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As part of an ongoing search for new protein tyrosine phosphatase 1B inhibitors and glucose uptake stimulators from nature, a new coumarin, selaginolide A (1) and four known isoflavones (2‒5) were isolated from the ethanol extract of a Vietnamese medicinal plant Selaginella rolandi-principis. The chemical structures of the isolates were elucidated by extensive analysis of spectroscopic and physicochemical data. Compounds 3‒5 have been identified from Selaginella genus for the first time. The antidiabetic properties of the isolates (1‒5) were investigated using in vitro assay on 2-NBDG uptake in 3T3-L1 adipocytes and against PTP1B and α-glucosidase enzyme activities as well. Compounds 1 exhibited the most potency with inhibitory IC50 values of 7.40 ± 0.28 and 7.52 ± 0.37 µM against PTP1B and α-glucosidase, respectively. Compounds 3 and 5 possessed potential inhibitions on PTP1B enzyme with IC50 values of 23.02 ± 1.29 and 11.08 ± 0.92 µM and moderate inhibitions on α-glucosidase with IC50 values of 36.47 ± 1.87 and 55.73 ± 2.58 µM, respectively. Compounds 2 and 4 showed weak PTP1B inhibitory activity (IC50 > 30 µM) but displayed remarkable α-glucosidase inhibition with IC50 values of 3.39 ± 0.87 and 9.72 ± 0.62 µM, respectively. Furthermore, ursolic acid as a positive control (IC50 3.42 ± 0.26 µM) and compounds 1 and 5 acted as mixed-competitive inhibitors against PTP1B enzyme with Ki values of 6.46, 10.28, and 15.01 µM, respectively. In addition, compounds 1 and 5 also showed potent stimulatory effects on 2-NBDG uptake at a concentration of 10 µM. The obtained result might suggest the potential of new coumarin (1) as a new type of natural PTP1B and α-glucosidase inhibitor for further research and development of antidiabetic and obese agents. Graphic abstract

Two new xanthones delpyxanthone A (1) and delpyxanthone B (3), together with four known ones, gerontoxanthone I (2), α-mangostin (4), cowanin (5) and cowanol (6) were isolated from the stem bark of...

A new oxoaporphine alkaloid, (−)-(6aR,7R)-N-acetylnorushinsunine (1) together with eight known compounds (2–9) had been isolated from the aerial part of Vietnamese Piper hymenophyllum Miq., Piperaceae. The chemical structures of 1–9 were established mainly by spectroscopic, spectrometric, and chiroptical spectra. Their anti-inflammatory activity was evaluated against lipopolysaccharides-induced nitric oxide production in RAW264.7 cells in vitro. Among them, compounds 2–4 showed significant inhibitory activities against the lipopolysaccharide-induced nitric oxide production in RAW264.7 cells with IC50 values of 7.2, 9.3, and 4.5 μM, respectively. In addition, compounds 2 and 4 suppressed both lipopolysaccharides-induced cyclooxygenase-2 and inducible nitric oxide synthase expressions. These results proposed that Piper hymenophyllum and its constituents may exert anti-inflammatory effects.

Seven pimarane diterpenes (1–7) were isolated from Orthosiphon stamineus Benth. by assay-guided isolation. All of the isolates possessed a 2-deoxy-2-((7-nitro-2,1,3-benzoxadiazol-4-yl)amino)-d-glucose uptake effect in 3T3-L1 adipocytes at concentrations of 5 and 10 ?M. Most of them showed potent inhibition against protein tyrosine phosphatase 1B with IC50 values ranging from 0.33 to 9.84 ?M. In the kinetic study, all inhibition types were exposed for the examined potencies, including mixed-competitive (1), non-competitives (3 and 5), competitive (6), and uncompetitive (7). The results suggested that O. stamineus and its pimarane diterpenes might exert the hypoglycemic effect via the insulin signaling pathway targeting inhibition of protein tyrosine phosphatase 1B (PTP1B) activity. The results suggest that these active constituents from O. stamineus may be the potential natural products for the development of anti-hypoglycemic agents.

Peltophorum pterocarpum is regarded as one of the most important medicinal plants in the traditional medicine system of Vietnam. However, scientific evidence for the antioxidant effects against lipid peroxidation and the potential effects in cancer of this plant are lacking. In our experiments, 70% ethanolic extracts of P. pterocarpum leaves (LPP) and stem bark (SPP) were evaluated for their low-density lipoprotein (LDL) oxidation and cytotoxic activity against cancer cell lines. Both LPP and SPP inhibited Cu2+-mediated LDL by increasing the lag time of conjugated diene formation and inhibiting the generation of thiobarbituric acid reactive substances (TBARS) in a dose-dependent manner. In cancer cells, LPP and SPP triggered the most potent cytotoxic effects against human leukemia cells, CRF-SBA and HL-60, with half-maximal inhibitory concentration (IC50) values ranging from 118.5 to 157.2 &micro, g/mL. SPP exhibited significant cytotoxicity against MIA PACA2, A549, and KG cell lines with IC50 values of 167.5, 244.1 and 255.0 &micro, g/mL, respectively. Meanwhile, LPP showed cytotoxic activity against KG with an IC50 value of 228.1 &micro, g/mL. SPP mediated cytotoxicity in HL-60 and CCRF-SBA cells through the activation of the apoptosis pathway, including the activation of caspases 3, and 9 and poly (ADP-ribose) polymerase (PARP). These results suggested that SPP may prevent the development and progression of atherosclerosis and leukemia in humans.

