Undescribed (2-7')-neolignans and polyoxygenated cyclohexene glycosides from the aerial parts of Piper mutabile C. DC. and their inhibitory effects on nitric oxide production

A phytochemical study of the aerial parts of Piper mutabile C. DC. revealed seven undescribed compounds [two (2-7')-neolignans and five polyoxygenated cyclohexene glycosides] and six known propenylcatechol derivatives. The chemical structures of the isolated compounds were elucidated by extensive HR-ESI-MS and NMR analyses, as well as comparison with the literature. The absolute configurations of the (2-7')-neolignans were confirmed by GIAO 13C NMR calculations with a sorted training set strategy and TD-DFT calculation ECD spectra. The (2-7')-neolignans and polyoxygenated cyclohexene glycosides are unusual in natural sources. Undescribed neolignans 1 and 2 inhibited NO production in RAW 264.7 cells, with respective IC50 values of 14.4 and 9.5 μM.

Cryptobuchanosides A-G: seven previously undescribed triterpene glycosides from Cryptolepis buchananii R.Br. ex Roem. and Schult. with nitric oxide production inhibition activity

In this study, nine triterpene glycosides including seven previously undescribed compounds (1-7), were isolated from leaves of Cryptolepis buchananii R.Br. ex Roem. and Schult. using various chromatographic methods. The chemical structures of the compounds were elucidated to be 3-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (1), 3-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (2), 3-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosyluncargenin C 28-O-β-D-glucopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (3), 3-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosylhederagenin 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (4), 3-O-β-D-glucopyranosylarjunolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (5), 3-O-β-D-glucopyranosyl-(1 → 2)-β- D-glucopyranosyl-6β,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (6), 3-O-β-D-glucopyranosyl-6β,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (7), asiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (8), and 3-O-β-D-glucopyranosylasiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (9), through infrared, high-resolution electrospray ionization mass spectrometry, one- and two-dimensional nuclear magnetic resonance spectral analyses. The isolates inhibited nitric oxide production in lipopolysaccharide-activated RAW 264.7 cells, with half-maximal inhibitory concentration (IC50) values of 18.8-58.5 µM, compared to the positive control compound, dexamethasone, which exhibited an IC50 of 14.1 µM.

Four Unidentified Compounds Isolated from the Stem Barks of Aphanamixis polystachya and Their NO Production Inhibition in LPS Activated RAW 264.7 Cells

Phytochemical study on the methanol extract of the stem barks of Aphanamixis polystachya led to the isolation of four previously undescribed ( 1-4) and ten known compounds (5-14). Their chemical structures were elucidated to be 11-methoxysawaranospiroride C (1), 6α,9S,10,13-tetrahydroxymegastigmane-3-one (2), 11-hydroxyaphanamixin B (3), (2Z,6E,13E)-2,6,13-triene-11,15-dihydroxyphytanic acid (4), cinnacasside D (5), cinnacasside E (6), vilsonol F (7), (3S,5R,6S,7E,9R)-3,5,6,9-tetrahydroxy-7-en-megastigmane (8), (3S,5R,6R,7E,9R)-3,6,9,10-tetrahydroxy-7-en-megastigmane (9), citroside A (10), threo-1-(3,4,5-trimethoxyphenyl)-1,2,3-propanetriol (11), 3,4,5-trimethoxyphenyl-1-O-β-D-glucopyranoside (12), p-coumaric acid (13), ferulic acid (14) by HR-ESI-MS, ECD, 1D-, and 2D-NMR spectra. Compounds 1, 3, 4, and 9 showed NO production inhibitory activity in LPS activated RAW 264.7 cells with IC50 values of 42.0, 67.9, 20.5, and 78.6 µM, respectively, while the remaining compounds were inactive with IC50 values over 100 µM.

Tributelosides A-D: Four Undescribed Spirostan Glycosides Isolated from the Branches and Leaves of Tribulus terrestris with Their NO Production Inhibitory Activity in LPS Activated RAW 264.7 Cells

Four undescribed spirostan glycosides, (25S)-5α-spirostan-12-one-2α,3β-diol-3-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside (1), (25S)-5α-spirostan-12-one-2α,3β-diol-3-O-β-D-galatopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside (2), (25S)-5α-spirostan-12-one-2α,3β-diol-3-O-β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside (3), and hecogenin 3-O-β-D-glucopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-D-galactopyranoside (4), together with eleven known compounds (5-15) were isolated from the branches and leaves of Tribulus terrestris. Their chemical structures were established through spectroscopic methods. including HR-ESI-MS, 1D-, and 2D-NMR spectra. Preliminary biological evaluation on NO production inhibitory activity in LPS activated RAW 264.7 cells showed that compounds 1-3, 5, and 6 had significant inhibitory effects with IC50 values ranging from 2.4 to 18.3 µM, compared to that of the positive control compound, dexamethazone (IC50 13.6 µM).

