Inhibitory Effects of Compounds from Plumula nelumbinis on Biofilm and Quorum Sensing Against P. aeruginosa.

Quorum sensing (QS), which controls the survival and virulence of Pseudomonas aeruginosa, including the formation of biofilm, is considered to be a new target to overcome pathogens. The aim of this study was to identify new QS inhibitors against P. aeruginosa and provide potential treatments for clinical infections. In this study, 25 compounds were isolated from Plumula nelumbini. Among these compounds, C25 showed the most significant biofilm inhibition activity, reaching 44.63% at 100 µM without inhibiting bacterial growth. Furthermore, C25 showed significant inhibition activity of rhamnolipid, pyocyanin, and elastase. Further mechanistic studies have confirmed that C25 could downregulate key genes in the QS system, including lasI, lasR, lasA, lasB, and pqsR, and Molecular docking studies have shown that C25 can bind to the active sites of the LasR and PqsR receptors. The present study suggests that C25 is a promising QS inhibitor for treating P. aeruginosa infections.

Nine prenylated acylphloroglucinols with potential anti-depressive and hepatoprotective activities from Hypericum scabrum.

In our screening program for new biologically active secondary metabolites, nine new polycyclic polyprenyled acylphloroglucinols, hyperscabins D-L, together with three known compounds, were obtained from the aerial parts of Hypericum scabrum. The chemical structures of 1-9 were characterized by extensive spectroscopic analyses, nuclear magnetic resonance calculation with DP4+ probability analysis, and the electronic circular dichroism spectra were calculated. Compound 1 was an unusual prenylated acylphloroglucinol decorated with a 5-oxaspiro [4,5] deca-1,9-dione skeleton. Compound 2 was a newly identified spirocyclic polyprenylated acylphloroglucinol possessing a rare 5,5-spiroketal segment. Compounds 3, 8, and 10 (10 µM) exhibited pronounced hepatoprotective activity against d-galactosamine-induced WB-F344 cell damage in vitro assays. All test compounds (1, 3, and 7-12) demonstrated potential inhibitory effects at 10 µM against noradrenalinet ([3H]-NE) reuptake in rat brain synaptosome.

Structures and biological evaluation of phenylpropanoid derivatives from Murraya koenigii.

Four new phenylpropanoid derivatives (1-4), together with eleven known analogues (5-15) were isolated and identified by comparison with their references and extensive spectroscopic methods from Murraya koenigii for the first time. Compounds (1-15) were assayed for their inhibitory activities by measuring IL-6-induced STAT3 promoter activities in HepG2 cells, and found compounds 1, 2, 6, and 15 showed inhibitory effects with IC50 values of 11.5, 18.7, 8.9, and 22.7 µM, respectively. The inhibitory activities of compounds (1-15) were screened against NO production in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells, and found compounds 3, 4, 9, 11, and 14 exhibited inhibitions against LPS-induced NO production in RAW264.7 macrophages, with IC50 values of 32.7, 7.9, 42.1, 58.9, and 62.4 µM, respectively.

Alkenes with antioxidative activities from Murraya koenigii (L.) Spreng.

Four new alkenes (1-4), and six known alkenes (5-12) were isolated from Murraya koenigii (L.) Spreng. Their structures were elucidated on the basis of spectroscopic analyses and references. Compounds (1-12) were evaluated for antioxidative activities. Among them, compounds 1, 2, 4, and 7 exhibited significant antioxidative activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with IC50=21.4-49.5 µM. The known compounds (5-12) were isolated from this plant for the first time.

Two new prenylated phloroglucinol derivatives from Hypericum scabrum.

Two new prenylated phloroglucinol derivatives (1-2), and a known compound furohyperforim isomer 2 (3), were isolated from the aerial parts of Hypericum scabrum. Their structures were elucidated by various spectroscopic methods, including MS, IR, UV, and NMR.

Polygonumnolides C1-C4; minor dianthrone glycosides from the roots of Polygonum multiflorum Thunb.

Four new dianthrone glycosides, named polygonumnolides C1-C4 (1-4), were isolated from the dried roots of Polygonum multiflorum Thunb, together with two known emodin dianthrones (5-6). Their hepatotoxicities were evaluated against L-02 cell lines. Compounds 1-4 showed weak hepatotoxicity against L-02 cell lines with IC50 values of 313.05, 205.20, 294.20, and 207.35 µM, respectively.

Cembranoids from the Gum Resin of Boswellia carterii as Potential Antiulcerative Colitis Agents.

Eight new cembranoids, boscartins A-H (1, 2, and 4-9), and the known incensole oxide were isolated from the gum resin of Boswellia carterii. The absolute configurations of 1, 2, 4, and incensole oxide were unequivocally resolved using single-crystal X-ray diffraction analysis with Cu Kα radiation, and the absolute configuration of 5 was resolved via electronic circular dichroism data. The antiulcerative colitis activities of the compounds were evaluated in an in vitro x-box-binding protein 1 (XBP 1) transcriptional activity assay using dual luciferase reporter detection. At 10 µM, compounds 1, 5, 6, and 7 significantly activated XBP 1 transcription with EC50 values of 0.34, 1.14, 0.88, and 0.42 µM, respectively, compared with the pGL3-basic vector control.