This study reports the anti-inflammatory activity-guided fractionation of the aerial part of Piper bavinum C. CD. (Piperaceae) that led to the isolation of eight secondary metabolites (1–8). The chemical structures of 1–8 were established mainly by NMR and mass spectra. Compound 5 was isolated from P. bavinum for the first time. All the isolated compounds were evaluated against LPS-induced NO production in macrophage RAW 264.7 cells in vitro. Among them, compound 4 showed the most potent inhibitory activity against the LPS-induced NO production with an IC50 value of 5.2 μM followed by compound 5 that inhibited NO production with an IC50 value of 13.5 μM. In the protein levels, compound 4 suppressed LPS-induced COX-2 and iNOS expressions in a dose-dependent manner. The results suggested that P. bavinum and its constituents might exert anti-inflammatory effects.

Seven pimarane diterpenes (1&ndash, 7) were isolated from Orthosiphon stamineus Benth. by assay-guided isolation. All of the isolates possessed a 2-deoxy-2-((7-nitro-2,1,3-benzoxadiazol-4-yl)amino)-d-glucose uptake effect in 3T3-L1 adipocytes at concentrations of 5 and 10 &mu, M. Most of them showed potent inhibition against protein tyrosine phosphatase 1B with IC50 values ranging from 0.33 to 9.84 &mu, M. In the kinetic study, all inhibition types were exposed for the examined potencies, including mixed-competitive (1), non-competitives (3 and 5), competitive (6), and uncompetitive (7). The results suggested that O. stamineus and its pimarane diterpenes might exert the hypoglycemic effect via the insulin signaling pathway targeting inhibition of protein tyrosine phosphatase 1B (PTP1B) activity.

Cassaine diterpenoids as erythrofordins A-C (1–3), pseudo-erythrosuamin (4), and erythrofordin U (5) isolated from the leaves of Vietnamese Erythrophleum fordii Oliver were tested cytotoxic activity against human leukemia cancer cells. The results showed that these metabolites exhibited dose-dependent cytotoxicity against human leukemia HL-60 and KG cells with IC50 values ranging from 15.2 ± 1.5 to 42.2 ± 3.6 µM. Treatment with erythrofordin B led to the apoptosis of HL-60 and KG cells due to the activation of caspase 3, caspase 9, and poly (ADP-ribose) polymerase (PARP). Erythrofordin B significantly increased Bak protein expression, but downregulated the anti-apoptotic protein Bcl-2, in HL-60 cells. In silico results demonstrated that erythrofordin B can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of −7.36 and −10.76 kcal/mol, respectively. These results indicated that the leaves of Vietnamese E. fordii, which contain cassaine diterpenoids, can induce the apoptosis of human leukemia cancer cells.

Two new naphthalene glycosides, morinlongosides A and B (1, 2) and a new iridoid glycoside, morinlongoside C (3), together with four known ones, geniposidic acid (4), (3R)-3-O-[β-D-xylopyranosyl-(1→6)-β-D-glucopyranosyl]-l-octen-3-ol (5), lucidin-3-O-β-primeveroside (6), and morindone-6-O-β-gentiobioside (7), were isolated from the roots of Morinda longissima Y. Z. RUAN. The structures of all isolated compounds (1-7) were elucidated on the basis of spectroscopic data (high resolution (HR)-MS, one and two dimensional (1/2D)-NMR).

A new oxygenated spiroketone, isodonspiroketone (1), and 4 known ones (2-5) were isolated from the whole plant of Isodon ternifolius (D.Don) Kudô. The structure of isodonspiroketone (1) was determined by nuclear magnetic resonance, mass spectroscopy, and circular dichroism spectral data. Compound 3 has not been previously isolated from I. ternifolius. Their cytotoxic activities were evaluated against A549, HepG2, and MDA-MB-231 cancer cell lines in vitro. New compound (isodonspiroketone, 1) showed moderate cytotoxic activities against A549, HepG2, and MDA-MB-231 cancer cell lines with half-maximal inhibitory concentration values of 23.84 ± 2.73, 27.77 ± 3.01, and 17.26 ± 1.61 μM, respectively; meanwhile, the others were inactive.

