Minor alkaloids from an aqueous extract of the hook-bearing stem of Uncaria rhynchophylla.

Seven new monoterpene alkaloids (1 - 7), along with 16 known analogues, were isolated from an aqueous decoction of the hook-bearing stems of Uncaria rhynchophylla (Gou-teng). Their structures were determined by spectroscopic data analysis, single crystal X-ray diffraction, and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 are stereoisomers belonging to a novel type of pseudoindoxyl monoterpene alkaloids, 3 is the first monoterpene furoindole alkaloid from nature, and 4 - 7 are derivatives of the known monoterpene alkaloids featuring different structures.

Diverse neolignans and lignans from an aqueous extract of the Angelica sinensis root head.

Neolignans and lignans with diverse new chemical structures, including eleven pairs of separated chiral enantiomers [(+)-/(-)-1-(+)-/(-)-5, (+)-/(-)-8, (+)-/(-)-10, and (+)-/(-)-12-(+)-/(-)-15], two achiral compounds (6 and 9), and an unseparated racemate [(±)-11], together with a new natural product (7) and 21 known derivatives, were isolated from an aqueous extract of the Angelica sinensis root head (guitou). Among the chiral isolates, (+)-/(-)-13 and (+)-/(-)-15 were scalemic pairs with enantiomeric ratios of around 3:1 and 1.5:1, respectively, while others were enantiomeric equivalent pairs. This indicates that the diverse neolignans in A. sinensis are biosynthesized via different pathways with varying degrees of stereo-controlled manners.

Sulfonated alkaloids from an aqueous extract of Isatis indigotica roots.

Eleven new sulfonated alkaloids (1 - 11) having diverse structures were isolated from an aqueous extract of the Isatis indigotica root (ban lan gen). Their structures were determined by spectroscopic data analysis, chemical method, and theoretical calculation, of which (-)-4 was proved by single crystal X-ray diffraction.

Minor monoterpene derivatives from an aqueous extract of the hook-bearing stem of Uncaria rhynchophylla.

Seven new minor monoterpene derivatives (1-7), together with six known analogues, were isolated from an aqueous decoction of the hook-bearing stems of Uncaria rhynchophylla (Gou-teng). Their structures were determined by spectroscopic data analysis and electronic circular dichroism (ECD) calculations, of which 1 was confirmed by single crystal X-ray diffraction.

Lignans and a neolignan from an aqueous extract of Isatis indigotica roots.

Four new lignans (1-4) and one new neolignan (5), along with two known lignan derivatives (6 and 7), were isolated from an aqueous extract of the Isatis indigotica root (ban lan gen). Their structures were determined by spectroscopic data analysis, chemical method, and theoretical calculation, for which 1 was proved by single-crystal X-ray diffraction. Compound 2 exhibited antiviral activity against influenza virus A/Hanfang/359/95 (H3N2) with an IC50 value of 11.1 µM and a selective index (SI) > 9, while 1 and 5 are the first examples of sulfonated lignan and neolignan from nature.

Divanillyl sulfone suppresses NLRP3 inflammasome activation via inducing mitophagy to ameliorate chronic neuropathic pain in mice.

BACKGROUND: Chronic neuropathic pain is a frequent sequel to peripheral nerve injury and maladaptive nervous system function. Divanillyl sulfone (DS), a novel structural derivative of 4,4'-dihydroxydibenzyl sulfoxide from a traditional Chinese medicine Gastrodia elata with anti-nociceptive effects, significantly alleviated neuropathic pain following intrathecal injection. Here, we aimed to investigate the underlying mechanisms of DS against neuropathic pain. METHODS: A chronic constrictive injury (CCI) mouse model of neuropathic pain induced by sciatic nerve ligation was performed to evaluate the effect of DS by measuring the limb withdrawal using Von Frey filament test. Immunofluorescence staining was used to assess the cell localizations and expressions of Iba-1, ASC, NLRP3, and ROS, the formation of autolysosome. The levels of NLRP3-related proteins (caspase-1, NLRP3, and IL-1ß), mitophagy-related proteins (LC3, Beclin-1, and p62), and apoptosis-related proteins (Bcl-XL and Bax) were detected by Western blotting. The apoptosis of BV-2 cell and caspase activity were evaluated by flow cytometry. RESULTS: DS significantly alleviated the neuropathic pain by increasing the mechanical withdrawal threshold and inhibiting the activation of NLRP3 in CCI-induced model mice. Our findings indicated that DS promoted the mitophagy by increasing the LC3II and Beclin 1 and decreasing the levels of p62 protein in BV-2 cell. This is accompanied by the inhibition of NLRP3 activation, which was shown as inhibited the expression of NLRP3 in lysates as well as the secretion of mature caspase-1 p10 and IL-1ß p17 in supernatants in cultured BV-2 microglia. In addition, DS could promote mitophagy-induced improvement of dysfunctional mitochondria by clearing intracellular ROS and restoring mitochondrial membrane potential. CONCLUSION: Together, our findings demonstrated that DS ameliorate chronic neuropathic pain in mice by suppressing NLRP3 inflammasome activation induced by mitophagy in microglia. DS may be a promising therapeutic agent for chronic neuropathic pain.

