New monoterpene phenol dimers from the fruits of Psoralea corylifolia.

Three new monoterpene phenol dimers, bisbakuchiols V-X (1-3), and two bakuchiol ethers (4 and 5), along with four known compounds (6-9) were isolated from the fruits of Psoralea corylifolia. Their structures were elucidated based on extensive spectral analysis. The absolute configurations of 1, 2, 4, and 5 were specified by quantum chemical calculations of ECD spectra.

Hypoglycemic oligostilbenes from the stems of Caragana sinica.

Six new oligostilbenes, carastilphenols A-E (1-5) and (-)-hopeachinol B (6), with three reported oligostilbenes were obtained from the stems of Caragana sinica. The structures of compounds 1-6 were determined by comprehensive spectroscopy analysis, and their absolute configurations were determined by electronic circular dichroism calculations. Thus, natural tetrastilbenes were determined as absolute configuration for the first time. Also, we did several pharmacological essays. In the antiviral tests, compounds 2, 4 and 6 showed moderate anti-coxsackie virus B3 type (CVB3) effect on Vero cells activities in vitro with IC50 values of 19.2 âˆ¼ 69.3 µM; and compounds 3 and 4 showed different levels of anti-respiratory syncytial virus (RSV) effect on Hep2 cells activities in vitro with IC50 values of 23.1 and 33.3 µM, respectively. As for hypoglycemic activity, compounds 6-9 (10 µM) showed the inhibition of α-glucosidase in vitro with IC50 values of 0.1 âˆ¼ 0.4 µM; and compound 7 showed significant inhibition (88.8%, 10 µM) of protein tyrosine phosphatase 1B (PTP1B) with IC50 value of 1.1 µM in vitro.

Nine prenylated acylphloroglucinols with potential anti-depressive and hepatoprotective activities from Hypericum scabrum.

In our screening program for new biologically active secondary metabolites, nine new polycyclic polyprenyled acylphloroglucinols, hyperscabins D-L, together with three known compounds, were obtained from the aerial parts of Hypericum scabrum. The chemical structures of 1-9 were characterized by extensive spectroscopic analyses, nuclear magnetic resonance calculation with DP4+ probability analysis, and the electronic circular dichroism spectra were calculated. Compound 1 was an unusual prenylated acylphloroglucinol decorated with a 5-oxaspiro [4,5] deca-1,9-dione skeleton. Compound 2 was a newly identified spirocyclic polyprenylated acylphloroglucinol possessing a rare 5,5-spiroketal segment. Compounds 3, 8, and 10 (10 µM) exhibited pronounced hepatoprotective activity against d-galactosamine-induced WB-F344 cell damage in vitro assays. All test compounds (1, 3, and 7-12) demonstrated potential inhibitory effects at 10 µM against noradrenalinet ([3H]-NE) reuptake in rat brain synaptosome.

Bioactive monoterpene phenol dimers from the fruits of Psoralea corylifolia L.

Nine undescribed monoterpene phenol dimers, bisbakuchiols D-L (1-9), were isolated from the fruits of Psoralea corylifolia L. Their structures were elucidated based on extensive spectral analysis. The absolute configurations of 1-9 were specified by experimental and quantum chemical calculations of ECD spectra, and that of 1 was further established by X-ray diffraction analysis using Cu Kα radiation. Bisbakuchiols (1-4) were composed of two bakuchiols, one of which was cyclized via a C-7'/ C-12' single bond to form a six-member ring, and connect to each other by C-4-O-C-13' bonds. Bisbakuchiols (7-9) had a pyran ring by linkage of C-8-O-C-12. In the enzyme assay, compounds 5 and 9 exhibited significant PTP1B inhibitory activities with IC50 values of 0.69 and 0.73 µM, and compounds 1 and 3 showed moderate PTP1B inhibitory activities. Furthermore, a molecular docking simulation of PTP1B and active compounds 5 and 9 showed that these active compounds possess low binding affinities ranging from -6.9 to -7.1 kcal/mol.

Novel oligomeric neolignans with PTP1B inhibitory activity from the bark of Magnolia officinalis var. biloba.

The barks of Magnolia officinalis var. biloba, Magnoliae cortex, have been used as traditional Chinese medicines for several centuries. In this study, phytochemical investigation of M. officinalis var. biloba bark extract afforded five pairs of novel enantiomeric oligomeric neolignans, (±)-mooligomers A-E (1-5). (±)-1 and (±)-2 were two diastereomeric pairs of enantiomers with six C6-C3 subunits, and (±)-4 was a pair of previously unreported tetrameric neolignans bearing eight C6-C3 subunits. (±)-5 is the first example of a naturally occurring trilignan featuring an eight-membered ring with a magnolol moiety. The absolute configurations of (±)-1-(±)-5 were elucidated on the basis of HRESIMS, 1D and 2D NMR spectroscopy and electronic circular dichroism (ECD) calculations. Among the compounds tested for their PTP1B inhibitory activities, (±)-2, (±)-4 and (±)-5 displayed significant PTP1B inhibitory activities with IC50 values of 0.14-2.10 µM. Furthermore, a Molecular docking simulation of PTP1B and active compounds [(±)-2, (±)-4 and (±)-5] exhibited that these active compounds possess low binding affinities ranging from - 5.9 to - 7.7 kcal/mol.