Discovery of new triterpene glycosides from Dendrobium officinale with their α-glucosidase and α-amylase inhibitory activity

In this study, seven new pentacyclic triterpene glycosides, named dendrocinaosides A-G (1-7), and six known ones (8-13) were isolated from the whole plants of Dendrobium officinale. Their structures were determined by analyses of HR-ESI-MS, 1D and 2D NMR spectra. Compounds 1-4, 8, and 9 potentially inhibited α-glucosidase and α-amylase activities with the IC50 values ranging from 31.3 ± 2.2 to 42.4 ± 2.5 μM for anti α-glucosidase and from 36.5 ± 1.8 to 56.4 ± 2.0 μM for anti α-amylase activities, respectively, which were lower than that of the positive control, acarbose, showing IC50 values of 47.1 ± 1.4 μM for anti α-glucosidase and 145.7 ± 2.2 μM for anti α-amylase.

Four Undescribed Stilbenoid Derivatives from the Aerial Parts of Dendrobium officinale with their α-Glucosidase and α-Amylase Inhibitory Activity

In this study, four undescribed bibenzyl derivatives (1-4), together with seven known compounds (5-11) were isolated from the aerial parts of Dendrobium officinale. Their chemical structures were determined to be (7'S,8'S) -9''-acetyldendrocandin U (1), (7'S,8'S) -4'-methoxydendrocandin T (2), (7'R,8'S) -dendrocandin B (3), (1S,2R) -5'''-methoxydendrofindlaphenol C (4) by analyzing of the spectroscopic data including HR-ESI-MS, 1D-, and 2D-NMR spectra. The absolute configurations of compounds 1-4 were determined by the electronic circular dichroism (ECD) spectra. Compounds 1-3, 5, 10 and 11 inhibited α-glucosidase with the IC50 values ranging from 56.3 to 165.3 μM, compounds 1-3, 5, 7-10 inhibited α-amylase with the IC50 values ranging from 65.2 to 177.6 μM.

Undescribed sesquiterpene-diterpene heterodimers from the fruits of Aphanamixis polystachya selectively modulate inflammatory markers in RAW 264.7 cells

Aphanapolystachones A-C (1-3), three undescribed sesquiterpene-diterpene heterodimers, were obtained from the fruits of Aphanamixis polystachya. Their structures and absolute configurations were identified by extensive analysis of HR-ESI-MS, NMR, experimental and TD-DFT calculated ECD spectra. The biosynthetic pathway of them was also proposed, which is produced by key intermolecular Diels-Alder [4 + 2]-cycloaddition reaction between a guaiane sesquiterpene and an acyclic diterpene. Compounds 1-3 inhibited NO production in LPS activated RAW 264.7 cells with the IC50 values of 1.7 ± 0.2, 3.0 ± 0.3, 5.3 ± 0.3 μM, respectively, lower than that of the positive control L-NMMA (31.5 ± 2.6 μM). In addition, compounds 1-3 significantly reduced IL-6 secretion at diluted concentration of 0.4 μM.

Alkaloids and Lignans from the Aerial Parts of Rauvolfia tetraphylla Inhibit NO Production in LPS-activated RAW 264.7 Cells

Three previously undescribed compounds named rauvolphyllas A-C (1-3), along with thirteen known compounds, 18β-hydroxy-3-epi-α-yohimbine (4), yohimbine (5), α-yohimbine (6), 17-epi-α-yohimbine (7), (E)-vallesiachotamine (8), (Z)-vallesiachotamine (9), 16S-E-isositsirikine (10), Nb -methylisoajimaline (11), Nb -methylajimaline (12), ajimaline (13), (+)-lyoniresinol 3α-O-β-D-glucopyranoside (14), (+)-isolarisiresinol 3α-O-β-D-glucopyranoside (15), and (-)-lyoniresinol 3α-O-β-D-glucopyranoside (16) were isolated from the aerial parts of Rauvolfia tetraphylla L. Their chemical structures were elucidated based on the extensive spectroscopic interpretation of HR-ESI-MS, 1D and 2D NMR spectra. The absolute configurations of 2 and 3 were determined by experimental ECD spectra. Compounds 5, 6, 7, and 11-13 exhibited nitric oxide production inhibition activity in LPS-activated RAW 264.7 cells with the IC50 values of 79.10, 44.34, 51.28, 33.54, 37.67, and 28.56 μM, respectively, compared to that of the positive control, dexamethasone, which showed IC50 value of 13.66 μM. The other isolates were inactive with IC50 values over 100 μM.

Four Undescribed compounds Isolated from the Aerial Parts of Phyllanthus cochinchinensis with Antimicrobial Activity and NO Production Inhibitory Activity in LPS Activated RAW 264.7 Cells

Four previously undescribed compounds named phyllancosides A and B (1 and 2), and phyllancochines A and B (3 and 4) together with ten known compounds (5-14) were isolated from the aerial parts of Phyllanthus cochinchinensis Spreng. Their chemical structures were elucidated on the basis of comprehensive analysis of IR, HR-ESI-MS, 1D and 2D NMR spectra. The absolute configurations of 1 and 2 were determined by electronic circular dichroism (ECD) spectra. Compounds 3, 4, and 10 showed antimicrobial activity against E. faecalis, S. aureus, and B. cereus with the MIC values in range of 32-256 μg/mL. Compound 11 inhibited E. faecalis and B. cereus, and 7 inhibited S. aureus with the MIC values in range of 64-128 μg/mL. In addition, compounds 1, 3, 4, 8, and 9 showed significantly NO production inhibitory activity in LPS activated RAW 264.7 cells with IC50 values ranging from 36.57 to 56.34 μM.