Effect of Hypericum perforatum L. extract on insulin resistance and lipid metabolic disorder in high-fat-diet induced obese mice.

Natural product Hypericum perforatum L. has been used in folk medicine to improve mental performance. However, the effect of H. perforatum L. on metabolism is still unknown. In order to test whether H. perforatum L. extract (EHP) has an effect on metabolic syndrome, we treated diet induced obese (DIO) C57BL/6J mice with the extract. The chemical characters of EHP were investigated with thin-layer chromatography, ultraviolet, high-performance liquid chromatography (HPLC), and HPLC-mass spectrometry fingerprint analysis. Oral glucose tolerance test (OGTT), insulin tolerance test (ITT), and the glucose infusion rate (GIR) in hyperinsulinemic-euglycemic clamp test were performed to evaluate the glucose metabolism and insulin sensitivity. Skeletal muscle was examined for lipid metabolism. The results suggest that EHP can significantly improve the glucose and lipid metabolism in DIO mice. In vitro, EHP inhibited the catalytic activity of recombinant human protein tyrosine phosphatase 1B (PTP1B) and reduced the protein and mRNA levels of PTP1B in the skeletal muscle. Moreover, expressions of genes related to fatty acid uptake and oxidation were changed by EHP in the skeletal muscle. These results suggest that EHP may improve insulin resistance and lipid metabolism in DIO mice.

Hepatoprotective benzofurans and furanolignans from Gymnema tingens.

Two new benzofurans, gymnefuranols A (1) and B (2), together with six known furanolignans (3-8), were isolated from Gymnema tingens. The structures of the new compounds were elucidated by comprehensive analysis of the NMR and HR-MS data. Compounds 1, 2, 6, and 7 showed hepatoprotective activities against D-galactosamine-induced HL-7702 cell damage.

Two new oligostilbenes from the stem of Parthenocissus quinquefolia.

Two new oligostilbenes, parthenocissins M (1) and N (2), together with two known compounds, miyabenol C (3) and ϵ-viniferin (4), were isolated from the stem of Parthenocissus quinquefolia. Their structures were elucidated by means of NMR, UV, IR, and MS data.

New dimeric phthalides from Ligusticum sinense Oliv cv. Chaxiong.

A new dimeric phthalide, chaxiongnolide A (1), and a new natural product, chaxiongnolide B (2), together with a known compound Z-ligustilide (3), were isolated from the rhizome of Ligusticum sinense Oliv cv. Chaxiong. Their structures were elucidated by various spectroscopic methods and confirmed by X-ray crystallographic analysis.

Two new polyprenylated acylphloroglucinols from Hypericum scabrum.

Two new polyprenylated acylphloroglucinols, (1S,32R,5S,6R,7R)-6-((R)-3,4-di-hydroxy-4-methylpentyl)-2-(2-hydroxypropan-2-yl)-7-isobutyryl-6-methyl-5,9-bis(3-methylbut-2-en-1-yl)-4,5,6,7-tetrahydro-2H-32,7-methanocycloocta[b]furan-8,10(3H)-dione (1) and (4R,5R,7R)-4-((R)-3,4-dihydroxy-4-methylpentyl)-2,2,4-trimethyl-5,7-bis(3-methyl-but-2-en-1-yl)-7-(5-methylhex-4-enoyl)-4,5,6,7-tetrahydrobenzofuran-3(2H)-one (2) were isolated from Hypericum scabrum. The structures were elucidated by means of spectroscopic methods, including MS, IR, NMR, OR, and CD.

Two new cucurbitane triterpenoids from the seeds of Momordica charantia.

Two new cucurbitane triterpenoids 1 and 2 were isolated, together with six known compounds, from the seeds of Momordica charantia L. The structures of new compounds were determined to be 3-O-{[ß-d-galactopyranosyl(1 â†’ 6)]-O-ß-d-galactopyranosyl}-23(R), 24(R), 25-trihydroxycucur-bit-5-ene (1), 3-O-[ß-d-galactopyranosyl]-25-O-ß-d-galactopyranosyl-7(R), 22(S), 23(R), 24(R), 25-pentahydroxycucurbit-5-ene (2), respectively. Their structures were elucidated by the combination of mass spectrometry, one- and two-dimensional NMR experiments and chemical reactions.

Composition and antioxidant activity of the anthocyanins of the fruit of Berberis heteropoda Schrenk.