Minor alkaloids from an aqueous extract of the hook-bearing stem of Uncaria rhynchophylla.

Seven new monoterpene alkaloids (1-7), along with 18 known analogues, were isolated from an aqueous decoction of the hook-bearing stems of Uncaria rhynchophylla (Gou-teng). Their structures were determined by spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Compound 1 is the first monoterpene 22-norindoloquinolizidine alkaloid with a ketene unit, while 2 and 3 are unusual indoloquinolizidine alkaloids having an oxazinane ring.[Formula: see text].

Minor triterpenes from an aqueous extract of the hook-bearing stem of Uncaria rhynchophylla.

Six new triterpenes, uncarinic acids KP (1-6), along with 24 known analogues, were isolated as minor constituents of an aqueous decoction of the hook-bearing stems of Uncaria rhynchophylla (Gou-teng). By comprehensive spectroscopic data analysis, their structures were elucidated as derivatives of olean-12-en-28-oic acid and urs-12-en-28-oic acid with different oxidized forms at C-3, C-6, and/or C-23, respectively. Cell-based preliminary bioassay showed that the (E)-/(Z)-coumaroyloxy and (E)-/(Z)-feruloyloxy units at C-27 of olean-12-en-28-oic acid and urs-12-en-28-oic acid played roles in their bioactivities.[Formula: see text].

Denudatine-type diterpenoid alkaloids from an aqueous extract of the lateral root of Aconitum carmichaelii.

Five new denudatine-type diterpenoid alkaloids (1-5), along with the known analogue aconicarmine (6), were isolated from an aqueous decoction of the lateral roots of Aconitum carmichaelii (fu-zi). Their structures were determined by spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Compound 5 is the first denudatine-type diterpenoid alcohol iminium alkaloid, which could be partially transformed into the aza acetal form in pyridine-d5. Compound 5 inhibited mice writhing in an acetic acid-induced writhing assay.

Isotalatizidine, a C19-diterpenoid alkaloid, attenuates chronic neuropathic pain through stimulating ERK/CREB signaling pathway-mediated microglial dynorphin A expression.

BACKGROUND: Isotalatizidine is a representative C19-diterpenoid alkaloid extracted from the lateral roots of Aconitum carmichaelii, which has been widely used to treat various diseases on account of its analgesic, anti-inflammatory, anti-rheumatic, and immunosuppressive properties. The aim of this study was to evaluate the analgesic effect of isotalatizidine and its underlying mechanisms against neuropathic pain. METHODS: A chronic constrictive injury (CCI)-induced model of neuropathic pain was established in mice, and the limb withdrawal was evaluated by the Von Frey filament test following isotalatizidine or placebo administration. The signaling pathways in primary or immortalized microglia cells treated with isotalatizidine were analyzed by Western blotting and immunofluorescence. RESULTS: Intrathecal injection of isotalatizidine attenuated the CCI-induced mechanical allodynia in a dose-dependent manner. At the molecular level, isotalatizidine selectively increased the phosphorylation of p38 and ERK1/2, in addition to activating the transcription factor CREB and increasing dynorphin A production in cultured primary microglia. However, the downstream effects of isotalatizidine were abrogated by the selective ERK1/2 inhibitor U0126-EtOH or CREB inhibitor of KG-501, but not by the p38 inhibitor SB203580. The results also were confirmed in in vivo experiments. CONCLUSION: Taken together, isotalatizidine specifically activates the ERK1/2 pathway and subsequently CREB, which triggers dynorphin A release in the microglia, eventually leading to its anti-nociceptive action.