Undescribed Triterpenes from the Leaves of Syzygium myrsinifolium with Their α-Glucosidase and α-Amylase Inhibition Activity

Two undescribed triterpenes, syzyfolium A (1) and syzyfolium B (2), together with twelve known compounds, terminolic acid (3), actinidic acid (4), piscidinol A (5), threo-dihydroxydehydrodiconiferyl alcohol (6), lariciresinol-4-O-β-D-glucoside (7), icariol A2 (8), 14β,15β-dihydroxyklaineanone (9), garcimangosone D (10), (+)-catechin (11), myricetin-3-O-α-L-rhamnopyranoside (12), quercitrin (13), and 3, 4, 5-trimethoxyphenyl-(6'-O-galloyl)-O-β-D-glucopyranoside (14) were isolated from the leaves of Syzygium myrsinifolium. Their chemical structures were determined by IR, HR-ESI-MS, 1D and 2D NMR spectra. Compounds 3 and 4 inhibited significantly α-glucosidase with IC50 values of 23.99 and 36.84, respectively, and compounds 1 and 2 inhibited significantly α-amylase with IC50 values of 35.48 and 43.65 μM, respectively.

Four Steroidal Saponins from the Trunks of Dracaena cambodiana with Inhibition of NO Production in LPS Activated RAW264.7 Cells

Dracaena cambodiana Pierre ex Gagnep. is well known as a medicinal plant and widely distributed in Vietnam. Phytochemical investigation on the trunks of D. cambodiana lead to the isolation of four undescribed compounds (1-4) together with seven known ones (5-11). Their structures were determined to be pennogenin-24-yl-O-β-D-glucopyranoside (1), 17α-hydroxycambodianoside C (2), (25R)-27-hydroxypenogenin 3-O-α-L-rhamnopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (3), (3β,25R)-17α,22α-dihydroxy-furost-5-en-3-yl-O-α-L-rhamnopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (4), dracagenin A (5), 1-O-β-D-glucopyranosyl-2-hydroxy-4-allylbenzene (6), 1-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-2-hydroxy-allylbenzene (7), 2-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-1-hydroxy-allylbenzene (8), cinnamrutinoside A (9), icariside D1 (10), and seco-isolariciresinol 9-O-β-glucopyranoside (11) by extensive spectroscopic investigation, HR-ESI-MS, 1D and 2D NMR spectra. The anti-inflammatory activity of the isolated compounds was evaluated on macrophages. Compounds 1-6 significantly inhibited nitric oxide production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Among them, compound 1 showed the best inhibitory activity with an IC50 value of 8.90±0.56 μM.

Four New Steroidal Saponins from the Roots of Dracaena cambodiana with NO Production Inhibition Activity in LPS Activated RAW 264.7 Cells

Seven steroidal saponins including three new 16,23-cyclocholestanes (1-3) and one new pregane (4) were isolated from the roots of Dracaena cambodiana Pierre ex Gagnep. Their chemical structures were elucidated to be (23R,25R)-26-O-β-D-glucopyranosyl-16,23-cyclocholesta-5,17(20)-dien-22-one-3β,16α,26-triol-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-β-D-glucopyranoside (1), (23R,25R)-26-O-β-D-glucopyranosyl-16,23-cyclocholesta-5,17,20(22)-trien-3β,22,26-triol-3-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucopyranoside (2), (23R,25R)-16,23-cyclocholesta-5,16,20(22)-trien-3β,22,26-triol-3-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucopyranoside (3), 3β-[(O-α-L-rhamnopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-β-D-gluco-pyranosyl)oxy]-pregna-5,17(20)-diene-16-one-20-carboxylic acid 4''''-O-β-D-glucopyranosylisopentyl ester (4), cambodianoside A (5), diosbulbiside C (6), and diosbulbiside D (7), by IR, HR-ESI-MS, 1D and 2D NMR spectra. Compounds 1 and 4-7 inhibited nitric oxide (NO) production in lipopolysaccharide activated RAW 264.7 cells with IC50 values ranging from 19.03±1.84 to 67.92±3.81 μM, whereas compounds 2 and 3 were inactive with IC50 values over 100 μM.

Glycoside constituents of Camellia amplexicaulis and their α-glucosidase inhibitory activity

Four new glycosides, named amplexicosides A-D (1-4), and five known compounds: benzyl 2-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyloxy]-benzoate (5), benzyl 2-neohesperidosyloxy-6-hydroxybenzoate (6), chrysandroside A (7), chrysandroside B (8) and camelliquercetiside C (9) were isolated from the branches and leaves of Camellia amplexicaulis (Pit.) Cohen-Stuart. Their structures were elucidated using HR-ESI-MS and 1D- and 2D-NMR spectra and compared to reported NMR data. All of the isolated compounds were screened in an α-glucosidase assay. Compounds 4, 8, and 9 significantly inhibited α-glucosidase with respective IC50 values of 254.9 ± 4.2, 304.8 ± 11.9 and 228.1 ± 16.4 μM.

