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.

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.

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.

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.

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].

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.

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].

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.

[Water soluble constituents from the twigs of Litsea cubeba].

Twenty five known aromatic glycosides (1-25) and three known sesquiterpene glycosides (26-28) have been isolated from the twigs of Litsea cubeba by using various chromatographic techniques. Their structures were identified by spectroscopic data analysis (MS, IR, 1D and 2D NMR) as (7S,8R)-dehydrodiconiferyl alcohol 4,9'-di-O-ß-D-glucopyranoside(1),(7S,8R)-5-methoxydihydrodehydrodiconiferyl alcohol 4-O-ß-D-glucopyranoside(2), (7S,8R)-urolignoside(3), (7R,8S)-dihydrodehydrodiconiferyl alcohol 4-O-ß-D-glucopyranoside(4), saposide B(5), lanicepside A(6), matairesinol-4-O-ß-D-glucopyranoside (7), tyraxjaponoside B(8), (+)-lyoniresinol-9'-O-ß-D-glucopyranoside (9), alaschanisoside A (10), syringin (11), psoralenoside (12), isopsoralenoside (13), scopolin(14), 2,6-dimethoxy-4-hydroxyphenol-1-O-ß-D-glucopyranoside (15), 3-hydroxy-4,5-dimethoxyphenyl-ß-D-glucopyranoside (16), 2-(3,4-dihydroxyphenyl)ethyl-ß-D-glucopyrnoside (17), 2-(4-dihydroxyphenyl)ethyl-ß-D-glucopyranoside (18), (+)-catechin-7-O-ß-D-glucopyranoside (19), 3'-O-methylepicatechin-7-O-ß-D-glucopyranoside (20), kaempferitrin (21), quercetin-3-O-α-L-rhamnopyranside (22), kaempferol-3-O-ß-D-glucopyranoside (23), kaempferol 3-O-ß-D-glucopyranosyl(1→2)-O-ß-D-galactopyr anoside-7-O-α-L-rhamnopyranoside (24), quercetin 3-O-α-L-rhamnopyranosyl(1→6)-O-ß-D-glucopyranosyl(1→3)-O-α-L-rhamnopyranosyl(1→2)-O-ß-D-glucopyranoside (25), staphylionoside D(26), vomifoliol 9-O-ß-D-glucopyranoside (27), dihydrovomifoliol-O-ß-D-glucopyranoside (28). Compounds 1-21 and 24-28 were obtained from this genus for the first time.

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.

New Anti-HBV C-Boivinopyranosyl Flavones from Alternanthera philoxeroides.

C-boivinopyranosyl flavones have rarely been isolated from nature. In the search for anti-HBV (hepatitis b virus) constituents of Alternanthera philoxeroides, two new compounds, luteolin-6-C-ß-D-boivinopyranosyl-3'-O-ß-D-glucopyranoside (1) and chrysoeriol-6-C-ß-D-boivinopyranosyl-4'-O-ß-D-glucopyranoside (2), along with three known C-boivinopyranosyl flavones (compounds 3-5) were isolated. Their structures were determined by spectroscopic analyses including 1D and 2D NMR, HR-ESI-MS, IR spectra. Compounds 1, 2 and 3 showed significant anti-HBV activities through specifically inhibiting the secretion of HBsAg in HepG2.2.15.

[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).

[Chemical constituents from ethyl acetate exaction of root of Paeonia lactiflora].

Two new phenylpropanoids(1 and 2), together with thirteen known compounds(3-15), have been isolated from the root of Paeonia lactiflora by using various chromatographic techniques. Their structures were identified by spectroscopic data analysis(MS,IR,1D and 2D NMR)as(+)-(7R,8R)-1-guaiacyl-1,2-propanediolacetonide(1),(-)-(7R,8S)-1-guaiacyl-1,2-propanediolacetonide(2),O-senecioyllomatin(3),O-angeloyllomatin(4),(+)-cis-3'-senecioyloxy-4'-angeloyloxy-3',4'-dihydroseselin(5),columbianadin(6), benzyl 2,5-dihydroxybenzoate(7),3,6-dimethyl-5-hydroxyBenzo-furan(8),(S)-evofolin-A(9),2,3-dihydroxy-4-methoxyacetophenone(10), 2,5-dihydroxy-4-methoxyacetophenone(11), 2,5-dihydroxy-4-methyl acetophenone(12),ethyl 4-hydroxybenzoate(13), vanillic acid(14),and 4-hydroxy-3-methoxybenzaldehyde(15).Compounds 1 and 2 were new compounds,and compounds 3-9 were obtained from the genus Paeonia for the first time.

C14-polyacetylenol glycosides from the roots of Codonopsis pilosula.

