Five New Furostanol Glycosides from the Fruits of Tribulus terrestris with NO Production Inhibitory Activity.

Eight furostanol glycosides including five undescribed compounds, named tribufurostanosides A-E (1-5), and three known ones (6-8) were isolated from the fruits of Tribulus terrestris L. Their chemical structures were determined by the IR, HR-ESI-MS, 1D-, and 2D-NMR spectra. Furostanols 1-8 significantly inhibited nitric oxide production in LPS activated RAW 264.7 cells with IC50 values ranging from 14.2 to 64.7 µM, compared to that of the positive control compound, dexamethazone (IC50 13.6 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-ß-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.

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.

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-ß-D-glucopyranosyl-(1 → 6)-ß-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (1), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (2), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyluncargenin C 28-O-ß-D-glucopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (3), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosylhederagenin 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (4), 3-O-ß-D-glucopyranosylarjunolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (5), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß- D-glucopyranosyl-6ß,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (6), 3-O-ß-D-glucopyranosyl-6ß,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (7), asiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (8), and 3-O-ß-D-glucopyranosylasiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-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.

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.

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.

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-ß-D-glucoside (7), icariol A2 (8), 14ß,15ß-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-ß-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.

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-[ß-D-glucopyranosyl-(1→6)-ß-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.

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-ß-D-glucopyranoside (1), 17α-hydroxycambodianoside C (2), (25R)-27-hydroxypenogenin 3-O-α-L-rhamnopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-ß-D-glucopyranoside (3), (3ß,25R)-17α,22α-dihydroxy-furost-5-en-3-yl-O-α-L-rhamnopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-ß-D-glucopyranoside (4), dracagenin A (5), 1-O-ß-D-glucopyranosyl-2-hydroxy-4-allylbenzene (6), 1-O-α-L-rhamnopyranosyl-(1→6)-ß-D-glucopyranosyl-2-hydroxy-allylbenzene (7), 2-O-α-L-rhamnopyranosyl-(1→6)-ß-D-glucopyranosyl-1-hydroxy-allylbenzene (8), cinnamrutinoside A (9), icariside D1 (10), and seco-isolariciresinol 9-O-ß-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 Stilbene Derivatives Isolated from Gnetum latifolium var. funiculare Markgr. and Their Inhibition of NO Production in LPS-activated RAW264.7 Cells.

Gnetum latifolium var. funiculare Markgr. is a medicinal plant and widely distributed in mountainous areas of Vietnam. Phytochemical investigation on the trunks of this plant afforded eight stilbene derivatives (1-8) including for new compounds (1-4). Their structures were determined based on extensive analyses of HR-ESI-MS, 1D and 2D NMR spectra. Among the isolates, compounds 1-3 showed moderate NO production inhibition in LPS-activated RAW264.7 cells with the IC50 values ranging from 46.81 to 68.10 µM, compounds 4 and 6 showed weak effects with the IC50 values of 96.57 and 79.46 µM, respectively, compared to that of the positive control compound, dexamethasone (IC50 14.20 µM).

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.

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-ß-D-apiofuranosyl-(1→2)-ß-D-glucopyranoside (1) and a new cyanogenic glycosyl derivative, (S)-2-(6'-O-R-rosmarinoyl-ß-D-glucopyranosyloxy)-phenylacetonitrile (2) were isolated from the methanol extract of the Elsholtzia ciliata together with twelve known compounds, 1-O-ß-D-glucopyranosyl-2-hydroxy-4-allylbenzene (3), citrusin C (4), 1,2-di-O-ß-D-glucopyranosyl-4-allylbenzene (5), manglieside B (6), 4-allyl-2-hydroxyphenyl 1-O-ß-D-apiofuranosyl-(1→6)-ß-D-glucopyranoside (7), (-)-isolariciresinol 3α-ß-D-glucopyranoside (8), 7R,8R-threo-4,7,9-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-9'-O-ß-D-glucopyranoside (9), 7R,8R-threo-4,7,9,9'-tetrahydroxy-3-methoxy-8-O-4'-neolignan-9'-O-ß-D-glucopyranoside (10), cedrusin-4-O-ß-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.

New dibenzocyclooctadiene lignans from Kadsura induta with their anti-inflammatory activity.

Five new dibenzocyclooctadiene lignans, named kadsuindutains A-E (1-5), and three known ones schizanrin F (6), schizanrin O (7), and schisantherin J (8) were isolated from the stems of Kadsura induta. Their structures were determined by analyses of HR-ESI-MS, NMR, and ECD spectra. Compounds 1-5 contain a 2',4'-dioxygenated-2',3'-dimethylbutyryl moiety which is rarely reported for dibenzocyclooctadiene lignans. Molecular docking predicted that compounds 1-8 displayed good binding affinity to the active site of iNOS and TNF-α proteins but unstable binding to the active site of COX-2 protein. Additionally, in vitro experiments showed that compounds 1-8 inhibited NO production in LPS-activated RAW264.7 cells with IC50 values from 10.7 µM to 34.0 µM, compared to the positive control L-NMMA (IC50 = 31.2 µM).

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-ß-D-glucopyranosylbenzoate and benzyl 2-methoxy-6-O-ß-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.