Kurarinone alleviated Parkinson's disease via stabilization of epoxyeicosatrienoic acids in animal model.

Parkinson's disease (PD) is one of the most common neurodegenerative disorders and is characterized by loss of dopaminergic neurons in the substantia nigra (SN), causing bradykinesia and rest tremors. Although the molecular mechanism of PD is still not fully understood, neuroinflammation has a key role in the damage of dopaminergic neurons. Herein, we found that kurarinone, a unique natural product from Sophora flavescens, alleviated the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced behavioral deficits and dopaminergic neurotoxicity, including the losses of neurotransmitters and tyrosine hydroxylase (TH)-positive cells (SN and striatum [STR]). Furthermore, kurarinone attenuated the MPTP-mediated neuroinflammation via suppressing the activation of microglia involved in the nuclear factor kappa B signaling pathway. The proteomics result of the solvent-induced protein precipitation and thermal proteome profiling suggest that the soluble epoxide hydrolase (sEH) enzyme, which is associated with the neuroinflammation of PD, is a promising target of kurarinone. This is supported by the increase of plasma epoxyeicosatrienoic acids (sEH substrates) and the decrease of dihydroxyeicosatrienoic acids (sEH products), and the results of in vitro inhibition kinetics, surface plasmon resonance, and cocrystallization of kurarinone with sEH revealed that this natural compound is an uncompetitive inhibitor. In addition, sEH knockout (KO) attenuated the progression of PD, and sEH KO plus kurarinone did not further reduce the protection of PD in MPTP-induced PD mice. These findings suggest that kurarinone could be a potential natural candidate for the treatment of PD, possibly through sEH inhibition.

Unprecedented diterpenoid dimers with soluble epoxide hydrolase inhibitory effect from Euphorbia fischeriana.

Biseuphoids A (1) and B (2), two unprecedented ent-abietane-type diterpenoid dimers linked by monomeric blocks through C-17-C-12' and C-17-C-11', respectively, were isolated from Euphorbia fischeriana, along with their biogenesis related diterpenoid monomers, 17-hydroxyjolkinolide B (3), caudicifolin (4), and fischeriabietane C (5). Their structures were elucidated by extensive spectroscopy assisted by quantum chemical NMR and ECD calculations. The unusual dimeric skeletons are possibly derived from the adduct of diterpenoid monomers through Michael-like reactions. The novel dimers 1 and 2 exhibited inhibitory activities on soluble epoxide hydrolase (sEH) with IC50 values of 8.17 and 5.61 µM, respectively. Molecular dynamics studies illustrated that both 1 and 2 can occupy the catalytic pocket of sEH by forming stable hydrogen bonds with the key amino acid residues including Gln384, Asn378, Pro361, Ala365, Asn366, and Asn472.

Cytotoxic diterpenoid dimer containing an intricately caged core from Euphorbia fischeriana.

Bislangduoids A and B, a novel class of dimeric diterpenoids based on ent-abietanes tethered by C-17-C-15' bridge, were identified as trace components from a traditional Chinese medicine Euphorbia fischeriana (Langdu). Bislangduoid A features a highly oxidized scaffold incorporating a cage-like pentacyclic core. Their structures were elucidated by extensive spectroscopic techniques, electronic circular dichroism, and NMR calculations. The biosynthetic pathway for the dimeric skeleton and the unique caged moiety via Michael and acetal-formation reactions was proposed. Bislangduoid A showed pronounced cytotoxicity against HepG2 cells through the mitochondria-dependent apoptosis pathway.

Bisfischoids A and B, dimeric ent-abietane-type diterpenoids with anti-inflammatory potential from Euphorbia fischeriana Steud.