Eight new C14-polyacetylenol glycosides, containing ene-diyne and ene-yn-ene chromophores named codonopilodiynosides H-M (1-6) and codonopiloenynenosides A and B (7 and 8), respectively, together with three known analogs lobetyolinin, pratialin B, and lobetyolin (9-11), were isolated from an aqueous extract of the roots of Codonopsis pilosula. Their structures were determined by spectroscopic and chemical methods including 2D NMR data analysis and enzymatic hydrolysis. The absolute configurations of aglycones in 1-10 were assigned by application of the methoxyphenylacetic acid (MPA) determination rule of Δδ(RS) values and/or the empirical rule of Mo2(OAc)4-induced circular dichroism for the vicinal diols, or by comparison of specific rotation values with those of reported compounds. Compounds 4-6 are the first polyacetylenol glycosides possessing a cis-ene-diyne chromophore from the genus Codonopsis, while 8 has a rear trans-ene-yn-cis-ene chromophore and a (6S,7S)-6,7-diol unit against a (6R,7R)-6,7-diol unit in the others. The absolute configurations of lobetyolinin (9) and pratialin B (10) were determined for the first time.

C14-polyacetylene glucosides from Codonopsis pilosula.

Seven new C14-polyacetylene glucosides codonopilodiynosides A-G (1-7) were isolated from an aqueous extract of the Codonopsis pilosula roots. Their structures were determined by spectroscopic and chemical methods as (-)-(5S,6E,12E)-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5-O-ß-D-glucopyranoside (1), (-)-(5S,6E,12E)-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5-O-ß-D-glucopyranosyl-(1″ → 2')-ß-D-glucopyranoside (2), (-)-(5S,6E,12E)-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5,14-di-O-ß-D-glucopyranoside (3), (-)-(5S,6E)-tetradeca-6-en-8,10-diyn-1,5,14-triol 5-O-ß-D-glucopyranoside (4), (-)-(5S,6E,12E)-tetradeca-6,12-dien-8,10-diyn-1,5-diol 5-O-ß-D-glucopyranosyl-(1″ → 2')-ß-D-glucopyranoside (5), (-)-(6S,4E,12E)-tetradeca-4,12-dien-8,10-diyn-1,6-diol 6-O-ß-D-glucopyranosyl-(1″ → 2')-ß-D-glucopyranoside (6), and (-)-(5S,6E)-tetradeca-6-en-1,5-epoxy-8,10-diyn-14-ol 14-O-ß-D-glucopyranosyl-(1″ → 2')-ß-D-glucopyranoside (7), respectively. The absolute configurations of 1-7 were assigned by enzymatic hydrolysis followed by isolation of glucose and aglycones (1a and 4a-7a), and subsequent comparison of specific rotation, TLC, and (1)H NMR data of the glucose with an authentic sugar sample and application of modified Mosher's method based on the MPA determination rule of Δδ(RS) values for 1a and 4a, and Δδ(S) values for 6a. The configuration of 7 was assigned by electronic circular dichroism calculations based on the quantum-mechanical time-dependent density functional theory.

Antiviral glycosidic bisindole alkaloids from the roots of Isatis indigotica.

Seven new glycosidic bisindole alkaloids, isatindigobisindolosides A-G (1-7), were isolated from an aqueous extract of the Isatis indigotica roots. Their structures including absolute configurations were determined by spectroscopic and chemical methods, together with calculations of electronic circular dichroism (ECD) spectra based on the quantum-mechanical time-dependent density functional theory. In the NMR spectra of 1-3, it is found that integration of H-2 and intensity of C-2 are affected not only by a substitution group at C-2 but also by solvents. Influences of the glucopyranosyloxy on the calculated ECD spectra of the glycosidic bisindole alkaloids are discussed. Compounds 2, 5, and 6 showed antiviral activity against both the influenza virus A/Hanfang/359/95 (H3N2) and Coxsackie virus B3 with IC50 values of 8.4-100.0 µM.

4-Hydroxybenzyl-substituted glutathione derivatives from Gastrodia elata.

Seven new 4-hydroxybenzyl-substituted glutathione derivatives (2-8), together with a known analogue (1), were isolated from the aqueous extract of Gastrodia elata Blume rhizomes. Their structures were determined by using spectroscopic and chemical methods. The absolute configurations of 1-8 were assigned by using Marfey's method, combined with comparing the NMR and CD spectroscopic data of sulfoxide moieties in 3-6 with those of S-(4-hydroxybenzyl)cysteine sulfoxide stereoisomers (9-12) synthesized as authentic samples. The configurations of 9-12 were confirmed by electronic CD calculations based on the quantum-mechanical time-dependent density functional theory. Furthermore, the structures of 1, 3, 5, 7, and 8 were verified by synthesis. Compound 3 was active against serum deprivation-induced PC12 cell damage and synthetic 9-14 exhibited activity against Fe(2+)-cysteine induced rat liver microsomal lipid peroxidation.