Three Undescribed Iridoid Derivatives Isolated from the Fruits of Vitex trifolia with Their Cytotoxic and Antimicrobial Activities

Vitex trifolia L. is a medicinal plant and widely distributed in the northern mountainous areas of Vietnam. Phytochemical study on the fruits of this plant led to the isolation of nine iridoid derivatives (1-9) including three undescribed compounds (1-3). Their structures were elucidated to be 3''-hydroxyscrophuloside A1 (1), 3''-hydroxycallicoside D (2), 2'-p-hydroxybenzoylaucubin (3), 6'-p-hydroxybenzoylmussaenosidic acid (4), nishindaside (5), agnuside (6), 10-O-vanilloylaucubin (7), 6'-O-p-hydroxybenzoyl-gardoside (8), and buddlejoside B (9) based on extensive analyses of HR-ESI-MS, 1D and 2D NMR spectra. Compounds 1, 2, 4, and 8 significantly posessed anti-barterial activity against Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa strains with MIC values in range of 16-64 μg/mL. At concentration of 20 μM, compounds 1-9 did not show cytotoxic effects against human lung cancer cells (PC9).

Undescribed 2,9-deoxyflavonoids and flavonol-diamide [3+2] adduct from the leaves of Aglaia odorata Lour. Inhibit nitric oxide production

Phytochemical study on the methanol extract of Aglaia odorata leaves resulted in the isolation of four previously undescribed compounds, including three 2,9-deoxyflavonoids and one flavonol-diamide [3 + 2] adduct, and 13 known compounds. The chemical structures of the four undescribed compounds were elucidated on the basis of their IR, HR-ESI-MS, 1D and 2D NMR, and ECD spectra. The results revealed an unprecedented 2,9-deoxyflavonoid framework, which was confirmed by TD-DFT, ECD, and GIAO 13C-NMR calculations using sorted training set methods. The 17 compounds were examined for their ability to inhibit NO production activity in cultured lipopolysaccharide-activated RAW264.7 cells with aglaodoratas A-C, odorine, and epi-odorine inhibiting NO production, with IC50 values in the range of 16.2-24.3 μM. The other investigated compounds had either weak or no activity.

New nitric oxide production inhibitors from Syzygium bullockii

Three undescribed triterpene glycosides syzybullosides A-C (1-3) along with fourteen known compounds were isolated from the leaves of Syzygium bullockii (Hance) Merr.& L.M. Perry, including six triterpene glycosides (1-6), four phenolics (7-9, 17), four megastigmanes (10-13), and three flavonoids (14-16). The structures of 1-17 were elucidated by extensive spectroscopic analysis, including IR, HR-ESI-MS, 1D and 2D NMR spectra. Compounds 1-10 and 12-17 inhibited nitric oxide (NO) production in lipopolysaccharide activated RAW264.7 cells with IC50 values ranging from 1.30 to 13.70 µM, lower than that of the positive control compound, L-NMMA (IC50 = 33.8 µM).

Undescribed Phenolic Glycosides from Syzygium attopeuense and Their Inhibition of Nitric Oxide Production

Four undescribed phenolic glycosides including three stilbene derivatives (1 and 3) and sodium salt of 3 (2), and a chalcone glycoside (4), together with thirteen known compounds (5-17) were isolated from the leaves of Syzygium attopeuense (Gagnep.) Merr. & L.M.Perry. Their chemical structures were elucidated to be (Z)-gaylussacin (1), 6''-O-galloylgaylussacin sodium salt (2), 6''-O-galloylgaylussacin (3), 4'-O-[β-D-glucopyranosyl-(1→6)-glucopyranosyl]oxy-2'-hydroxy-6'-methoxydihydrochalcone (4), gaylussacin (5), pinosilvin 3-O-β-D-glucopyranoside (6), myricetin-3-O-(2''-O-galloyl)-α-L-rhamnopyranoside (7), myricetin-3-O-(3''-O-galloyl)-α-L-rhamnopyranoside (8), myricetin-3-O-α-L-rhamnopyranoside (9), quercitrin (10), myricetin-3-O-β-D-glucopyranoside (11), myricetin-3-O-β-D-galactopyranoside (12), quercetin 3-O-α-L-arabinopyranoside (13), myricetin-3-O-2''-O-galloyl)-α-L-arabinopyranoside (14), (+)-gallocatechin (15), (-)-epigallocatechin (16), and 3,3',4'-trimethoxyellagic acid 4-O-β-D-glucopyranoside (17) by the analysis of HR-ESI-MS, 1D and 2D NMR spectra in comparison with the previously reported data. Compounds 1-3, 5, and 6 significant inhibition of NO production in LPS-activated RAW264.7 cells, with IC50 values ranging from 18.37±1.38 to 35.12±2.53 μM, compared to a positive control (dexamethasone) with an IC50 value of 15.37±1.42 μM.

Desmodinosides A-E: New Flavonoid C-glycosides from Desmodium heterocarpon var. stigosum with hepatoprotective and antifungal activity