Two undescribed ent-abietane-type diterpenoid dimers with nonacyclic backbone formed by intermolecular [4 + 2] cycloaddition into a spirocyclic skeleton, bisfischoids A (1) and B (2), along with a known one fischdiabietane A (3), were identified from Euphorbia fischeriana Steud. Their structures were elucidated by extensive spectroscopic analysis, ECD and NMR calculation combined with DP4+ probability analysis, as well as X-ray diffraction. The anti-inflammatory potential of dimers 1-3 were examined using their inhibitory effects on soluble epoxide hydrolase (sEH), which revealed that 1 and 2 exhibited promising activities with inhibition constant (Ki) of 3.20 and 1.95 µM, respectively. Further studies of molecular docking and molecular dynamics indicated that amino acid residue Tyr343 in the catalytic cavity of sEH was the key site for their inhibitory function.

Alisma genus: Phytochemical constituents, biosynthesis, and biological activities.

The genus Alisma contains 11 species distributed worldwide, of which at least two species (A. orientale [Sam.] Juzep. and A. plantago-aquatica Linn.) have been used as common herbal medicines. Secondary metabolites obtained from the genus Alisma are considered to be the material basis for the various biological functions and medicinal applications. In this review, we mainly focused on the recent investigations of secondary metabolites from plants of the genus Alisma and their biological activities, with the highlighting on the diversity of the chemical structures, the biosynthesis of interesting secondary metabolites, the biological activities, and the relationships between structures and bioactivities.

Inula japonica ameliorated bleomycin-induced pulmonary fibrosis via inhibiting soluble epoxide hydrolase.

Pulmonary fibrosis is a progressive, irreversible, and fatal fibrotic lung disease with a high mortality and morbidity, and commonly nonresponsive to conventional therapy. Inula japonica Thunb. is a traditional Chinese medicine, known as "Xuan Fu Hua" in Chinese, and has been widely applied to relieve cough and dyspnea and eliminate retained phlegm with a long history. In this study, we aimed to evaluate the anti-fibrosis effect and action mechanism of I. japonica extract (IJE) for the treatment of bleomycin (BLM)-induced pulmonary fibrosis in mice. IJE treatment significantly restored BLM-induced alterations in body weight loss and lung function decline, decreased the collagen deposition induced by BLM in lung tissues, and inhibited fibrotic and inflammatory factors, such as α-SMA, TGF-ß1, TNF-α, IL-6, COX-2, NF-κB, and GSK3ß, in a dose-dependent manner. We found that IJE could enhance the concentration of 8,9-epoxyeicosatrienoic acid (8,9-EET) and decrease concentrations of 8,9-dihydroxyeicosatrienoic acid (8,9-DHET), 11,12-DHET, and 14,15-DHET in BLM-induced mice. Meanwhile, IJE suppressed protein and mRNA expression levels of soluble epoxide hydrolase (sEH), and significantly displayed the inhibition of sEH activity with an IC50 value of 0.98 µg/mL. Our results indicated that IJE exerted remarkable anti-fibrosis effect on BLM-induced pulmonary fibrosis in mice via inhibiting sEH activity, resulting in the regulation of GSK3ß signaling pathway. Our findings revealed the underlying action mechanism of I. japonica, and suggested that I. japonica could be regarded as a candidate resource for the treatment of pulmonary fibrosis.

Protostane-type triterpenoids as natural soluble epoxide hydrolase inhibitors: Inhibition potentials and molecular dynamics.

The inhibition of soluble epoxide hydrolase (sEH) is a promising therapeutic approach to treat inflammation and other disorders. In our present investigation on searching for sEH inhibitors from traditional Chinese medicines, we found that Alisma orientale displayed inhibition of sEH. We constructed a small library of protostane-type triterpenoids (1-25) isolated from A. orientale, and screened their inhibitory activities. Alismanin B (1), 11-deoxy-25-anhydro alisol E (4), 11-deoxy alisol B (5), and 25-O-ethyl alisol A (15) displayed concentration-dependently inhibitory activities against sEH with IC50 values from 3.40 ± 0.57 µM to 9.57 ± 0.88 µM. 11-Deoxy-25-anhydro alisol E (4) and 11-deoxy alisol B (5) were defined as mixed-type competitive inhibitors with Ki values of 12.6 and 3.48 µM, respectively, based on the result of inhibition kinetics. The potential interaction mechanism of 11-deoxy alisol B (5) with sEH was analyzed by molecular docking and molecular dynamics, revealing that amino acid residues Trp336 and Tyr466 were vital for its inhibitory activity.

