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.

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, 18ß-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-ß-D-glucopyranoside (14), (+)-isolarisiresinol 3α-O-ß-D-glucopyranoside (15), and (-)-lyoniresinol 3α-O-ß-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-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.

Chemical constituents from the heterotrophic marine microalgae Aurantiochytrium sp. SC145 and their antimicrobial activities.

One new indol, N-methoxymethyltryptophol (1), one new phenolic, (2 R)-2-(4-hydroxyphenyl)ethyl 2-hydroxy-3-phenylpropanoate (2) and fifteen known compounds (3-17) were isolated from the methanol extract of the fermentation of marine microalgae Aurantiochytrium sp. SC145. Their structures were elucidated by 1D-, 2D-NMR spectroscopic analysis, HR-ESI-MS, quantum chemical calculation methods and by comparing their NMR data with those reported in the literature. All compounds were evaluated for their antimicrobial activities against microorganisms. Compounds 2, 3 and 11 significantly exhibited antimicrobial activities on all tested Gram-(+), Gram-(-) bacteria and the yeast C. albicans with MIC values ranging from 32 to 256 µg/mL.

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-ß-D-glucopyranosyl-16,23-cyclocholesta-5,17(20)-dien-22-one-3ß,16α,26-triol-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-ß-D-glucopyranoside (1), (23R,25R)-26-O-ß-D-glucopyranosyl-16,23-cyclocholesta-5,17,20(22)-trien-3ß,22,26-triol-3-O-α-L-rhamnopyranosyl-(1→3)-ß-D-glucopyranoside (2), (23R,25R)-16,23-cyclocholesta-5,16,20(22)-trien-3ß,22,26-triol-3-O-α-L-rhamnopyranosyl-(1→3)-ß-D-glucopyranoside (3), 3ß-[(O-α-L-rhamnopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-ß-D-gluco-pyranosyl)oxy]-pregna-5,17(20)-diene-16-one-20-carboxylic acid 4''''-O-ß-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.

Discovery of Four New Compounds from Macropanax membranifolius and Their Cytotoxic Activity.

A phytochemical investigation of the methanolic extract of the Macropanax membranifolius C.B. Shang leaves led to the isolation of three new flavans, (2R,3R)-4'-O-methylcatechin 5-O-ß-D-glucopyranoside (1), (2S,3S)-4'-O-methylcatechin 5-O-ß-D-glucopyranoside (2), (2S,3R)-4'-O-methylcatechin 5-O-ß-D-glucopyranoside (3), one new triterpene glycoside 3-O-ß-D-xylopyranosyl-(1→6)-[ß-D-xylopyranosyl-(1→2)]-ß-D-glucopyranosyl-oleanolic acid 28-O-ß-D-glucopyranoside (4), together with nine known compounds (5-13). Their chemical structures were elucidated based on HR-ESI-MS, NMR spectroscopic data. The absolute configurations of compounds 1-3 were established by electronic circular dichroism (ECD) spectra. At concentration of 20 µM, compounds 1-13 showed the percentages of dead cell in the range of 2.14 % to 33.61 % against KB, HepG2, HL60, P388, HT29, and MCF7 cancerous cell lines by SRB assay.

Kadsindutalignans A-C: three new dibenzocyclooctadiene lignans from Kasura induta A.C.Sm. and their nitric oxide production inhibitory activities.

Phytochemical study on the methanol extract of the stems and leaves of Kadsura induta led to the isolation of six dibenzocyclooctadiene lignans, including three new compounds named kadsindutalignans A-C (1-3), and three known ones, heteroclitalignan B (4), kadsuphilin C (5) and kadsulignan E (6). Their structures were elucidated based on extensive spectroscopic analyses, including HRESIMS, 1D- (1H NMR and 13C NMR), 2D-NMR (HSQC, HMBC, 1H-1H COSY and NOESY), and experimental circular dichroism (CD) spectra. All the isolates inhibited NO production in LPS-activated RAW264.7 cells with IC50 values in the range from 5.67 ± 0.54 µM to 38.19 ± 2.03 µM, compared to that of the positive control of NG-monomethyl-L-arginine acetate (L-NMMA) with an IC50 value of 8.90 ± 0.48 µM. Interestingly, the new compound 2 showed potential inhibition of NO production with an IC50 value of 5.67 ± 0.54 µM, which was higher than that of the positive control.

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.

Iridoid glycosides link with phenylpropanoids from Rehmannia glutinosa.

Two new iridoid glycosides link with phenylpropanoids, rehmanniosides G (1) and H (2) along with 11 known compounds, 6-O-(E)-caffeoylajugol (3), 6-O-(E)-feruloylajugol (4), verbasoside (5), jionoside C (6), acteoside (7), leucosceptoside A (8), brachynoside (9), jionoside B1 (10), jionoside A1 (11), isoacteoside (12) and isomartynoside (13) were isolated from the roots of Rehmannia glutinosa (Gaertn.) DC. Their chemical structures were elucidated on the basis of extensive spectroscopic methods, including 1D, 2D NMR and mass spectra. Compounds 7 - 11 showed significant inhibitory α-glucosidase with IC50 values ranging from 261.4 to 408.7 µM (acarbose, IC50 of 204.2 ± 19.9 µM).[Formula: see text].