Five new flavonoid C-glycosides named desmodinosides A-E (1-5) and one known compound, apigenin 6-C-β-d-xylopyranosyl-2''-O-β-D-glucopyranoside (6) have been isolated from the methanol extract of the aerial parts of Desmodium heterocarpon var. stigosum. These compounds were determined by 1D and 2D-NMR and HR-MS spectroscopies. The methanol extract of this plant, in particular, demonstrated hepatoprotection and antifungal inhibition. This extract has a remarkable hepatoprotection and activity-dose response with an EC50 of 43.07 μg/mL. The hepatoprotective effect on human liver hepatoma cells (HepG2) of the isolated flavonoid C-glycosides 1-6 was observed. Desmodinosides A-C (1-3) were found to exhibit moderate hepatoprotective activity on HepG2 cells. Of these, compound 2 showed the best hepatoprotective activity with an EC50 value of 74.12 μg/mL. While compounds 1 and 3 displayed EC50 values of 271.21 and 211.99 μg/mL, respectively. Quercetin, a positive control, also caused an EC50 value of 36.42 μg/mL. In addition to having hepatoprotective effect, the methanol extract had an inhibitory effect on the growth of oomycete; it inhibited Phytophthora infestans with IC50 of 13.3 μg/mL and IC90 of 78.7 μg/mL. The oomycete inhibition was directly attributed to compounds 5 and 6, which significantly inhibited P. infestans with IC50 values of 27.4 and 24.7 μg/mL, respectively. Both 5 and 6 and methanol extract were active against P. infestanse in a dose-dependent manner. Our study demonstrated for the first time the new flavonoid C-glycosides from D. heterocarpon var. stigosum and their novel pharmacological properties. The study findings also suggest the plant extract and its metabolites could be used as a new botanical source of bioactive compounds.

Four New Flavonoid C-Glycosides Isolated from Achyranthes aspera and Their Nitric Oxide Production Inhibitory Activities

A chemical study of the methanol extract of the aerial parts of Achyranthes aspera led to the isolation of four new flavonoid C-glycosides (1-4) along with eight known analogs (5-12). Their structures were elucidated by a combination of spectroscopic data analysis, HR-ESI-MS, 1D and 2D NMR spectra. All the isolates were evaluated their NO production inhibitory activity in LPS-activated RAW264.7 cells. Compounds 2, 4, and 8-11 showed significant inhibition with IC50 values ranging from 25.06 to 45.25 μM, compared to that of the positive control compound, L-NMMA, IC50 value of 32.24 μM, whereas the remaining compounds were weak inhibitory activity with IC50 values over 100 μM. This is the first report of 7 from Amaranthaceae family, and 11 from the genus Achyranthes.

Elsholblanosides A-D, Four New Oleuropeic Acid Derivatives Isolated from Elsholtzia blanda and Their Inhibition of NO Production in LPS-activated RAW264.7 Cells

Phytochemical investigation on the aerial parts of Elsholtzia blanda Benth. afforded four new oleuropeic acid derivatives (1-4), named as elsholblanosides A-D, respectively, together with 11 known compounds (5-15). Their structures were determined based on extensive analyses of HR-ESI-MS, 1D and 2D NMR, and ECD spectra. Compounds 1-4 and 14 showed moderate NO production inhibition in LPS-activated RAW264.7 cells with their IC50 values ranging from 23.2 to 86.33 μM, compared to that of the positive control compound, dexamethasone, IC50 value of 16.9 μM.

Phytochemical constituents from Elsholtzia ciliata (Thunb.) Hyl. and their nitric oxide production inhibitory activities

A new megastigmane glycoside, (3S,4R,7E)-megastigma-5,7-diene-9-one-3,4-diol 3-O-β-D-apiofuranosyl-(1→2)-β-D-glucopyranoside (1) and a new cyanogenic glycosyl derivative, (S)-2-(6'-O-R-rosmarinoyl-β-D-glucopyranosyloxy)-phenylacetonitrile (2) were isolated from the methanol extract of the Elsholtzia ciliata together with twelve known compounds, 1-O-β-D-glucopyranosyl-2-hydroxy-4-allylbenzene (3), citrusin C (4), 1,2-di-O-β-D-glucopyranosyl-4-allylbenzene (5), manglieside B (6), 4-allyl-2-hydroxyphenyl 1-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (7), (-)-isolariciresinol 3α-β-D-glucopyranoside (8), 7R,8R-threo-4,7,9-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-9'-O-β-D-glucopyranoside (9), 7R,8R-threo-4,7,9,9'-tetrahydroxy-3-methoxy-8-O-4'-neolignan-9'-O-β-D-glucopyranoside (10), cedrusin-4-O-β-D-glucopyranoside (11), icariside E3 (12), everlastoside L (13) and rosmarinic acid (14). Their chemical structures were elucidated on the basic of extensive 1D and 2D-NMR experiments, as well as their mass spectroscopic data. The absolute configurations of the compounds 1 and 2 were successfully indicated by both theoretical and calculated CD spectra. Compounds 3-7, 9 and 10 potential inhibited NO production in LPS-activated RAW264.7 cells with IC50 values of 6.71, 8.97, 12.38, 14.27, 16.13, 13.54, 16.27 µM, respectively, compared to that of the positive control of NG-monomethyl-L-arginine acetate (L-NMMA), IC50 = 32.51 µM.

Dimethylbutyrylated Dibenzocyclooctadiene Lignans from the Fruits of Schisandra cauliflora Inhibit NO Production in LPS-activated RAW264.7 Cells

From the fruits of Schisandra cauliflora, five new dimethylbutyrylated dibenzocyclooctadiene lignans, named schisandracaurin A-E, were isolated using separation and chromatographic techniques. Their structures were determined by extensive analyses of HR-ESI-MS, NMR, and ECD spectra. The schisandracaurin A-E  potentially inhibited NO production in LPS-activated RAW264.7 cells with their IC50 values from 21.4 to 30.3 μM.