Ten active principles (compounds 1-10) have been isolated following protein tyrosine phosphatase 1B (PTP1B) assay-guided fractionation of the methanol extract of the root of Polygonum cuspidatum. The chemical structures of the compounds were characterized mainly by nuclear magnetic resonance (NMR) spectroscopic and physicochemical data. This is the first time that 9,10-anthraquinones (compounds 5-6) have been isolated from P. cuspidatum, and this is the first record of compound 9 from the genus Polygonum. Except for compound 4, all the isolates showed potential inhibitory activity against PTP1B with half-maximal inhibitory concentration IC50 values ranging from 6.3 to 28.9 µM. Furthermore, a kinetic study indicated mixed-competitive inhibition with PTP1B for compounds 2 and 9 and noncompetitive inhibition for compounds 3 and 6. In addition, compounds 2, 3, 6, and 9 also induced the 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl) amino]-d-glucose uptake stimulation in 3T3-L1 adipocytes at concentrations of 10 and 5 µM. Taken together, the results reveal that P. cuspidatum could be a new source of natural compounds for further research and development of antidiabetic agents.

Cassaine diterpenoids amides from the stem bark of Vietnamese Erythrophleum fordii Oliver were screened for their cytotoxic activity against human cancer cells. The cell proliferation assay results showed that, among the active compounds, 3&beta, acetyl-nor-erythrophlamide (3AEP) exhibited the most potential cytotoxicity against human leukemia HL-60 and KG cells with IC50 values of 12.0 &plusmn, 1.2 and 18.1 &plusmn, 2.7 &micro, M, respectively. Treatment of 3AEP resulted in the apoptosis of HL-60 cells via the activation of caspase 3, and poly (ADP-ribose) polymerase (PARP). Molecular docking in silico results showed that the 3AEP can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of &minus, 7.51 and &minus, 9.63 kcal/mol respectively. These results indicated that the stem bark of Vietnamese E. fordii and its cassaine diterpenoid amides may be useful in the apoptosis induction of human leukemia cancer cells.

In our preliminary screening study on the protein tyrosine phosphatase 1B (PTP1B) inhibitory and cytotoxic activities, an ethyl acetate soluble fraction of the aerial part of Orthosiphon stamineus Benth. was found to inhibit PTP1B activity. Thus, based on assay-guided isolation of this active fraction, ten compounds (1-10) were purified and evaluated for their inhibitory effects on PTP1B and their growth inhibition on MCF7, tamoxifen-resistant MCF7 (MCF7/TAMR), and MDA-MB-231 human breast cancer cell lines. Among the isolates, compounds 5, 6, 9, and 10 showed potencies against PTP1B with IC50 values of 9.76, 10.12, 6.88, and 8.92 μM, respectively, followed by compounds 1 and 4 with IC50 values of 16.92 and 22.25 μM. Kinetic study showed that the active compounds (1, 5, 9, and 10) possessed mixed-competitive inhibition, which was similar to the positive control (ursolic acid, IC50 value of 3.42 μM, mixed-competitive). The others showed noncompetitive inhibition (4 and 6). In addition, all these active compounds (1, 4-6, and 9-10) displayed growth inhibition on three cancer cell lines, especially the most PTP1B inhibitory flavanones (9 and 10) exhibited comparable inhibitory effects on MCF7, MCF7/TAMR, and MDA-MB-231 cancer cells (IC50 values of 11.5 and 15.4, 8.9 and 10.5, and 17.6 and 21.3 μM, respectively) with tamoxifen, the positive control used in this assay (IC50 values of 11.9, 12.1, and 12.7 μM, respectively). The results suggest that these active constituents from O. stamineus might be considered as new natural compounds for the development of anticancer agents via PTP1B inhibition.

Three new serratene-type triterpenoids (1–3) and a new hydroxy unsaturated fatty acid (13) together with nine known compounds (4–12) were isolated from Lycopodiella cernua. The chemical structures were established using NMR, MS, and Mosher’s method. Compound 13 showed the most potent inhibitory activity against acetylcholinesterase (AChE) with an IC50 value of 0.22 μM. For butyrylcholinesterase (BChE) inhibitory activity, 5 showed the most potent activity with an IC50 value of 0.42 μM. Compound 2 showed the most potent activity with an IC50 of 0.23 μM for BACE-1 inhibitory activity. The kinetic activities were investigated to determine the type of enzyme inhibition involved. The types of AChE inhibition shown by compounds 4, 5, and 13 were mixed; BChE inhibition by 5 was competitive, while 2 and 6 showed mixed-types. In addition, molecular docking studies were performed to investigate the interaction of these compounds with the pocket sites of AChE. The docking results revealed that the tested inhibitors 3, 4, and 13 were stably present in several pocket domains of the AChE residue.