Four new aaptamine alkaloids from marine sponge Aaptos aaptos.

Four new aaptamine alkaloids, named as 9-methoxy-N-demethylaaptanone (1), 3,5-dicarbomethoxy-1,​6-​naphthyridine (2), aaptosvanphongs A and B (3 and 4), and three known aaptamine alkaloids as 2-methoxy-3-oxoaaptamine (5), 8,9,9-trimethoxy-9H-benzo[de][1,6]-naphthyridine (6), and demethyl(oxy)aaptamine (7) were isolated from the sponge Aaptos by various chromatographic methods. Their structures were established by extensive spectroscopic analyses (HR-ESI-MS, 1 D and 2 D NMR) and by comparison of the spectral data with those reported in the literature. Compounds 1-7 significantly showed cytotoxic effects against SK-LU-1, MCF-7, HepG2, and SK-Mel-2 cell lines with IC50 values in range from 7.7 ± 0.8 to 51.4 ± 1.8 µM. Among them, compound 7 exhibited the most cytotoxic activity with corresponding IC50 values of 9.2 ± 1.0, 7.8 ± 0.6, 8.4 ± 0.8, and 7.7 ± 0.8 µM.[Formula: see text].

Dihydrostilbene glycosides from Camellia sinensis var. assamica and their cytotoxic activity.

Three undescribed dihydrostilbene glycosides, 3,5-dihydroxyldihydrostilbene 4'-O-[6''-O-(4'''-hydroxylbenzoyl)]-ß-D-glucopyranoside (1), 3,5-dihydroxyldihydrostilbene 4'-O-(6''-O-galloyl)-ß-D-glucopyranoside (2), and 3,5-dihydroxyldihydrostilbene 4'-O-[6''-O-(3''',4'''-dimethoxyl)galloyl]-ß-D-glucopyranoside (3), and seven known compounds, kaempferol 3-O-ß-D-glucopyranoside (4), isoquercitrin (5), kaempferol 3-O-α-L-rhamnoside (6), quercitrin (7), (6S,9R)-roseoside (8), (-)-epicatechin 3-O-gallate (9), and (-)-epigallocatechin 3-O-gallate (10) have been isolated from the methanol extract of the leaves of Camellia sinensis var. assamica (J.W.Mast.) Kitam. (synnonym of Camellia assamica (Mast.) H.T.Chang) (Theaceae). Their structures were elucidated by spectroscopic methods (1 D-, 2 D-NMR) and mass spectra. All compounds were evaluated for cytotoxic activity against human oral cancer (CAL27) and human breast cancer (MDAMB231) cell lines. Compound 10 showed significant cytotoxic activity against CAL27 and MDAMB231 cell lines with IC50 values of 9.78 ± 0.25 and 3.27 ± 0.18 µM, respectively, compared to those of positive control, capecitabine (IC50 values of 8.20 ± 0.75 and 5.20 ± 0.89 µM).

Macrocyclic bis-quinolizidine alkaloids from Xestospongia muta.

A new stereoisomer Meso-araguspongine C together with nine reported macrocyclic bis-quinolizidine alkaloids araguspongines A, C, E, L, N-P, petrosin, and petrosin A were isolated from marine sponge Xestospongia muta. Stereochemistry of meso-araguspongine C (2) and araguspongines N-P (3-5) were established by their NMR data and conformational analyses. Both araguspongine C (1) and meso-araguspongine C (2) exhibited great cytotoxic activity towards HepG-2, HL-60, LU-1, MCF-7, and SK-Mel-2 human cancer cells (IC50 in the range of 0.43-1.02 µM). At a concentration of 20 µM, isolated compounds (1-10) also showed modest inhibitory effects (from 7.6 to 40.8%) on the NO production in LPS activated RAW264.7 macrophages.

Naphtoquinones and Sesquiterpene Cyclopentenones from the Sponge Smenospongia cerebriformis with Their Cytotoxic Activity.

Two new naphtoquinones (smenocerones A and B, 1 and 2) and four known sesquiterpene cyclopentenones (dactylospongenones A-D, 3-6) were isolated from sponge Smenospongia cerebriformis living in the Eastern Sea of Vietnam. Their chemical structures were determined by high resolution electrospray ionization (HR-ESI)-MS, NMR spectroscopic analysis, and in comparison with the reported data. The chiroptical properties of compounds 3-6 were examined by experiment and theoretical calculation of circular dichroism (CD) spectra to prove their absolute configurations. Compound 2 significantly exhibited cytotoxic activity towards lung carcinoma (LU-1), hepatocellular carcinoma (HepG-2), promyelocytic leukemia (HL-60), breast carcinoma (MCF-7), and melanoma (SK-Mel-2) human cancer cells with IC50 values of 5.5±0.8, 3.2±0.2, 4.0±0.7, 4.1±0.8, and 5.7±1.1 µg/mL, respectively.

