds, were isolated from the 75% aqueous EtOH extract of Palhinhaea cernua. Their structures and absolute configurations were established primarily by NMR, HRESIMS and circular dichroism (CD). All compounds were evaluated the inhibitory activities of xanthine oxidase. Compounds 1-3 displayed moderate inhibitory effects on xanthine oxidase with IC50 values of 30.36µM, 42.65µM and 35.33µM, respectively.

Two new compounds from the green peel of Juglans mandshurica.

A new cyclic diarylheptanoid (1) and a new flavone glucoside (2), along with seven known compounds, were isolated from the green peel of Juglans mandshurica. Their structures were elucidated based on extensive spectroscopic analyses. Moreover, the cytotoxicity against NCI-H460, A549, and K562 cancer cells of compounds 1-6 was evaluated. The results showed that compound 3 exhibited moderate inhibitory potency against the growth of three cell lines.

New isoindolinones from the fruiting bodies of Hericium erinaceum.

Hericium erinaceus is a well-known medicinal and edible mushroom, which is considered as a potential source to obtain antitumor candidates. In this work, five new isoindolinones, named erinaceolactams A-E (1-5), along with five known compounds (6-10), were isolated from 70% ethanol extract of the fruiting bodies of H. erinaceus. The structures of new compounds were validated by HRESIMS and 1D, 2D NMR. It's worth mentioning that there are two pairs of isomers included in the new compounds. Moreover, their cytotoxicity against metastatic human hepatocellular carcinoma cell lines SMMC-7221 and MHCC-97H were evaluated. The results showed that compounds 6 and 7 exhibited promising inhibitory potency against the growth of two cell lines.

[Daviditin B from Swertia davidi Franch].

AIM: To study the active constituents of Swertia davidi Franch. METHODS: Chemical components were isolated by column chromatography and their structures were established mainly by spectroscopic means (UV, IR, NMR, 2D-NMR, MS). RESULTS: Three substances were identified as 2,5-dimethoxyl-1, 4-dicarboxyl benzene (VIII), 1,5,8-trihydroxyl-3,4-dimethoxyl xanthone (IX) and 1,8-dihydroxyl-3-(3'-hydroxyl-butoxy) xanthone (X). CONCLUSION: Compounds VIII and IX were isolated from Swertia davidi Franch, for the first time, whereas compound X is a new xanthone, named daviditin B with antioxygenated activity in vitro.

[Studies of the chemical constituents of Swertia davida Franch].

AIM: To study the active constituents of Swertia davidi Franch.. METHODS: Chromatography was used to isolate and purify the chemical components, their structures were identified by spectral analysis. RESULTS: Three compounds were identified as 1,7-dihydroxy-3,8-dimethoxyxanthone (gentiacaulein) (V), 1,8-dihydroxy-3,7-dimethoxyxanthone (methylswertianin) (VI) and 1,8-dihydroxy-3,4,7-trimethoxyxanthone (VII). CONCLUSION: Compound VII is a novel xanthone, named daviditin A, the others were isolated from Swertia davidi Franch. for the first time.