Two new lanostane triterpenes, 3α,12β,15α-triacetoxy-5α-lanosta-7,9(11),24-trien-26-oic acid (1) and 5α-lanosta-8,24-diene-26,27-dihydroxy-3,7-dione (2), together with sixteen known compounds (3–18) were isolated from the fruiting bodies of the Vietnamese mushroom Ganoderma lucidum. Their chemical structures were determined by extensive spectroscopic (IR, HR-EI-MS, 1D and 2D NMR) analyses. Potential cytotoxic activities of these compounds were evaluated against human non-small cell lung adenocarcinoma (A549), breast adenocarcinoma (MCF-7), and prostatic small cell carcinoma (PC-3). Among the compounds, 3α,12β,15α-triacetoxy-5α-lanosta-7,9(11),24-trien-26-oic acid (1) showed significant cytotoxic activity against PC-3 cells with an IC50 of 11.5 μM. In studies of anti-angiogenesis activity, ganoderic acid F (17) was found to have the most potent inhibitory effect on the formation of capillary-like structures of human umbilical vein endothelial cells.

A novel pyrrolizidine alkaloids, madhumidine A (1), and two known alkaloids, lindelofidine benzoic acid ester (2) and minalobine B (3) were isolated from the leaves of Madhuca pasquieri (Dubard) H. J. LAM. The chemical structures of these alkaloids were established mainly by NMR techniques and mass spectrometry. Their anti-inflammatory activity was evaluated against lipopolysaccharide-induced nitric oxide production in macrophage RAW264.7 cell. In addition, the cytotoxic activity of all isolated compounds was tested against a panel of cancer cell lines.

Cytotoxic activity-guided fractionation of Erythrophleum fordii led to the isolation of two new cassaine diterpenoid-diterpenoid amide dimers, erythrophlesins H-I (1, 2). Spectral data indicated that they consist of asymmetrical dimeric structure via an ester bond between two cassaine diterpenoids. MTT assay confirmed that compound 1, erythrophlesin H, had the strongest cytotoxic effect toward the human prostate cancer cell line, PC-3. The molecular mechanism by which this compound induced apoptosis cell in prostate cancer remains unknown. Erythrophlesin H induced apoptosis in a dose-dependent manner. Acridine orange and annexin V-FITC/PI double staining confirmed that erythrophlesin H effectively induces apoptosis in PC-3 cells.

A new megastigmane glycoside, galloyl linarionoside A (1), together with 13 known compounds (2-14) were isolated from the aerial parts of Aceriphyllum rossii ENGLER. (Saxifragaceae). The chemical structures of the isolated compounds were established mainly by using nuclear magnetic resonance spectra, mass spectrometry, and modified Mosher's method. Among the isolates, compounds 4, 5, 6 and 7 showed potent inhibitory activity against the lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophage cells with IC50 values of 12.5, 9.5, 10.5 and 9.3 µM, respectively. The anti-inflammatory effect of compound 7 was accompanied by dose-dependent decreases in the production of inducible nitric oxide synthase and cyclooxygenase-2 proteins not in the inhibitor kappa B (IκB)-dependent nuclear factor-kappa B activation.

The present research was aimed to study the chemical compositions of Passiflora edulis Sims seeds oil, including the fatty acid profiles, contents of tocopherols, sterols, and triglycerides. The seeds oil yield is 24.88% by using Soxhlet method. Passiflora edulis seeds oil showed high levels of unsaturated fatty acids (89.25%) with main ingredient linoleic acid (w-6, 66.94%) and oleic acid (w-6, 18.86%). Tocopherols (18.04 mg/kg), sterols (2935.35 mg/kg) and triglycerides (monomere TAG, 74.11%) are also determined by using IOC and ISO methods, respectively. The findings demonstrate that P. edulis seeds oil could be used beneficially in the food and cosmetic industries.

Paramignya trimera (Oliv.) Guill. (Rutaceae), mostly distributed in the southern regions of Vietnam, has been used as a medicinal plant for treatment of liver diseases and cancer. From the methanol extract of the roots and stems of P. trimera, 3 new compounds (1-3) were isolated, including ninhvanin B (1), paramitrimerol (2), and parabacunoic acid (3), and a known alkaloid, citrusinine-I (4). The structures of these compounds were elucidated by electrospray ionization mass spectrometry and nuclear magnetic resonance spectral analysis, as well as by comparison with literature data.

Study on chemical constituents from the leaves and stems of Dysoxylum tpongense Pierre resulted in the isolation of six known compounds (1–6). The chemical structures of isolated compounds were identified as cabraleahydroxylactone (1), cabraleahydroxylactone-3-acetate (2), (+) spathulenol (3), b-sitosterol (4), stigmasterol (5), and stigmast-4-en-3-one (6) by comparison of the physicochemical, interpretation of NMR and mass spectral data with that reported in the literature.