Uncarialins A-I, Monoterpenoid Indole Alkaloids from Uncaria rhynchophylla as Natural Agonists of the 5-HT1A Receptor.

Nine new monoterpenoid indole alkaloids, uncarialins A-I (1-9), were isolated from Uncaria rhynchophylla as well as 14 known analogues (10-23). Their structures were determined by HRESIMS, 1D and 2D NMR, and experimental and calculated electronic circular dichroism data. Compounds 5, 7, 15, and 22 displayed significant agonistic effects against the 5-HT1A receptor with EC50 values of 2.2 ± 0.1, 0.1 ± 0.1, 1.6 ± 0.3, and 2.0 ± 0.5 µM, respectively. The mechanisms of action of these four compounds with the 5-HT1A receptor were investigated by molecular docking, and the results suggested that amino acid residues Asp116, Thr196, Asn386, and Tyr390 played critical roles in the observed activity of the above-mentioned compounds.

Demethylbellidifolin isolated from Swertia bimaculate against human carboxylesterase 2: Kinetics and interaction mechanism merged with docking simulations.

In this study, forty-nine kinds of traditional Chinese medicines (TCMs) were evaluated for their inhibitory activities against human carboxylesterase 2 (HCE 2) using a human liver microsome (HLM) system. Swertia bimaculata showed significant inhibition on HCE 2 at 10 µg/mL among forty-nine kinds of TCMs. The extract of Swertia bimaculata was separated by preparative HPLC to afford demethylbellidifolin (1) identified by MS, 1H NMR, and 13C NMR spectra. Demethylbellidifolin (1) was assayed for its inhibitory HCE 2 effect by HCE 2-mediated DDAB hydrolysis, and its potential IC50 value was 3.12 ±â€¯0.64 µM. Demethylbellidifolin (1) was assigned as a mixed-type competitive inhibitor with the inhibiton constant Ki value of 6.87 µM by Lineweaver-Burk and slope plots. Living cell imaging was conducted to corroborate its inhibitory HCE 2 activity. Molecular docking indicated potential interactions of demethylbellidifolin (1) with HCE 2 through two hydrogen bonds of the C-3 and C-5 hydroxy groups with amino acid residues Glu227 and Ser228 in the catalytic cavity, respectively.

Identification and Isolation of Glucosytransferases (GT) Expressed Fungi Using a Two-Photon Ratiometric Fluorescent Probe Activated by GT.

As is well-known, fungi are an important biocatalysis model of glucosylation and have been widely applied for bioactive compounds glucosylation mediated by the intracellular glucosytransferases (GTs). However, there is no efficient method for the real-time detection of GTs and the rapid isolation of the target fungi strains with the high expression of GTs. In the present work, we first developed a two-photon ratiometric fluorescent probe N-( n-butyl)-4-hydroxy-1,8-naphthalimide (NHN) for detecting the glucosyltransferases activity and intracellular imaging of GTs. Under UV light (365 nm), the transformed product of NHN mediated by intracellular glucosyltransferase displayed blue emission to guide the rapid isolation of fungal strains possessing overexpression of GTs from complex soil samples. Finally, by using the fluorescent probe, two target fungi were isolated and identified to be Rhizopus oryzae and Mucor circinelloides by molecular analysis, and they exhibited a robust capability for regio- and stereospecific O-glycosylation. Our results fully demonstrated that NHN may be a promising tool for guiding real-time GTs activity in fungal strains and even for developing natural fungal strains with GTs overexpression.