Discovery of a semi-synthesized cyclolignan as a potent HIV-1 non-nucleoside reverse transcriptase inhibitor.

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are essential components of highly active antiretroviral therapy (HAART) for human immunodeficiency virus type 1 (HIV-1) infection. In this study, we identified (+)-(7'S,8S,8'S)-3',4,4',5,5'-pentamethoxy-2,7'-cyclolignan (SG-1), a cyclolignan semi-synthesized from Machilus robusta and M. wangchiana extracts, as a potent NNRTI. SG-1 displayed anti-HIV-1 activity with an IC50 of 0.77 µmol/L by inhibiting reverse transcriptase (RT) RNA-dependent DNA polymerase activity through a direct binding. It had synergistic effects when combined with tenofovir/lamivudine or zidovudine/lamivudine. The pharmacodynamics properties of SG-1 render it a valuable lead for the development of novel NNRTIs.

Diglycosidic indole alkaloid derivatives from an aqueous extract of Isatis indigotica roots.

Six new indole alkaloid diglycosides named isatigotindolediosides A-F (1-6), along with three known analogs (7-9), were isolated from an aqueous extract of the Isatis indigotica roots (ban lan gen). Their structures including the absolute configurations were determined by comprehensive spectroscopic data analysis, combined with enzyme or acid hydrolysis, and comparison of experimental circular dichroism (CD) and calculated electronic circular dichroism (ECD) spectra. In the preliminary assays, compounds 3, 5, and 8 showed antiviral activity against Coxsackie virus B3.

Bioactive Benzofuran Derivatives from Cortex Mori Radicis, and Their Neuroprotective and Analgesic Activities Mediated by mGluR1.

Four new benzofuran-type stilbene glycosides and 14 known compounds including 8 benzofuran-type stilbenes and 6 flavonoids were isolated from the traditional Chinese medicine, Cortex Mori Radicis. The new compounds were identified as (9R)-moracin P 3'-O-α-l-arabinopyranoside (1), (9R)-moracin P 9-O-ß-d-glucopyranoside (2), (9R)-moracin P 3'-O-ß-d-glucopyranoside (3), and (9R)-moracin O 10-O-ß-d-glucopyranoside (4) based on the spectroscopic interpretation and chemical analysis. Three benzofuran-type stilbenes, moracin O (5), R (7), and P (8) showed significant neuroprotective activity against glutamate-induced cell death in SK-N-SH cells. In addition, moracin O (5) and P (8) also demonstrated a remarkable inhibition of the acetic acid-induced pain. The molecular docking with metabotropic glutamate receptor 1 (mGluR1) results indicated that these neuroprotective benzofuran-type stilbenes might be the active analgesic components of the genus Morus, and acted by mediating the mGluR1 pathway.

20C, a bibenzyl compound isolated from Gastrodia elata, protects PC12 cells against rotenone-induced apoptosis via activation of the Nrf2/ARE/HO-1 signaling pathway.

AIM: Our preliminary study shows that a bibenzyl compound isolated from Gastrodia elata, 2-[4-hydroxy-3-(4-hydroxybenzyl)benzyl]-4-(4-hydroxybenzyl)phenol (designated 20C), protects PC12 cells against H2O2-induced injury. In this study we investigated whether 20C exerted neuroprotective action in a cell model of Parkinson's disease. METHODS: A cell model of Parkinson's disease was established in PC12 cells by exposure to rotenone (4 µmol/L) for 48 h. Cell viability and apoptosis were assessed, and intracellular ROS level and the mitochondrial membrane potential (MMP) were detected. The expression of apoptosis-related proteins Bax, Bcl-2, cytochrome c, cleaved caspase-3, and oxidative stress-related proteins Nrf2, HO-1 and NQO1 were examined using Western blotting. The mRNA levels of HO-1 and NQO1 were determined with RT-PCR. The nuclear translocation of Nrf2 was observed with immunofluorescence staining. RESULTS: Treatment with rotenone significantly increased the number of apoptotic cells, accompanied by marked increases in the Bax/Bcl-2 ratio, cytochrome c release and caspase-3 activation. Rotenone also increased ROS accumulation, reduced MMP, and increased the nuclear translocation of Nrf2 as well as the mRNA and protein levels of the Nrf2 downstream target genes HO-1 and NQO1 in PC12 cells. Co-treatment with 20C (0.01-1 µmol/L) dose-dependently attenuated rotenone-induced apoptosis and oxidative stress in PC12 cells. Nrf2 knockdown by siRNA partially reversed the protective effects of 20C in rotenone-treated PC12 cells. CONCLUSION: The bibenzyl compound 20C protects PC12 cells from rotenone-induced apoptosis, at least in part, via activation of the Nrf2/ARE/HO-1 signaling pathway.