Soluble epoxide hydrolases (sEH) are enzymes present in all living organisms, metabolize epoxy fatty acids to 1,2-diols. sEH in the metabolism of polyunsaturated fatty acids plays a key role in inflammation. In addition, the endogenous lipid mediators in cardiovascular disease are also broken down to diols by the action of sEH that enhanced cardiovascular protection. In this study, sEH inhibitory guided fractionation led to the isolation of five phenolic compounds trans-resveratrol (1), trans-piceatannol (2), sulfuretin (3), (+)-balanophonin (4), and cassigarol E (5) from the ethanol extract of the seeds of Passiflora edulis Sims cultivated in Vietnam. The chemical structures of isolated compounds were determined by the interpretation of NMR spectral data, mass spectra, and comparison with data from the literature. The soluble epoxide hydrolase (sEH) inhibitory activity of isolated compounds was evaluated. Among them, trans-piceatannol (2) showed the most potent inhibitory activity on sEH with an IC50 value of 3.4 μM. This study marks the first time that sulfuretin (3) was isolated from Passiflora edulis as well as (+)-balanophonin (4), and cassigarol E (5) were isolated from Passiflora genus.

Inhibition of cholinesterase has been proposed to be a therapeutic target for the treatment of Alzheimer's diseases. In our preliminary screening study on the acetylcholinesterase (AChE) inhibitory activity, an ethyl acetate soluble fraction of the roots of Harpagophytum procumbens (Pedaliaceae) was found to inhibit AChE activity at the concentration of 100 μg/mL. Ten compounds (1-10) were isolated from the active fraction and evaluated for their inhibitory effect on AChE and butyrylcholinesterase (BChE). Among the isolates, verbascosides (5, 6, and 8) containing a caffeoyl and a 3,4-dihydroxyphenethyl groups in their structures, showed effective AChE inhibitory activity and also possessed BChE inhibitory activity. The findings suggest that verbascoside derivatives may be partially related to the anti-Alzheimer effect of this medicinal plant.

Two new phenolic compounds, caesalpiniaphenols G-H (1 and 2), were isolated from Vietnamese Caesalpinia sappan heartwood. The chemical structures were established mainly by extensive spectroscopic studies and chemical evidence. Compounds 1 and 2 showed potent inhibitory activity against HL-60 cancer cell lines with respective IC50 values of 16.7 and 22.5 µg/mL. Treating HL-60 cells with various concentrations of 1 resulted in growth inhibition and the induction of apoptosis.

Two new phenolics, (3S,4R)-3,7,2',3'-tetrahydroxy-3,4-dihydro-9H-indeno[6,5-c]chromene (caesalpiniaphenol E, 1), and (3R,4S)-3,7-dihydroxy-3-(3'-methoxy-4'-hydroxyphenyl)-4-methoxychroman (caesalpiniaphenol F, 2), together with eleven known compounds (3-13), were isolated from the heartwood of Caesalpinia sappan. Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. Their anti-inflammatory activity was evaluated against LPS-induced NO production in macrophage RAW264.7 cells. Among them, compounds 10 and 13 showed strong inhibitory activities toward the LPS-induced NO production in macrophage RAW264.7 cells, with IC(50) values of 12.5 and 8.1 μm, respectively. In addition, compounds 10 and 13 inhibited the inductions of iNOS mRNA in dose-dependent manners, indicating that these compounds attenuated the synthesis of these transcripts at the transcriptional level.

Three new phenolics: ((7S)-8′-(benzo[3′,4′]dioxol-1′-yl)-7-hydroxypropyl)benzene-2,4-diol (1), ((7S)-8′-(4′-hydroxy-3′-methoxyphenyl)-7-hydroxypropyl)benzene-2,4-diol (2) and ((8R,8′S)-7-(4-hydroxy-3-methoxyphenyl)-8′-methylbutan-8-yl)-3′-methoxybenzene-4′,5′-diol (3), along with four known compounds (4–7) were isolated from the seeds of Myristica fragrans. Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. Their anti-inflammatory activity was evaluated against LPS-induced NO production in macrophage RAW264.7 cells.

Ganoderma lucidum is known as a medicinal mushroom used in traditional medicine. In our study, the cytotoxic activities of 17 compounds (1-17) isolated from the fruiting bodies of G. lucidum were investigated. Among them, ergosta-7,22-diene-2β,3α,9α-triol (EGDT) induced apoptosis in HL-60 human premyelocytic leukemia cells. EGDT activated the apoptotic process, including DNA fragmentation and caspase-3 activity. In immunoblotting analysis, treatment with EGDT resulted in the cleavage of procaspase-3 and poly(ADP-ribose) polymerase (PARP) into active forms. In the in vivo study, the administration (i.p.) of EGDT to Lewis lung carcinoma (LLC)-inoculated mice evidenced a significant inhibition of tumor growth. These results indicate that EGDT was one of the apoptotic constituents of G. lucidum, and might be an antitumor agent.