Isolation of γ-Glutamyl-Transferase Rich-Bacteria from Mouse Gut by a Near-Infrared Fluorescent Probe with Large Stokes Shift.

Bacterial γ-glutamyltranspeptidases (γ-GT) is a well-known metabolic enzyme, which could cleave the γ-glutamyl amide bond of γ-glutamyl analogues. As a key metabolic enzyme of bacteria and a virulence factor for the host, bacterial γ-GT was determined to be a novel pharmaceutical target for new antibiotics development. However, there is no efficient method for the sensing of γ-GT activity in bacteria and the recognition of γ-glutamyltransferase rich-bacteria. In the present work, a dicyanoisophorone derivative (ADMG) has been designed and developed to be a sensitive and selective near-infrared fluorescent probe for the sensing of bacterial γ-GT. ADMG not only sensed bacterial γ-GT in vitro, but also imaged intestinal bacteria in vivo. More interesting, the intestinal bacteria existed in the duodenum section of mouse displayed significant fluorescence emission. Under the guidance of the sensing of γ-GT using ADMG, three intestinal bacteria strains K. pneumoniae CAV1042, K. pneumoniae XJRML-1, and E. faecalis were isolated successfully, which expressed the bacterial γ-GT. Therefore, the fluorescent probe ADMG not only sensed the endogenous bacterial γ-GT and imaged the intestinal bacteria but also guided the isolation of intestinal bacteria possessing γ-GT efficiently, which suggested a novel biological tool for the rapid isolation of special bacteria from a mixed sample.

Uncaria rhynchophylla Ameliorates Parkinson's Disease by Inhibiting HSP90 Expression: Insights from Quantitative Proteomics.

BACKGROUND/AIMS: Uncaria rhynchophylla, known as "Gou-teng", is a traditional Chinese medicine (TCM) used to extinguish wind, clear heat, arrest convulsions, and pacify the liver. Although U. rhynchophylla has a long history of being often used to treat central nervous system (CNS) diseases, its efficacy and potential mechanism are still uncertain. This study investigated neuroprotective effect and the underlying mechanism of U. rhynchophylla extract (URE) in MPP+-induced SH-SY5Y cells and MPTP-induced mice. METHODS: MPP+-induced SH-SY5Y cells and MPTP-induced mice were used to established Parkinson's disease (PD) models. Quantitative proteomics and bioinformatics were used to uncover proteomics changes of URE. Western blotting was used to validate main differentially expressed proteins and test HSP90 client proteins (apoptosis-related, autophagy-related, MAPKs, PI3K, and AKT proteins). Flow cytometry and JC-1 staining assay were further used to confirm the effect of URE on MPP+-induced apoptosis in SH-SY5Y cells. Gait analysis was used to detect the behavioral changes in MPTP-induced mice. The levels of dopamine (DA) and their metabolites were examined in striatum (STR) by HPLC-EC. The positive expression of tyrosine hydroxylase (TH) was detected by immunohischemical staining and Western blotting. RESULTS: URE dose-dependently increased the cell viability in MPP+-induced SH-SY5Y cells. Quantitative proteomics and bioinformatics results confirmed that HSP90 was an important differentially expressed protein of URE. URE inhibited the expression of HSP90, which further reversed MPP+-induced cell apoptosis and autophagy by increasing the expressions of Bcl-2, Cyclin D1, p-ERK, p-PI3K p85, PI3K p110α, p-AKT, and LC3-I and decreasing cleaved caspase 3, Bax, p-JNK, p-p38, and LC3-II. URE also markedly decreased the apoptotic ratio and elevated mitochondrial transmembrane potential (DΨm). Furthermore, URE treatment ameliorated behavioral impairments, increased the contents of DA and its metabolites and elevated the positive expressions of TH in SN and STR as well as the TH protein. CONCLUSIONS: URE possessed the neuroprotective effect in vivo and in vitro, regulated MAPK and PI3K-AKT signal pathways, and inhibited the expression of HSP90. U. rhynchophylla has potentials as therapeutic agent in PD treatment.

