Alopecines A-E, five chloro-containing matrine-type alkaloids with immunosuppressive activities from the seeds of Sophora alopecuroides.

Alopecines A-E (1-5), five unusual matrine-type alkaloids featuring with an additional dichlorocyclopropane (1-3) or a di/tri-chloromethyl (4/5) attached on the D ring, were isolated from the seeds of Sophora alopecuroides. Their structures and absolute configurations were elucidated by extensive spectroscopic techniques, and X-ray diffraction analyses or time-dependent density functional theory-based electronic circular dichroism (TDDFT-ECD) calculations. Alkaloid 4 exhibited potent inhibitory effects on the proliferation of ConA-induced T lymphocytes or LPS-induced B cells with IC50 value of 3.98 or 3.74 µM, respectively.

Structurally diverse polycyclic polyprenylated acylphloroglucinols with protective effect on human vein endothelial cells injured by high-glucose from Hypericum acmosepalum N. Robson.

Hyperacmotone A, a polycyclic polyprenylated acylphloroglucinol (PPAP) with an unprecedented skeleton, along with five undescribed congeners and eleven reported ones, was isolated from Hypericum acmosepalum. Hyperacmotone A possesses a unique monocyclic ring skeleton based on a cyclopent-4-ene-1,3-dione acylphloroglucinol core. Their structures were elucidated by extensive analysis of HRESIMS, NMR, biogenetic pathway, and quantum-chemical calculations. In addition, hypercohone G exhibited significant protective effects on high-glucose-injured HUVECs.

Monoterpene indole alkaloids from Melodinus cochinchinensis (Lour.) Merr.

Melodicochinines A - D (1-4), four new monoterpene indole alkaloids (MIAs), along with 21 known ones, were isolated from the stems and twigs of Melodinus cochinchinensis. Their structures were elucidated on the basis of extensive spectroscopic analysis. A ubiquitin-rhodamine 110 assay showed that 11-methyloxytabersonine had potential inhibitory effect against ubiquitin-specific protease 7 (USP7).

Structurally diverse polyprenylated acylphloroglucinols from Hypericum uralum Buch.-Ham. ex D. Don.

Uralins A - D, four undescribed polycyclic polyprenylated acylphloroglucinols (PPAPs) featuring an unprecedented fused hexacyclic architecture, a unique monocyclic tetra-seco-tetranor-b-PPAP, an oxidative b-PPAP and a rare norspiroindane-type m-PPAP, respectively, were isolated from the aerial parts of Hypericum uralum, along with ten known PPAPs. Their structures and absolute configurations were elucidated by extensive spectroscopic techniques (MS, NMR, [α]D, CD), conceivable biogenetic pathways and time-dependent density functional theory-based electronic circular dichroism (TDDFT-ECD) calculations. Biological assays showed three b-PPAPs had moderate antioxidative damage activities, while spiroindanes exhibited moderate cytotoxic effects.

Acmoxanthones A-E, New Lavandulated Xanthones from Hypericum acmosepalum N. Robson.

Acmoxanthones A-E (1-5), five new lavandulylated xanthones, were isolated from the aerial parts of Hypericum acmosepalum, together with four known xanthones. Their structures with absolute configurations were elucidated on the basis of analysis of MS, NMR and chiroptical properties. A bioassay against high glucose-induced damage on human umbilical vein endothelial cells (HUVECs) showed ananixanthone (6) and osajaxanthone (7) had potential antioxidative damage activity with EC50 values of 10.5 µg/mL and 7.6 µg/mL, respectively, while 3-hydroxy-2,4-dimethoxyxanthone (8) exhibited cytotoxic effect on the damaged cells with IC50 values of 7.1 µg/mL.

Polyprenylated acylphloroglucinols as deubiquitinating protease USP7 inhibitors from Hypericum hookerianum.

Hookerianones A - E (1-5), five new polyprenylated acylphloroglucinols (PPAPs), along with six known ones, were isolated from the aerial parts of Hypericum hookerianum. Their structures were elucidated by analyses of MS, NMR, chiroptical properties, biogenetic pathway, and/or single crystal X-ray diffraction. A ubiquitin-rhodamine 110 assay showed that furohyperforin and hypercalin C, two representative PPAPs in this plant, inhibited more than 90% USP7 at the concentration of 10 µM.

Flueggenoids A - E, new dinorditerpenoids from Flueggea virosa.

A phytochemical investigation on the twigs and leaves of Flueggea virosa (Euphorbiaceae) led to the isolation of flueggenoids A - E (1-5), five new 13-methyl-ent-podocarpanes, together with eleven known compounds (6-16). Their structures and absolute configurations were elucidated on the basis of extensive MS and NMR data analysis, and/or single-crystal X-ray diffraction, time-dependent density functional theory (TDDFT)-based electronic circular dichroism (ECD) calculations, and chemical transformation. All isolates were evaluated for anti-HCV activity, the results showed that terpenoids of F. virosa had nonnegligible contribution for the anti-HCV activity.