Bis-sesquiterpene from the Marine Sponge Dysidea fragilis.

Two new sesquiterpenes and one new bis-sesquiterpene, named dysinidins C-E (1-3) along with three known sterols, dysideasterol F, 9α,l lα-epoxycholest-7-en-3ß,5α,6α-triol, and 9α,11α-epoxycholest-7-en-3ß,5α,6α,19-tetrol 6-acetate (4-6) were isolated from the Vietnamese marine sponge Dysidea fragilis (Montagu, 1814). Their structures were determined by 1D- and 2D-NMR spectroscopies and HR-ESI-MS, as well as by comparison with reported literature data. Compounds 4-6 were found to inhibit eight human cancer cell lines (KB, LU-1, HL-60, LNCaP, SK-Mel-2, HepG-2, MCF-7, and PC-3), with IC50 values ranging from 7.3 to 31.5 µM.

Two New Compounds from the Leaves of Glochidion obliquum.

Using combined chromatographic methods, two new compounds, 6ß,9ß:9,13-diepoxymegastig-4-en-3ß-ol (1), 5a,6a-epoxy D:C-friedoolean-8-en-3ß-ol (2) were isolated from the methanol extract of the leaves of Glochidion obliquum Decne. Their structures were elucidated by 1D- and 2D-NMR spectra and in comparison with those reported in the literature.

Tirucallane Glycoside from the Leaves of Antidesma bunius and Inhibitory NO Production in BV2 Cells and RAW264.7 Macrophages.

One new tirucallane-type triterpene glycoside, antidesoside (1), along with two biflavones, podocarpusflavone A (2) and amentoflavone (3) and two megastigmane glycosides, byzantionoside B (4), and (6S,9R)-roseoside (5) were isolated from the methanol extract of Antidesma bunius leaves. Their structures were determined by spectroscopic methods and in comparison with the published data. Compounds 1 - 3 were found to show strong inhibitory effect of NO production in BV2.cells and RAW264.7 macrophages LPS-stimulated, with IC50 values ranging from 8.5 to 26.9 µM.

Sesquiterpenes from the Vietnamese Marine Sponge Dysidea fragilis.

Two new sesquiterpenes, named dysinidins A-B (3, 4) along with two known sesquiterpenes, furodysinin lactone (1) and O-methyl urodysinin lactone (2), were isolated from the Vietnamese marine sponge Dysidea fragilis. Their structures were determined by ID- and 2D-NMR spectroscopies and HR ESI MS, as well as by comparison with reported literature data. None of compounds showed inhibitory growth of human lung cancer cell lines, A-549 and H-1975 (IC50 > 30 µM).

Chemical constituents of the Annona glabra fruit and their cytotoxic activity.

CONTEXT: Traditional Chinese medicines have attracted increasing interest as potential sources of novel drugs with a wide range of biological and pharmacological activities. Annona glabra Linn (Annonaceae) is used in traditional medicine as an anticancer drug. Phytochemical investigation of this plant led to the isolation of acetogenins, ent-kauranes, peptides, and alkaloids. In addition, compounds exhibited anticancer, anti-HIV-reserve, and antimalaria. OBJECTIVE: Isolation, structure determination, and cytotoxic activity evaluation of compounds from the methanol extract from A. glabra fruits. MATERIALS AND METHODS: Using chromatographic methods to isolate compounds from the A. glabra methanol extract. The cytotoxic activity of compounds was evaluated by a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, compounds which showed significant cytotoxic activity were chosen for further study apoptosis characteristics. RESULTS: One new, (2E,4E,1'R,3'S,5'R,6'S)-dihydrophaseic acid 1,3'-di-O-ß-d-glucopyranoside, and eight known compounds, (2E,4E,1'R,3'S,5'R,6'S)-dihydrophaseic acid 3'-O-ß-d-glucopyranoside (2), icariside D2 (3), icariside D2 6'-O-ß-d-xylopyranoside (4), 3,4-dimethoxyphenyl O-ß-d-glucopyranoside (5), 3,4-dihydroxybenzoic acid (6), blumenol A (7), cucumegastigmane I (8), and icariside B1 (9), were isolated from the fruits of A. glabra. Icariside D2 (3) was found to show significant cytotoxic activity on the HL-60 cell line with the IC50 value of 9.0 ± 1.0 µM and did not show cytotoxic activity on the Hel-299 normal cell line. The further test indicated that compound 3 induced apoptosis via alteration of expression of apoptosis-related proteins and decreased phosphorylation of AKT in HL-60 cells. DISCUSSION AND CONCLUSION: The results suggested that the constituents from A. glabra may contain effective compounds which can be used as anticancer agents.