Bibenzyl compound 20c protects against endoplasmic reticulum stress in tunicamycin-treated PC12 cells in vitro.

AIM: Accumulation of α-synuclein (α-syn) in the brain is a characteristic of Parkinson's disease (PD). In this study, we investigated whether treatment with tunicamycin, an endoplasmic reticulum (ER) stress inducer, led to the accumulation of α-syn in PC12 cells, and where α-syn protein was accumulated, and finally, whether bibenzyl compound 20c, a novel compound isolated from Gastrodia elata (Tian ma), could alleviate the accumulation of α-syn and ER stress activation in tunicamycin-treated PC12 cells. METHODS: PC12 cells were treated with tunicamycin for different time (6 h, 12 h, 24 h, 48 h). Cell viability was determined by a MTT assay. Subcellular fractions of ER and mitochondria were extracted with the Tissue Endoplasmic reticulum Isolation Kit. The levels of α-syn protein and ER-stress-associated downstream chaperones were detected using Western blots and immunofluorescence. RESULTS: Treatment of PC12 cells with tunicamycin (0.5-10 µg/mL) dose-dependently increased the accumulation of α-syn monomer (19 kDa) and oligomer (55 kDa), and decreased the cell viability. Accumulation of the two forms of α-syn was observed in both the ER and mitochondria with increasing treatment time. Co-treatment with 20c (10-5 mol/L) significantly increased the viability of tunicamycin-treated cells, reduced the level of α-syn protein and suppressed ER stress activation in the cells, evidenced by the reductions in phosphorylation of eIF2α and expression of spliced ATF6 and XBP1. CONCLUSION: Tunicamycin treatment caused accumulation of α-syn monomer and oligomer in PC12 cells. Bibenzyl compound 20c reduces the accumulation of α-syn and inhibits the activation of ER stress, which protected PC12 cells against the toxicity induced by tunicamycin.

Interaction effects on cytochrome P450 both in vitro and in vivo studies by two major bioactive xanthones from Halenia elliptica D. Don.

The major components, 1-hydroxy-2,3,5-trimethoxy-xanthone (HM-1) and 1,5-dihydroxy-2,3-dimethoxy-xanthone (HM-5) isolated from Halenia elliptica D. Don (Gentianaceae), could cause vasodilatation in rat coronary artery with different mechanisms. In this work, high-performance liquid chromatography coupled to ion trap time-of-flight mass spectrometry (LCMS-IT-TOF) was used to clarify the metabolic pathways, and CYP450 isoform involvement of HM-1 and HM-5 were also studied in rat. At the same time, in vivo inhibition effects of HM-1 and ethyl acetate extracts from origin herb were studied. Three metabolites of HM-5 were found in rat liver microsomes (RLMs); demethylation and hydroxylation were the major phase I metabolic reactions for HM-5. Multiple CYP450s were involved in metabolism of HM-1 and HM-5. The inhibition study showed that HM-5 inhibited Cyp1a2, 2c6 and 2d2 in RLMs. HM-1 inhibited activities of Cyp1a2, Cyp2c6 and Cyp3a2. In vivo experiment demonstrated that both HM-1 and ethyl acetate extracts could inhibit Cyp3a2 in rats. In conclusion, the metabolism of xanthones from the origin herb involved multiple CYP450 isoforms; in vitro, metabolism of HM-5 was similar to that of its parent drug HM-1, but their inhibition effects upon CYP450s were different; in vivo, Cyp3a2 could be inhibited by HM-1 and ethyl acetate extracts.

Indole alkaloid glucosides from the roots of Isatis indigotica.

Five new indole alkaloid glucosides named isatindigotindolosides A-E (1-5), along with three known analogs (6-8), were isolated from an aqueous extract of the Isatis indigotica roots. Their structures including the absolute configurations were determined based on comprehensive spectroscopic data analysis, combined with chemical methods and electronic circular dichroism spectra calculations. In the preliminary assays, compounds 1, 6 and 7 showed antiviral activity against influenza virus A/Hanfang/359/95 (H3N2) with IC50 values of 14.6-33.3 µM. Compound 1 also exhibited inhibitory effect against nitric oxide (NO) production in microglial cell BV2 with an inhibition ratio of 93.0% at 10 µM.