Drechmerin H, a novel 1(2), 2(18)-diseco indole diterpenoid from the fungus Drechmeria sp. as a natural agonist of human pregnane X receptor.

A novel 1(2), 2(18)-diseco indole diterpenoid, drechmerin H (1), was isolated from the fermentation broth of Drechmeria sp. together with a new indole diterpenoid, 2'-epi terpendole A (3), and a known analogue, terpendole A (2). Their structures were determined by HRESIMS, 1D and 2D NMR, ECD, and X-ray single crystal diffraction analyses as well as quantum chemical calculation. The abosulte configuration of terpendole A (2) was determined for the first time. Compound 1 displayed the significant agonistic effect on pregnane X receptor (PXR) with EC50 value of 134.91 ±â€¯2.01 nM, and its interaction with PXR was investigated by molecular docking. Meantime, a plausible biosynthetic pathway for compounds 1-3 is also discussed in the present work.

Mangrove Tirucallane- and Apotirucallane-Type Triterpenoids: Structure Diversity of the C-17 Side-Chain and Natural Agonists of Human Farnesoid/Pregnane⁻X⁻Receptor.

Ten new triterpenoid compounds with structure diversity of the C-17 side-chain, including nine tirucallanes, named xylocarpols A⁻E (1⁻5) and agallochols A⁻D (6⁻9), and an apotirucallane, named 25-dehydroxy protoxylogranatin B (10), were isolated from the mangrove plants Xylocarpus granatum, Xylocarpus moluccensis, and Excoecaria agallocha. The structures of these compounds were established by HR-ESIMS and extensive one-dimensional (1D) and two-dimensional (2D) NMR investigations. The absolute configurations of 1 and 2 were unequivocally determined by single-crystal X-ray diffraction analyses, conducted with Cu Kα radiation; whereas those of 4, 6⁻8 were assigned by a modified Mosher's method and the comparison of experimental electronic circular dichroism (ECD) spectra. Most notably, 5, 6, 7, and 9 displayed potent activation effects on farnesoid⁻X⁻receptor (FXR) at the concentration of 10.0 µM; 10 exhibited very significant agonistic effects on pregnane⁻X⁻receptor (PXR) at the concentration of 10.0 nM.

Chemical characteristics of the fungus Ganoderma lucidum and their inhibitory effects on acetylcholinesterase.

The chemical characteristic of a well-known folk medicine Ganoderma lucidum has been investigated by a series of chromatographic technologies, which displayed the presences of 45 lanostane type triterpenoids, including two new nor-lanostane triterpenoids (40, 41). Their structures were identified on the basis of spectroscopic data analysis (UV, IR, HRESIMS, 1D, and 2D NMR). Notably, some triterpenoids displayed moderate inhibitory effects against AChE (acetylcholinesterase) by an in vitro screened experiment. Triterpenoid 2 displayed the potent inhibitory effect with IC50 10.8 and Ki 14.95 µM (inhibition kinetic). The preliminary SAR has been discussed by the docking analyses between ganoderic acids (1, 2) and AChE.

Diterpenoids from the roots of Euphorbia fischeriana and their inhibitory effects on α-glucosidase.

Chemical investigation has been performed on the roots of Euphorbia fischeriana, a traditional Chinese medicine. Three diterpenoids were obtained using various chromatographic techniques, and their structures were determined by spectroscopic data including HRESIMS, 1D NMR, 2D NMR, ECD, and calculated ECD, which gave two new diterpenoids, daphnane type (1) and ent-pimarene type (3). Additionally, the isolated compounds (1-3) displayed moderate inhibitory effects against α-glucosidase in an in vitro bioassay.