CZ-7, a new derivative of Claulansine F, ameliorates 2VO-induced vascular dementia in rats through a Nrf2-mediated antioxidant responses.

Vascular dementia (VD) results from accumulated damage in the vascular system, which is characterized by progressive impairments in memory and cognition and is second only to Alzheimer's disease (AD) in prevalence among all types of dementia. In contrast to AD, there is no FDA-approved treatment for VD owing to its multiple etiologies. In this study, we investigated whether CZ-7, a new derivative of Claulansine F (Clau F) with verified neuroprotective activity in vitro, could ameliorate the cognitive impairment of rats with permanent occlusion of bilateral common carotid arteries (2VO) and its potential mechanisms of action. The 2VO rats were orally administered CZ-7 (10, 20, 40 mg/kg) from day 27 to day 53 post-surgery. Morris water maze tests conducted at day 48-51 revealed that CZ-7 administration significantly reduced the escape latency in 2VO rats. After the rats were sacrificed on day 53, morphological studies using Nissl and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining showed that administration of CZ-7 markedly attenuated the pathological changes in CA1-CA3 area of the hippocampus, including neuronal cell loss, nuclear shrinkage, and dark staining of neurons, and significantly decreased the chronic cerebral hypoperfusion-induced cell loss. Klüver-Barrera staining study revealed that CZ-7 administration significantly improved the white matter lesions. 8-OHdG and reactive oxygen species (ROS) immunofluorescent analyses showed that CZ-7 administration significantly decreased oxidative stress in CA1-CA3 area of the hippocampus. Finally, we found that the CZ-7-improved oxidative stress might be mediated via the Nrf2 pathway, evidenced by the double immunofluorescent staining of Nrf2 and the elevation of expression levels of oxidative stress proteins HO-1 and NQO1. In conclusion, CZ-7 has therapeutic potential for VD by alleviating oxidative stress injury through Nrf2-mediated antioxidant responses.

Hepatoprotective glycosides from the rhizomes of Imperata cylindrical.

Three new C-methylated phenylpropanoid glycosides (1, 2), a new 8-4'-oxyneolignan (3), together with two known analogs (4, 5), were isolated from the rhizomes of Imperata cylindrical Beauv. var. major (Nees) C. E. Hubb. Their structures were determined by spectroscopic and chemical methods. Compounds 1, 2, and 5 (10 µM) exhibited pronounced hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell damage in vitro assays. Furthermore, their antioxidant activities against Fe2+-cysteine-induced rat liver microsomal lipid peroxidation and the effects on the secretion of TNF-α in murine peritoneal macrophages (RAW264.7) induced by lipopolysaccharides were evaluated.

New 18(4→3)-Abeo-Abietanoids from Tripterygium wilfordii.

Three 18(4→3)-abeo-abietanoids, a new natural product and two new compounds, named tripordolides A⁻C (1⁻3), were isolated from the leaves of Tripterygium wilfordii. Their structures were elucidated on the basis of their spectroscopic analysis, and the absolute configuration of compounds was confirmed by CD and X-ray crystallographic analysis using anomalous scattering of Cu Kα radiation. Compounds 1 and 3 showed moderate inhibitory activities against NO production in lipopolysaccharide-induced (LPS) RAW 264.7 macrophages in vitro.

Total synthesis and neuroprotective effect of O-methylmurrayamine A and 7-methoxymurrayacine.

O-Methylmurrayamine A (7) and 7-methoxymurrayacine (8) are natural products isolated from Murraya koenigii and Murraya siamensis, respectively. In this paper, we report the synthesis of 7 and 8 which are featured in the key step of cyclization to form carbazole intermediate 5 with mild conditions. The structures were confirmed by 1H NMR, 13C NMR, and HR-ESI-MS. In addition, compounds 7 and 8 were tested for their neuroprotective effects against H2O2-induced PC12 cell damage. The results showed that compounds 7 and 8 have neuroprotective effect.

Synthesis and Biological Evaluation of Novel Psidium Meroterpenoid Derivatives against Cisplatin-Induced Acute Kidney Injury.

Cisplatin is a widely used drug for the clinical treatment of tumors. However, nephrotoxicity limits its widespread use. A series of compounds including eight analogs (G3-G10) and 40 simplifiers (G11-G50) were synthesized based on the total synthesis of Psiguamer A and B, which were novel meroterpenoids with unusual skeletons from the leaves of Psidium guajava. Among these compounds, (d)-G8 showed the strongest protective effect on cisplatin-induced acute kidney injury (AKI) in vitro and vivo, and slightly enhanced the antitumor efficacy of cisplatin. A mechanistic study showed that (d)-G8 promoted the efflux of cisplatin via upregulating the copper transporting efflux proteins ATP7A and ATP7B. It enhanced autophagy through the activation of the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. (d)-G8 showed no acute toxicity or apparent pathological damage in the healthy mice at a single dose of 1 g/kg. This study provides a promising lead against cisplatin-induced AKI.