From the methanol extract of the heartwood of Dalbergia tonkinensis Prain collected in Buon Ma Thuot city, DakLak province, five flavonoids, liquiritigenin (1), 7,3',5'-trihydroxyflavanone (2), sativanone (3), 3'-O-methylviolanone (4) and sulfuretin (5) were isolated. The chemical structures of isolated compounds were determined by the interpretation of NMR spectral data as well as comparison with data from the literature. This study marks that 7,3',5'-trihydroxyflavanone (2) was isolated from the genus Dalbergia for the first time.

Two new dammarane-type glycosides, 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-[beta-d-glucopyranosyl(1-->4)-beta-d-glucopyranosyl]-20-O-[beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranoside] (1) and 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-beta-d-glucopyranosyl-20-O-[beta-d-6-O-acetylglucopyranosyl-(1-->2)-beta-d-glucopyranoside] (2), were isolated from a MeOH extract of the leaves of Gynostemma pentaphyllum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The isolated compounds showed potential inhibitory effects on eotaxin expression in BEAS-2B bronchial epithelial cells.

Two new flavonoid glycosides, (1, 2), and eleven known compounds, (3-13), were isolated from from a 70% EtOH extract of the leaves of Chromolaena odorata (Asteraceae). Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The newly isolated compounds were tested in vitro for their cytotoxic activities against the LLC and HL-60 cancer cell lines. Compound 1 showed cytotoxicity against LLC and HL-60 cancer cell lines with IC(50) values of 28.2 and 11.6 µM, respectively. Compound 2 exhibited significant cytotoxic activity in the inhibition of HL-60 cancer cell lines with IC(50) value of 10.8 µM.

Two new compounds, erythroformide (I) and 3β-acetoxynorcassamide (II), are isolated together with four known compounds and their effects on endothelial tube formation on matrigel are investigated.

A new alkenylphenol, bavinol A (1), together with six known compounds (2–7) were isolated from the aerial parts of Piper bavinum (Piperaceae). The chemical structures of these compounds were determined by spectroscopic analyses including 2D NMR spectroscopy. The anti-Alzheimer effects of compounds 1–7 were evaluated from acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity assays. Bavinol A (1), ampelopsin (3), and violanthin (4) exhibited AChE inhibitory activities with IC50 values of 29.80, 59.47 and 79.80 μM. Compound 1 also showed the most potent BChE inhibitory activity with an IC50 value of 19.25 μM.

Cleistocalyx operculatus (Roxb.) Merr and Perry (Myrtaceae) is a well-known medicinal plant, widely distributed and propagated in China, Vietnam and some other tropical countries. Several species of Cleistocalyx are used in folk medicine. In Vietnam, C. operculatus is commonly called “Voi”. The flower buds (“Nu Voi”) and leaves (“La Voi”) have been used to make a beverage since ancient times. 1 The buds are commonly used as an ingredient for tonic drinks in Southern China. 2 The water extract of C. operculatus buds was shown to increase the contractility and decrease the frequency of contraction in an isolated rat heart perfusion system. 3 It showed strong protective effects on lipid peroxidation in rat liver microsomes and on the H2O2induced trauma of PC12 cells. 4 C. operculatus extract showed inhibitory activity against the α-glucosidase, rat-intestinal maltase, sucrase activities, and is considered a promising material for preventing and treating diabetes. 5 Recently, the essential oil of the C. operculatus buds was investigated for its in vitro and in vivo anti-inflammatory activities. These results suggested that its essential oil might exert an anti-inflammatory effect by suppressing the expression of pro-inflammatory cytokines, which is mediated, at least in part, by blocking the NF-κB activation. 6

isolation, structural elucidation and antiinflammatory activity of two new phenolics, caesalpiniaphenol E (I) and caesalpiniaphenol F (II), along with eleven known compounds

Arginase II has recently reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. In the course of screening plants used in natural medicines as arginase II inhibitory activity, a methanol extract of Scutellaria indica showed significant inhibitory effect. Further fractionation and repeated column chromatography led to the isolation of a new flavan-type (1), and seven known compounds (2–8). The chemical structures of isolated compounds were elucidated based on extensive 1D and 2D NMR spectroscopic data. The isolates 1–8 were investigated in vitro for their arginase II inhibitory activity using enzyme solution prepared from kidney of anesthetized C57BL/6 mice. Compounds 3 and 5 significantly inhibited arginase II activity with IC50 values of 25.1 and 11.6 μM, respectively, whereas the other compounds were apparently inactive.