Cytotoxic and N-Acetyltransferase Inhibitory Meroterpenoids from Ganoderma cochlear.

Seven compounds, including two pairs of new meroterpenoids, (+)- and (-)-gancochlearol C (1), (+)- and (-)-cochlearoid Q (3), and a new meroterpenoid gancochlearol D (2), together with four known meroterpenoids were isolated from the aqueous EtOH extract of the fruiting bodies of Ganoderma cochlear. Their structures were determined by spectroscopic data. The isolated compounds were evaluated for their cytotoxic activity against three human lung cancer cells (H1975, PC9, A549) and N-acetyltransferase inhibitory property. The results show that (+)-gancochlearol C could inhibit N-acetyltransferase with an IC50 value of 5.29 µM. In addition, ganomycin F was found to show moderate activity against the H1975 human lung cancer cell line, with an IC50 value of 19.47 µM.

ent-Abietane and Tigliane Diterpenoids from the Roots of Euphorbia fischeriana and Their Inhibitory Effects against Mycobacterium smegmatis.

An investigation on the bioactive chemical constituents of the roots of Euphorbia fischeriana has been conducted, with 21 diterpenoids obtained using various chromatographic techniques. On the basis of spectroscopic data analysis, the new compounds were elucidated as four ent-abietane-type diterpenoids (1-4) and four tigliane-type diterpenoids (13-16). Also obtained were eight known ent-abietane (5-12) and five known tigliane (17-21) diterpenoids. The potential antituberculosis effects of these diterpenoids were evaluated using a Mycobacterium smegmatis model. The most potent compound according to the in vitro bioassay used was 17-hydroxyjolkinolide B (12) (MIC 1.5 µg/mL).

[Phenolic acid derivatives of Euphorbia ebracteolata].

A variety of chromatographic methods were applied to research the chemical composition of the roots of Euphorbia ebracteolata. Meanwhile, the structures of these compounds were identified by spectroscopic data, such as 1D, 2D NMR and HR-ESI-MS. In the present research, a new phenolic acid compound, 1,3,4,5-tetrahydroxy-2-O-ß-D-[(6'-Gallic acyl)-glucopyranyl] isopentane(1), was isolated from the roots of E. ebracteolata, as well as three known compounds, isopropyl-2-O-ß-D-(6'-gallic acyl)-glucopyranoside(2), ellagic acid(3) and 3,4'-di-O-methylellagic acid(4) respectively. Additionally, compounds 2 and 4 were isolated from the Euphorbia genus for the first time.

[Chemical Constituents of the Aerial Parts from Plumbago zeylanica].

Objective: To study the anti-oxidative constituents of the aerial parts of Plumbago zeylanica. Methods: The ethanol extract of Plumbago zeylanica was separated and purified by various chromatographic techniques. On the basis of various spectroscopic data, the structures of isolated compounds were elucidated. ABTS+radical scavenging were carried out in antioxidant activity evaluation of the isolated compounds. Results: Eleven compounds were isolated and identified as cis-isoshinanolone-4-O-ß-D-glucopyranoside( 1),tachioside( 2),2,6-dimethoxy-p-hydroquinone-1-O-ß-D-glucopyranoside( 3),3-( ß-D-glucopyranosyloxy)-4-methoxybenzoic acid( 4),3'-O-ß-D-glucopyranosyloxy-plumbagic acid( 5),3'-O-ß-D-glucopyranosyloxy-plumbagic acid methyl ester( 6),plumbagic acid( 7),plumbagine A( 8),plumbagine C( 9),syringate-4-O-ß-D-glucopyranoside( 10) and 2-methyl-5-hydroxychromone( 11). Compounds 2,3,and5 displayed significant scavenging effect on ABTS+. Conclusion: Compounds 1 ~ 4,10,11 are obtained from this plant for the first time. Compounds 2,3,and 5 show significant anti-oxidative effects.