New Isopropyl Chromone and Flavanone Glucoside Compounds from the Leaves of Syzygium cerasiforme (Blume) Merr. & L.M.Perry and Their Inhibition of Nitric Oxide Production

A new isopropyl chromone (1) and a new flavanone glucoside (2) together with eleven known compounds (3-13) were isolated from the leaves of Syzygium cerasiforme (Blume) Merr. & L.M.Perry. Their structures were elucidated as 5,7-dihydroxy-2-isopropyl-6,8-dimethyl-4H-chromen-4-one (1), 5,7-dihydroxyflavanone 7-O-β-D-(6''-O-galloylglucopyranoside) (2), strobopinin (3), demethoxymatteucinol (4), pinocembrin-7-O-β-D-glucopyranoside (5), (2S)-hydroxynaringenin-7-O-β-D-glucopyranoside (6), afzelin (7), quercetin (8), kaplanin (9), endoperoxide G3 (10), grasshopper (11), vomifoliol (12), litseagermacrane (13) by the analysis of HR-ESI-MS, NMR, and CD spectral data. Compounds 1, 2, 5, 6 and 10 inhibited NO production on LPS-activated RAW264.7 cells with IC50 values of 12.28±1.15, 8.52±1.62, 7.68±0.87, 9.67±0.57, and 6.69±0.34 μM, respectively, while the IC50 values of the other compounds ranging from 33.38±0.78 to 86.51±2.98 μM, compared to that of the positive control, NG -monomethyl-L-arginine acetate (L-NMMA) with an IC50 value of 32.50±1.00 μM.

Rhabdastrenones A-D from the sponge Rhabdastrella globostellata

Three new isomalabaricanes (1–3), a new α-pyrone derivative (4), together with four known isomalabaricane analogs rhabdastrellin G (5), isogeoditin A (6), stelliferin A (7), and (13E)-isogeoditin A (8) were isolated from the marine sponge Rhabdastrella globostellata. Their chemical structures were determined by HR-ESI-MS, 1D and 2D-NMR spectroscopic data analysis. The absolute configurations were identified by Mo₂(OAc)₄ induced ECD spectra and TD-DFT theoretical calculated ECD spectra. Compound 6 exhibited weak cytotoxic effects against HepG2 and SKMel2 cell lines with the IC₅₀ values of 7.53 ± 0.70 and 9.93 ± 0.95 μM, respectively.

Three new isomalabaricanes and a new α-pyrone derivative isolated from the sponge Rhabdastrella globostellata.

Four New Acyclic Diterpenes From Siegesbeckia orientalis

Four new acyclic diterpenes, siegetalises A-D (1-4), were isolated from the aerial parts of Siegesbeckia orientalis. Their chemical structures were elucidated by extensive analysis of high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance spectral data. The effects of the isolated compounds on the activity of xanthine oxidase were evaluated by the oxidative reaction with xanthine as a substrate. At a concentration of 50 µM, compounds 1-4 exhibited xanthine oxidase inhibitory activity at levels of 13.59% ± 0.51%, 19.64% ± 1.54%, 17.45% ± 1.26%, and 21.36% ± 1.40%, respectively.

Guaianolide sesquiterpenes and benzoate esters from the aerial parts of Siegesbeckia orientalis L. and their xanthine oxidase inhibitory activity

Five undescribed (four guaianolide sesquiterpenes and a benzoate ester derivative) and seven known compounds were isolated from the aerial parts of S. orientalis L. Their chemical structures were determined by extensive analysis of HR-ESI-MS and NMR spectroscopic methods. Absolute configurations were elucidated by experimental and TD-DFT calculated ECD spectra. Twelve isolated compounds exhibited potential xanthine oxidase inhibitory activity with IC₅₀ values ranging from 0.76 ± 0.17 μM to 31.80 ± 0.97 μM. Molecular docking studies predicted that the binding energies of all isolated compounds with xanthine oxidase were lower than that of the positive control allopurinol. Benzyl 2-hydroxy-6-O-β-D-glucopyranosylbenzoate and benzyl 2-methoxy-6-O-β-D-glucopyranosylbenzoate displayed not only the best docking score but also the highest in vitro xanthine oxidase inhibitory activity with IC₅₀ values of 0.76 ± 0.17 μM and 0.98 ± 0.26 μM, respectively.

Fish-borne trematode metacercariae detected in fish commonly used for raw consumption in Ninh Binh Province, Vietnam

Raw or undercooked fish dishes are the major sources of human infection of fishborne trematodes (FBT) and the situation of metacercarial infection in fish greatly affect the prevalence in humans, especially those fish that are commonly used for raw consumption. To investigate the situation of infection with metacercaria of FBT in fish often used to prepare raw fish dishes by local people to assess the risk of infection to humans in Ninh Binh province, Vietnam. 345 fish belonging to five species of freshwater and one species of brackish water fish were collected from fishermen or small-scale fish dealers in Kim Son and Yen Khanh districts, Ninh Binh province between May 2017 and May 2018. Metacercaria of FBT was discovered by pepsin and hydrochloric acid digestion techniques and identified by the morphological and molecular analysis. Among examined fish, 44.06% infected with FBT metacercaria and the highest prevalence was in Cyprinus carpio (86.54%), Ctenopharyngodon idellus (78.43%) and Hypophthalmichthys molitrix (66.67%) while Konosirus punctatus - the brackish water fish - were free from infection. Three species of FBT were found; namely Haplorchis pumilio (accounting for 99.84% of collected metacercariae), Haplorchis taichui and Clonorchis sinensis. The average density was 1.06 metacercariae per gram of freshwater fish and the highest number was of C. idellus (6.38 cysts/gram) followed by Cirrhinus molitorella and C. carpio. Results of the study show the high prevalence of infection of FBT metacercariae among freshwater fish often used to prepare raw fish dishes in Ninh Binh province. These findings suggest the need for greater awareness of the risk from raw fish dishes among public health authorities and people.