Four new phenolic compounds, caesalpiniaphenols A-D (1-4), together with eight known compounds were isolated from Caesalpinia sappan heartwood. The chemical structures were established mainly by NMR, MS, ECD, and Mosher's method. Compounds 4, 5, and 7 showed weak inhibitory activity against the LPS-induced NO production in macrophage RAW264.7 cells with IC(50) values of 12.2, 3.5, and 5.7 μM, respectively.

Elevated plasma cholesterol is a hallmark of numerous cardiovascular diseases that are closely linked to endothelial dysfunction indicating decreased nitric oxide (NO) production in the endothelium. It has been previously demonstrated that piceatannol-3'-O-β-D-glucopyranoside (PG) inhibits arginase activity and reciprocally regulates NO production. Here, we aimed to ascertain whether PG ameliorates vascular function in wild-type (WT) and atherogenic model mice [apolipoprotein E-null mice (ApoE-/-)] and to investigate the possible underlying mechanism. Preincubation of aortic vessels from WT mice fed a normal diet (ND) with PG attenuated vasoconstriction response to U46619 and phenylephrine (PE), while the vasorelaxant response to acetylcholine (Ach) was markedly enhanced in an endothelium-dependent manner. However, the endothelium-independent NO donor, sodium nitroprusside (SNP), did not change vessel reactivity. In thoracic aorta from ApoE-/- mice, a high-cholesterol diet (HCD) induced an increase in arginase activity, a decrease in NO release and an increase in reactive oxygen species generation that was reversed by treatment with PG. The effect of PG was associated with enhanced stability of the eNOS dimer and was not dependent on the expression levels of arginase II and eNOS proteins, although eNOS expression was increased in ApoE-/- mice fed an HCD. Furthermore, PG treatment attenuated the PE-dependent contractile response, and significantly improved the Ach-dependent vasorelaxation response in aortic rings from ApoE-/- mice fed an HCD. On the other hand, PG incubation neither altered the contractile response to a high K+ solution nor the relaxation response to SNP. When analyzing the L-arginine content using high-performance liquid chromatography, PG incubation increased the intracellular L-arginine concentration. PG administration in the drinking water significantly reduced fatty streak formation in ApoE-/- mice fed an HCD. These data indicate that PG improves the pathophysiology of cholesterol-mediated endothelial dysfunction. Therefore, we conclude that the development of PG as a novel effective therapy for preventing atherosclerotic diseases is warranted.

Two new flavonoid glycosides, (1, 2), and eleven known compounds, (3-13), were isolated from from a 70% EtOH extract of the leaves of Chromolaena odorata (Asteraceae). Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The newly isolated compounds were tested in vitro for their cytotoxic activities against the LLC and HL-60 cancer cell lines. Compound 1 showed cytotoxicity against LLC and HL-60 cancer cell lines with IC(50) values of 28.2 and 11.6 µM, respectively. Compound 2 exhibited significant cytotoxic activity in the inhibition of HL-60 cancer cell lines with IC(50) value of 10.8 µM.

A new alkaloid, methyl 2'-(7,8-dihydrosanguinarine-8-yl)acetate (1), together with six known alkaloids, stylopine (2), protopine (3), norchelidonine (4), chelidonine (5), berberine (6), and 8-hydroxydihydrosanguinarine (7), were isolated from Chelidonium majus. Their chemical structures were primarily established using 1D and 2D NMR techniques and mass spectrometry. The anti-inflammatory activity of the isolates was examined for their inhibitory effects on LPS-induced NO production in macrophage RAW264.7 cells. Among them, compounds 5 and 7 showed strong inhibitory activities toward the LPS-induced NO production in macrophage RAW264.7 cells with IC(50) values of 7.3 and 4.5 μM, respectively. In addition, compounds 5 and 7 inhibited the inductions of COX-2 and iNOS mRNA in dose-dependent manners, indicating that these compounds attenuated the syntheses of these transcripts at the transcriptional level.

Compound (I) is isolated from the water-soluble fraction of the buds of the title medicinal plant together with 6 known compounds.

Four new 28-nor-oleanane-type triterpene oligoglycosides, camellenodiol 3-O-β-D-galactopyranosyl(1→2)[β-D-xylopyranosyl(1→2)-β-D-galactopyranosyl(1→3)]-β-D-glucuronopyranoside (2), camellenodiol 3-O-4''-O-acetyl-β-D-galactopyranosyl(1→2)[β-D-xylopyranosyl(1→2)-β-D-galactopyranosyl(1→3)]-β-D-glucuronopyranoside (4), camellenodiol 3-O-(β-D-galactopyranosyl(1→2)[β-D-xylopyranosyl(1→2)-β-D-galactopyranosyl(1→3)]-6'-methoxy-β-D- glucuronopyranoside (5), and maragenin II 3-O-(β-D-galactopyranosyl(1→2)[β-D-xylopyranosyl(1→2)-β-D-galactopyranosyl(1→3)]-6'-methoxy-β-D-glucuronopyranoside (6), along with two known compounds, (1 and 3), were isolated from the stem bark of Camellia japonica. Their chemical structures were established mainly by 2D NMR techniques and mass spectrometry. The isolated compounds showed inhibitory effects on NO production in RAW264.7 macrophages.