[Terpenoids from Euphorbia micractina].

From an ethanol extract of Euphorbia micractina roots, sixteen terpenoids were isolated by a combination of various chromatographic techniques, including column chromatography over macroporous resin, silica gel, and Sephadex LH-20 and reversed-phase HPLC. Their structures were elucidated by spectroscopic data analysis as loliolide myristate(1), 24-methylenetirucall-8-en-3ß,11α-diol-7-one(2), loliolide(3), 3ß-hydroxy- 5α,6α-epoxy-7-megastigmen-9-one(4), jolkinol A(5), jolkinol D(6), latilagascene F(7), helioscopinolide A(8), helioscopinolide B(9), 3-O-acetylhelioscopinolide B(10), helioscopinolide D(11), helioscopinolide E(12),(+)-11-acetoxyatis-16-en-3,14-dione(13), erythrodiol(14), uvaol(15) and betulin(16). All of the compounds were obtained from this plant for the first time, in which 1 and 2 are new compounds.

[Lignanoids from an aqueous extract of the roots of Codonopsis pilosula].

Sixteen lignanoids were isolated from an aqueous extract of the commonly used Chinese traditional medicine Dangshen, the dried roots of Codonopsis pilosula, by using a combination of various chromatographic techniques, including silica gel, macroporous adsorbent resin, MCI resin, sephadex LH-20, and reversed phase semi-preparative HPLC. On the basis of spectral data analysis, their structures were elucidated and identified as（-）-（7R,7'R,8R,8'S）-4,4'-dihydroxy-3,3',5,5',7-pentamethoxy-2,7'-cyclolignane（1）,（-）-（7R,8S）- dihydrodehydrodiconiferyl alcohol 4-O-ß-D-glucopyranosyl-（1'''→2''）-ß-D-glucopyranoside（2）,（-）-（7R,8S）- dihydrodehydrodiconiferyl alcohol（3）,（+）-（7S,8R）-dehydrodiconiferyl alcohol（4）,（+）-balanophonin（5）,（+）- demethoxypinoresinol（6）,（+）-pinoresinol（7）,（+）-epipinoresinol（8）,（-）-syringaresinol（9）,（-）-medioresinol（10）,（-）-lariciresinol（11）,（-）-secoisolariciresinol（12）,（-）-ent-isolariciresinol（13）,（+）-（7S,8S）-3-methoxy-3',7- expoxy-8,4'-neolignan-4,9,9'-triol（14）,（+）-（7S,8R）-3',4-dihydroxy-3-methoxy-8,4'-neolignan（15）, and（-）-（7R,8R）-3',4-dihydroxy-3-methoxy-8,4'-neolignan（16）. All these compounds were isolated from C. pilosula for the first time, while compound 1 is a new natural product of 2,7'-cyclolignan and 2 is a new 4',7-epoxy- 8,3'-neolignan diglucoside. Compound 12 showed activity against Fe(2+)-cysteine induced rat liver microsomal lipid peroxidation with an inhibition ratio of（63.4 ± 8.3） % at 1×10(-5) mol·L(-1).

[Structure-activity relationship of gastrodin and parishins on learning and memory deficits induced by scopolamine].

Gastrodin, parishin and parishin C were purified from a water extract of GE (rhizome of Gastrodia elata, an herb medicine for treatment of neuronal disorders). In order to compare the pharmacological effects of gastrodin, parishin and parishin C on improving cognition deficits, we tested them in an animal model of cognition disorders induced by scopolamine and in a study of in vivo long-term potentiation (LTP) recordings. In the Morris water maze task, parishin C (15 and 50 mg·kg(-1), P<0.05) and parishin (150 mg·kg(-1), P<0.05), improved spatial learning and memory significantly. However, gastrodin showed no significant effects at the dose of 150 mg·kg(-1). In vivo LTP recordings showed that parishin C at 5,10 and 20 mg·kg(-1), parishin at 10, 30 and 100 mg·kg(-1) reversed the suppression of LTP by scopolamine in rats in a dose-dependent manner. However, gastrodin at 100 mg·kg(-1) showed only a modest effect. In summary, the action of parishin C in the improvement of dementia induced by scopolamine was more potent than parishin and gastrodin.