New lupane-type and ursane-type triterpene saponins from the leaves of Trevesia palmata

Three new triterpene saponins including two lupane-types and an ursane-type were isolated from the leaves of Trevesia palmata. Their structures were determined as 2α,3β,23-trihydroxylup-20(29)-en-28-oic acid 3-O-α-L-arabinopyranoside (1), 2α,3β,23-trihydroxylup-20(29)-en-28-oic acid 3-O-[α-L-arabinopyranoside]-28-O-[β-D-glucopyranosyl] ester (2), and 2α,3β,23-trihydroxyurs-12-en-28-oic acid 3-O-[α-L-arabinopyranoside]-28-O-[β-D-glucopyranosyl(1→2)-β-D-glucopyranosyl] ester (3) by analysis of their HR-ESI-MS, 1D and 2D NMR spectra. The 2α,3β,23-trioxygenated pentacyclic triterpenes were uncommonly found in the nature. At concentration of 100 µM, compounds 1-3 inhibited NO production in LPS activated BV2 cells with inhibitory rates of 17.4 ± 1.8%, 33.1 ± 1.2%, and 11.7 ± 2.2%, respectively. But, they did not significantly inhibit yeast α-glucosidase activity.

Two New Steroidal Alkaloid Saponins from the Whole Plants of Solanum nigrum

Two new steroidal alkaloid saponins, solanigrosides Q and R (1 and 2), together with four known compounds khasianine (3), solamargine (4), solasonine (5), and soladulcoside A (6) were isolated from the whole plants of Solanum nigrum. The structures of new compounds (1 and 2) were determined by interpretation of HR-ESI-MS, 1D and 2D NMR spectra, and chemical transformation. Compound 4 exhibited potent cytotoxic activity against MDA-MB-231, A549, Hep3B, PC3 human cancer cell lines with IC50 values of 1.86 ± 0.45, 2.24 ± 0.15, 0.78 ± 0.11, 5.13 ± 1.34 μM, respectively.

Rhabdaprovidines D–G, Four New 6,6,5-Tricyclic Terpenoids from the Vietnamese Sponge Rhabdastrella providentiae

Four new 6,6,5-tricyclic terpenoids, named rhabdaprovidines D-G (1–4), were isolated from the Vietnamese sponge Rhabdastrella providentiae. The structures of 1–4 were elucidated by extensive analysis of HR-ESI-MS and NMR spectroscopy. The absolute stereochemistry of compounds 3 and 4 were determined by both experimental and theoretical calculated circular dichroism (CD) spectra. Compounds 1, 2, and 4 contained trans-syn-trans 6,6,5-tricyclic nucleus meanwhile compound 3 possessed trans-syn-cis ring junction. Compound 4 displayed novel structure by the presence of five rings and nine chiral carbon centers in the isomalabaricane triterpene backbone.

New Acetylated Terpenoids from Sponge Rhabdastrella providentiae Inhibit NO Production in LPS Stimulated BV2 Cells

Three new acetylated terpenoids, rhabdaprovidines A-C (1-3), were isolated from the Vietnamese sponge Rhabdastrella providentiae. Their chemical structures were established by HR-ESI-MS, 1D and 2D-NMR experiments. These compounds share 6,6,5-tricyclic nucleus of isomalabaricane-type triterpene, the specific secondary constituents from Rhabdastrella species. Compounds 1-3 inhibited NO production in LPS stimulated BV2 cells with IC50 values of 20.4 ± 1.5, 17.5 ± 0.9, and 46.8 ± 2.3 μM, respectively.

Phenolic Components from the Aerial Parts of Agrimonia pilosa

Two new resorcinol derivatives, named agrimopilosides A and B (1 and 2), along with two known compounds, (2 S, 3 S)-aromadendrin 3-O-β-D-glucopyranoside (3), (2 S, 3 S)-glucodistylin (4) were isolated from the aerial parts of Agrimonia pilosa. Their chemical structures were determined by mean of HRMS, NMR, CD spectra, and as well as by comparison with the reported data. At concentration of 20 μM, compounds 1–4 modestly inhibited NO production in LPS-stimulated RAW264.7 cells, with the inhibitory rates in the range of 9.55–33.73%. None of them showed cytotoxicity toward HepG2, MCF-7, and SK-LU-1 human cancer cells by MTT assay.