In order to facilitate the quality control of some selected Korean thistles (Cirsii Herb), Cirsium japonicum var ussuriense, C. japonium var spinosissimum, C. setidens, C. pendulum, C. nipponicum, Carduus crispus, and Breea segetum, a simple, accurate and reliable high performance liguid chromatography method was developed for the simultaneous determination of the six flavonoids: luteolin 5-O-glucoside (1), luteolin 7-O-glucoside (2), hispidulin 7-O-neohesperidoside (3), luteolin (4), pectolinarin (5), and apigenin (6), which were selected as the chemical markers of the thistles. Separation was achieved on an Agilent Eclipse XDB-C18 column with a gradient solvent system of 0.1% trifluoroacetic acid aqueous-methanol at a flow-rate of 1.0 mL/min and detected at 254 nm. All six calibration curves showed good linearity (R 2 > 0.991). The method was reproducible with intra- and inter-day variations of less than 6%. The recoveries were in the range of 90.01–100.05%. This analysis method was successfully utilized to quantify the six flavonoids in the 22 batches of the thistles. The results demonstrated that this method is simple, reliable and suitable for the quality control of this medicinal herb.

Five flavonoids, myricetin-3'-methylether 3-O-β-D: -galactopyranoside (1), myricetin-3',5'-dimethylether 3-O-β-D: -galactopyranoside (2), quercetin (3), kaempferol (4), and tamarixetin (5) were isolated from the buds of Cleistocalyx operculatus (Myrtaceae). The chemical structures of these compounds were determined on the basis of spectroscopic analyses, including 2D NMR. Their anti-Alzheimer effects were evaluated via acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity assays. All five compounds 1-5 showed potential inhibitory activities against AChE with IC(50) values of 19.9, 37.8, 25.9, 30.4 and 22.3 μM, respectively, while compounds 1, 3, 4 and 5 also possessed BChE inhibitory activity with IC(50) values of 152.5, 177.8, 62.5, and 160.6 μM, respectively.

In this study, we evaluated the anti-inflammatory activity of the soluble ethyl acetate fraction and chemical components of the stem bark of Passiflora foetida (Passifloraceae). Ten flavonoids (1–10) were isolated by various chromatographic techniques, and their structures were determined based on spectroscopic analyses by using nuclear magnetic resonance (NMR). Luteolin (2) and chrysoeriol (3) showed the most potent inhibition of nitric oxide (NO) production in macrophage cell line, RAW264.7, with half maximal inhibitor concentration (IC50) values of 1.2 and 3.1 μM, respectively. These compounds suppressed lipopolysaccharide (LPS)-induced inducible NO synthase (iNOS) expression at the transcription level. Our research indicates that the stem bark of P. foetida has significant anti-inflammatory properties, suggesting that its flavonoids may have anti-inflammatory benefits.

Many natural products have been shown to have an inhibitory effect on nitric oxide (NO), and are used as chemotherapy agents for inflammation disease. The current study was designed to evaluate the anti-inflammatory activity of chemical components from the leaves of Ampelopsis cantoniensis. Sixteen compounds (1–16) were isolated and identified. Phloretin (5) and 5,7,3′,5′-tetrahydroxyflavanone (16) inhibited nitric oxide (NO) production with IC50 values of 5.2, and 18.5 μM, respectively. The inhibitory effect of compounds 5 and 16 were accompanied by dose-dependent decreases in LPS-induced nitric oxide synthase (iNOS) in RAW 264.7 cells, respectively. This study investigated the significant anti-inflammatory properties of isolated compounds from the leaves of A. cantoniensis for the first time. The findings demonstrate that A. cantoniensis could be used beneficially in the treatment of inflammation disease.

Caesalpinia sappan (C. sappan) is a medicinal plant used for promoting blood circulation and removing stasis. During a screening procedure on medicinal plants, the ethylacetate extract of the lignum of C. sappan (CLE) showed inhibitory activity on arginase which has recently been reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. CLE inhibited arginase II activity prepared from kidney lysate in a dose-dependent manner. In HUVECs, inhibition of arginase activity by CLE reciprocally increased NOx production through enhancement of eNOS dimer stability without any significant changes in the protein levels of eNOS and arginase II expression. Furthermore, CLE-dependent arginase inhibition resulted in increase of NO generation and decrease of superoxide production on endothelium of isolated mice aorta. These results indicate that CLE augments NO production on endothelium through inhibition of arginase activity, and may imply their usefulness for the treatment of cardiovascular diseases associated with endothelial dysfunction.