New phenylbutenoids and terpene glycosides from Ginkgo biloba leaves.

Our continued works on the chemical constituents of Ginkgo biloba (G. biloba) leaves has led to the isolation of two novel phenylbutenoids (1, 2), along with five previously unidentified terpene glycosides (3-7). Among them, compounds 1 and 2 represent unique (Z)-phenylbutenoids, 3-6 are megastigmane glycosides, and 7 is identified as a rare bilobanone glycoside (Fig. 1). This study marks the first reported isolation of phenylbutenoid and bilobanone glycoside from G. biloba. The chemical structures of these compounds were elucidated through extensive spectroscopic analysis, including HR-ESI-MS and various 1D and 2D NMR experiments. Furthermore, the absolute configurations of these molecules were determined using Mosher's method, ECD experiments, and Cu-Kα X-ray crystallographic analyses.

Vlasouliodes A-D, four new C30 dimeric sesquiterpenes exhibiting potential inhibition of MCF-7 cells from Vladimiria souliei.

As our ongoing interest to search bioactive dimeric sesquiterpenes from the genus Vladimiria (Asteraceae), the plant of Vladimiria souliei was studied. Based on the repetitive chromatographic fractionation, a chemical investigation on the roots of Vladimiria souliei led to the isolation and the identification of four previously undescribed sesquiterpene dimers, vlasouliodes A-D (1-4). Their chemical structures were elucidated by comprehensive analysis of spectroscopic data, including HRESIMS, 1D and 2D NMR spectroscopic data. The absolute configurations of them were unambiguously established by the experimental and calculated ECD data. In the in vitro biological activity evaluation, 1 and 3 displayed pronounced inhibitory activity against human breast adenocarcinoma cell lines (MCF-7) with IC50 values of 17.12 ± 0.42 µM and 13.12 ± 0.10 µM, respectively. Additionally, treatment with 1 and 3 induced cell apoptosis in MCF-7 cells, down-regulated the expression of Caspase-3 and up-regulated the expression of Cleaved-caspase-3.

A new bilobalide isomer and two cis-coumaroylated flavonol glycosides from Ginkgo biloba leaves.

A new bilobalide isomer (1), together with two flavonol glycosides (2, 3), have been isolated and elucidated from the extract of Ginkgo biloba leaves. Significantly, 1 was a new sesquiterpene lactone with two lactone ring groups, both 2 and 3 were two flavonol glycosides with a same cis-coumaroylated fragment. Their chemical structures were elucidated by NMR and MS spectroscopic date and the absolute configuration of 1 was specific established by Cu-Kα X-ray crystallographic analyses. However, 1-3 showed no obvious anti-platelet aggregation activity.

Lineariifolianoids M-O, three rare sesquiterpene lactone dimers inhibiting NO production from Inula lineariifolia.

Three rare squiterpene lactone dimers lineariifolianoids M-O (1-3) were isolated from Inula lineariifolia for the first time. Their structures and absolute configuration were established on the basis of by NMR and MS spectroscopic data and X-ray crystallography. Furthermore, those three compounds exhibited significant inhibitory activity against LPS-induced NO production in RAW 264.7 macrophages with IC50 values of 1.421, 1.087 and 1.243 µM, respectively.

Bilobetin induces kidney injury by influencing cGMP-mediated AQP-2 trafficking and podocyte cell cycle arrest.

BACKGROUND: Ginkgo biloba (Gb) extracts have been used as a traditional Chinese medicine. Gb contains flavonoids, which are considered to be its active ingredients and have been used in the treatment of a variety of diseases. However, few scientific research studies on the side effects of flavonoid in Gb have been reported. PURPOSE: The present study aimed to investigate the effect of bilobetin on the kidney of Sprague-Dawley (SD) rats. STUDY DESIGN AND RESULT: In this study, rats were injected with 50 mg/kg of bilobetin, a biflavone isolated from Gb, for 7 days and aristolochic acid was used as positive controls. The results showed that the body weight and urine output of the rats were dramatically decreased, and urinary protein increased after the intraperitoneal injection of bilobetin compared with the control group. Bilobetin treatment showed vacuolar degeneration in the renal tubular epithelium, glomerular atrophy by histostaining, and podocyte fusion by electron microscopy. This study further showed that bilobetin promoted the trafficking of aquaporin 2 (AQP-2) onto the plasma membrane to achieve the function of urine concentration by in vivo study in rats and in vitro study in IMCD-3 cells. The redistribution of AQP-2 is due to increased expression of cGMP in IMCD-3 cells, which in turn promoted the phosphorylation of AQP-2 at site Ser-256. The proteinuria caused by bilobetin may be attributed to podocyte cell cycle arrest at G2/M transition, which is may associated with AKT and MAPK signaling. CONCLUSIONS: The current study showed that bilobetin has some side effects on kidneys at a dose of 50 mg/kg in SD rats and provides insight into the potential detrimental effects of monomeric ingredients in Gb.

Five rare dimeric sesquiterpenes exhibiting potential neuroprotection activity from Vladimiria souliei.

Two rare C32 sesquiterpene lactone dimers, vlasouliolides J-K (1-2), together with three C30 sesquiterpene dimers, vlasoulioliones A-C (3-5), were isolated from Vladimiria souliei. Their chemical structures were elucidated by NMR and MS spectroscopic data. Among them, compounds 1, 3 and 5 were unambiguously established by Cu-Kα X-ray crystallographic analysis. Furthermore, compound 1 showed prominent neuroprotective effects against glutamate-induced neurotoxicity in PC-12 cells, with EC50 value of 2.11 ±â€¯0.35 µM. And the leakage of LDH from glutamate-induced PC-12 was significantly reduced by compound 1 at concentration of 10 µM.

Five rare C32 sesquiterpene lactone dimers with anti-inflammation activity from Vladimiria souliei.

Five rare sesquiterpene lactone dimers, vlasouliolides E-I, were isolated from Vladimiria souliei. Their chemical structures were elucidated by spectroscopic analysis. Furthermore, 2 and 4 were unambiguously confirmed by Cu-Kα X-ray crystallographic analysis. Compounds 1, 2, 4 and 5 exhibited significant anti-inflammatory activity against LPS-induced NO production in RAW 264.7 cells with IC50 values of 1.88, 4.89, 7.24 and 2.46µM, respectively. Additionally, compounds 1 and 2 were revealed with potent inhibitory activity of the phosphorylation progress of NF-κB P65.