Oleanane-type Saponins from Glochidion hirsutum and Their Cytotoxic Activities

Five new oleanane-type saponins, hirsutosides A - E, were isolated from the leaves of Glochidion hirsutum (Roxb.) Voigt. Their structures were elucidated as 21β-benzoyloxy-3β,16β,23,28-tetrahydroxyolean-12-ene 3-O-β-d-glucopyranoside (1), 21β-benzoyloxy-3β,16β,23,28-tetrahydroxyolean-12-ene 3-O-β-d-glucopyranosyl-(1 → 3)-β-d-glucopyranoside (2), 21β-benzoyloxy-3β,16β,23,28-tetrahydroxyolean-12-ene 3-O-6-acetyl-[β-d-glucopyranosyl-(1 → 3)]-β-d-glucopyranoside (3), 21β-benzoyloxy-3β,16β,23,28-tetrahydroxyolean-12-ene 3-O-β-d-glucopyranosyl-(1 → 3)-〈-l-arabinopyranoside (4), and 21β-benzoyloxy-3β,16β,23-trihydroxyolean-12-ene-28-al 3-O-β-d-glucopyranosyl-(1 → 3)-α-l-arabinopyranoside (5). All isolated compounds were evaluated for cytotoxic activities on four human cancer cell lines, HepG-2, A-549, MCF-7, and SW-626 using the SRB assay. Compounds 1, 2, 4, and 5 showed significant cytotoxic activities against all human cancer cell lines with IC₅₀ values ranging from 3.4 to 10.2 μm. Compound 3 containing acetyl group at glc C(6″) exhibited weak cytotoxic activity with IC₅₀ values ranging from 47.0 to 54.4 μm.

New Phenolic Glycosides from Physalis angulata

Two new phenolic glycosides, physangulosides A and B (1 and 2), were isolated from the whole plant of Physalis angulata. Their chemical structures were determined by mean of HR-ESI-MS, 1D, and 2D-NMR spectra. Both of the compounds showed weak protection against hydrogen peroxide induced hepatocytes damage.

New Phenolic Glycosides from Physalis angulata

Two new phenolic glycosides, physangulosides A and B (1 and 2), were isolated from the whole plant of Physalis angulata. Their chemical structures were determined by mean of HR-ESI-MS, lD, and 2D-NMR spectra. Both of the compounds showed weak protection against hydrogen peroxide induced hepatocytes damage.

Steroidal Glucosides from the Rhizomes of Tacca Chantrieri and Their Inhibitory Activities of NO Production in BV2 Cells

Two new steroidal glucosides, chantriolides D and E (1 and 2), along with four known compounds, chantriolide A (3), chantriolide B (4), chantriolide C (5), and (25 S)-spirost-5-en-3-ol 3- O-α-L-rhamnopyranosyl-(1→2)- O-[α-L-rhamnopyranosyl-(1→3)]-β-D-glucopyranoside (6) were isolated from the rhizomes of Tacca chantrieri. Their structures were determined by 1D and 2D NMR spectroscopic and HR-ESI-MS data, as well as by comparison with reported data. Compounds 1 and 2 were found to show strong inhibitory NO effect in BV2 cells, with IC50 values of 12.45 and 59.03 μM, respectively.

Steroidal Glucosides from the Rhizomes of Tacca chantrieri and Their Inhibitory Activities of NO Production in BV2 Cells

Two new steroidal glucosides, chantriolides D and E (1 and 2), along with four known compounds, chantriolide A (3), chantriolide B (4), chantriolide C (5), and (25S)-spirost-5-en-3-ol 3-O-α-L-rhamnopyranosyl-(1-->2)-O-[α-L-rhamnopyranosyl-(1-->3)]-β-D-glucopyranoside (6) were isolated from the rhizomes of Tacca chantrieri. Their structures were determined by 1D and 2D NMR spectroscopic and HR-ESI-MS data, as well as by comparison with reported data. Compounds 1 and 2 were found to show strong inhibitory NO effect in BV2 cells, with IC₅₀ values of 12.45 and 59.03 µM, respectively.

Cucurbitane-type triterpene glycosides from the fruits of Momordica charantia

Four new cucurbitane-type triterpene glycosides, charantosides D-G (1-4) were isolated from a methanol extract of Momordica charantia fruits. The structures of these compounds were determined by chemical and spectroscopic methods to be (19R)-5 beta,19-epoxy-25-methoxycucurbita-6,23-diene-3 beta,19-diol 3-O-beta-D-glucopyranoside, (19R)-5 beta, 19-epoxy-25-methoxycucurbita-6,23-diene-3 beta,19-diol 3-O-beta-D-allopyranoside, 7 beta-methoxycucurbita-5,23E,25-triene-3 beta-ol 3-O-beta-D-allopyranoside, and 3 beta,7 beta-dihydroxycucurbita-5,23E,25-triene- 19-al 3-O-beta-D-allopyranoside.

Cucurbitane-type Triterpene Glycosides from the Fruits of Momordica charantia

Four new cucurbitane- type triterpene glycosides, charantosides D-G (1–4) were isolated from a methanol extract of Momordica charantia fruits. The structures of these compounds were determined by chemical and spectroscopic methods to be (19 R)-5 β,19-epoxy-25-methoxycucurbita-6,23-diene-3 β,19-diol 3- O-β-D-glucopyranoside, (19 R)-5 β,19-epoxy-25-methoxycucurbita-6,23-diene-3 β,19-diol 3- O-β-D-allopyranoside, 7 β-methoxycucurbita-5,23 E,25-triene-3 β-ol 3- O-β-D-allopyranoside, and 3 β,7 β-dihydroxycucurbita-5,23 E,25-triene-19-al 3- O-β-D-allopyranoside.