Chiral separation and bioactivities of six pairs of enantiomeric dilignans from Magnolia officinalis var. biloba.

Six pairs of enantiomeric dilignans, (+)/(-)-magdiligols A-F, have been isolated from an ethanolic extract of the barks of Magnolia officinalis var. biloba. Their chemical structures were elucidated by extensive spectroscopic analyses, NMR calculation with DP4+ analysis, and the electronic circular dichroism spectra calculation. (+)/(-)-1-3 possessed a dihydrobenzopyran ring, while a propyl chain of 1 was linked via ether bond. (+)/(-)-Magdiligols D and E ((+)/(-)-4 and 5) were dilignans possessing a furan ring. (+)-Magdiligol B ((+)/(-)-2), (+)/(-)-magdiligol C ((+)/(-)-3), and racemes 2, 3, and 5 showed potential hepatoprotective effects against APAP-induced HepG2 cell damage, increased the cell viability from 65.4% to 72.7, 78.7.76.6, 73.9, 77.9 and 73.2%, via decreasing the level of the live enzymes ALH and LDH consistently. (+)/(-)-Magdiligols B-D ((+)/(-)-2-4) and (+)/(-)-magdiligol F ((+)/(-)-6) exhibited significant antioxidative activity. (+)/(-)-Magdiligols B-C ((+)/(-)-2 and 3), (-)-magdiligol D ((-)-4), and (+)-magdiligol E ((+)-5) displayed significant PTP1B inhibitory activity with IC50 values 1.41-3.42 µM. (+)/(-)-Magdiligol B ((+)/(-)-2), and its raceme (2) demonstrated α-glucosidase inhibitory activity with the IC50 values 1.47, 2.88 and 1.85 µM, respectively.

Meroterpenoids with unknown skeletons from the leaves of Psidium guajava including one anti-inflammatory and anticoagulant compound: psidial F.

Four unknown meroterpenoids named as psidials D-G (1-4) together with 5 known compounds (5-9) had been obtained from the leaves of Psidium guajava. Their absolute structures were elucidated by spectral and calculated methods. Psidials DF (1-3) represented unknown carbon skeleton of the 3,5-diformylbenzyl phloroglucinol-coupled sesquiterpenoid. The possible biosynthetic pathway for 1-3 was postulated. In the bioactivity assay, psidial F (3) was found to possess anti-inflammatory and anticoagulant activities.

Neuroprotective triterpene saponins from the leaves of Panax notoginseng.

Two new triterpene saponins, namely notoginsenoside Ng5 (1) and notoginsenoside Ng6 (2) were isolated from the leaves of Panax notoginseng, along with five known ones. Their structures were determined by chemical methods, NMR and X-ray experiments. The absolute configuration of compound 3 with four sugar units was confirmed by single crystal X-ray analysis. Compounds 2-4 and 6 inhibited PC12 cell damage induced by serum deprivation, and increased cell viability from 58.7 ± 6.7% to 66.7 ± 4.5%, 76.1 ± 6.1%, 64.7 ± 5.2% and 67.2 ± 5.0% at 10 µM, respectively.

CZ-7, a new derivative of Claulansine F, promotes remyelination induced by cuprizone by enhancing myelin debris clearance.

The mechanism of demyelinating diseases is controversial, while demyelination and remyeliantion disorder is the acknowledged etiology and therapeutic target. Untill now, there is no efficient therapy for these diseases. CZ-7, a new derivative of Claulansine F, which has been reported before, were investigated its pro-remyelination effect and its associated mechanism in cuprizone (CPZ)-induced demyelination model. In this study, male C57BL/6 mice were subjected to CPZ (300 mg/kg) through intragastric gavage and were orally administered CZ-7 (20 mg/kg) meanwhile. The results of weight monitoring and behavioral testing showed that CZ-7 can significantly improve behavior dysfunction in the demyelinating mice. Luxol-fast blue (LFB) staining, myelin basic protein (MBP) immunostaining, transmission electron microscopy (TEM) and QPCR results indicated the therapeutic effect of CZ-7 on CPZ mice model. Furthermore, degraded myelin basic protein (dMBP) immunofluorescent staining and oil red O staining showed that CZ-7 contributed to the clearance of degraded myelin debris. More microglia displayed phagocytic shape assembled in corpus callosum (CC) and there was an active process of phagocytosis in microglia after CZ-7 treatment. Immunofluorescent staining and QPCR analysis revealed the M2-polarized phenotype switch of microglia in the process of myelin debris removel, which demostrated the microenvironment improvement of CZ-7. Moreover, immunofluorescent staining of NG2 and O4 demonstated that more oligodendrocyte precursor cells (OPCs) existed in CC after CZ-7 treatment. In conclusion, our results demonstrated CZ-7 has a potential therapeutic effect for MS and other demyelinating diseases through enhancing myelin debris clearance to improve the microenvironment.