In present study, the anthocyanin composition and content of the fruit of B. heteropoda Schrenk were determined for the first time. The total anthocyanins were extracted from the fruit of B. heteropoda Schrenk using 0.5% HCl in 80% methanol and were then purified using an AB-8 macroporous resin column. The purified anthocyanin extract (PAE) was evaluated by high-performance liquid chromatography with a diode array detector (HPLC-DAD) and HPLC-high resolution-electrospray ionization-mass spectrometry (HPLC-HR-ESI-MS) under the same experimental conditions. The results revealed the presence of seven different anthocyanins. The major anthocyanins purified by preparative HPLC were confirmed to be delphinidin-3-O-glucopyranoside (30.3%), cyanidin-3-O-glucopyranoside (33.5%), petunidin-3-Ο-glucopyranoside (10.5%), peonidin-3-O-glucopyranoside (8.5%) and malvidin-3-O-glucopyranoside (13.8%) using HPLC-HR-ESI-MS and NMR spectroscopy. The total anthocyanin content was 2036.6 ± 2.2 mg/100 g of the fresh weight of B. heteropoda Schrenk fruit. In terms of its total reducing capacity assay, DPPH radical-scavenging activity assay, ferric-reducing antioxidant power (FRAP) assay and ABTS radical cation-scavenging activity assay, the PAE also showed potent antioxidant activity. The results are valuable for illuminating anthocyanins composition of B. heteropoda Schrenk and for further utilising them as a promising anthocyanin pigment source. This research enriched the chemical information of B. heteropoda Schrenk.

Two new bidesmoside triterpenoid saponins from the seeds of Momordica charantia L.

Two new bidesmoside triterpenoid saponins which were identifed as 28-O-ß-D-xylopyranosyl(1→3)-ß-D-xylopyranosyl(1→4)-α-L-rhamnopyranosyl(1→2)-[α-L-rhamno-pyranosyl(1→3)]-ß-D-fucopyranosyl gypsogenin 3-O-ß-D-glucopyranosyl (1→2)-ß-D-glucopyranosiduronic acid (C1) and 28-O-ß-D-xylopyranosyl(1→4)-α-L-rhamnopyranosyl (1→2)-[α-L-rhamnopyranosyl(1→3)]-ß-D-fucopyranosyl gypsogenin 3-O-ß-D-gluco-pyranosyl(1→2)-ß-D-glucopyranosiduronic acid (C2) were isolated together with two known compounds from the seeds of Momordica charantia L. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments and chemical reactions.

[A new lanostane-type triterpenoid from Cymbopogon citratus].

To study the chemical constituents of Cymbopogon citratus, isolation and purification of constituents were carried out on silica gel, Sephadex LH-20 and prepatative HPLC. The structures of the compounds were identified by physicchemical properties and spectral data analysis. Eight compounds were isolated and identified as 3beta-methoxy lanosta-9(11)-en-27-ol (1), 3beta-hydroxylanosta-9 (11)-en (2), (24S) -3beta-methoxylanosta-9(11), 25-dien-24-ol (3), 8-hydroxyl-neo-menthol (4), (2E)-3,7-dimethyl-2,7-octadiene-1, 6-diol (5), (+)-citronellol (6), 7-hydroxymenthol (7) and ethyl nonadecanoate(8). Compounds 1 is a new one. Compounds 2-3 are obtained from C. citratus for the first time.

Hepatoprotective prenylaromadendrane-type diterpenes from the gum resin of Boswellia carterii.

Chemical examination of the exuded gum resin of Boswellia carterii resulted in the isolation of nine new prenylaromadendrane-type diterpenes, boscartols A-I (1-9). The structures of these compounds were established by extensive 1D and 2D NMR spectroscopic analyses, mass spectrometric data, and circular dichroism spectra. Compounds 1-3, 5, 6, 8, and 9 (10 µM) showed moderate hepatoprotective activity against d-galactosamine-induced HL-7702 cell damage.

Hepatoprotective phenolic glycosides from Gymnema tingens.

Six new phenolic diglycosides, named gymnetinosides A-F (1-6), were isolated from the ethanolic extract of Gymnema tingens, together with three known diglycosides, sequinoside K (7), khaephuoside B (8), and albibrissinoside A (9). The structures of the new compounds were determined by spectroscopic techniques including 1D-, 2D NMR, mass spectroscopy, and circular dichroism. Compounds 1, 5, and 6 showed hepatoprotective activities against D-galactosamine-induced HL-7702 cell damage.

Three new phloroglucinol derivatives from Hypericum scabrum.

A chemical investigation on the aerial parts of Hypericum scabrum L. resulted in the isolation of three new phloroglucinol derivatives, hyperscabrins A (1), B (2), and C (3), together with one known compound, (2R,3R,4S,6R)-3-methyl-4,6-di(3-methyl-2-butenyl)-2-(2-methyl-1-oxopropyl)-3-(4-methyl-3-pentenyl)-cyclohexanone (4). The structures were elucidated by means of spectroscopic methods, including MS, IR, 1D NMR, and 2D NMR, and the absolute configurations of chiral centers in these phloroglucinol derivatives were determined for the first time by studying their circular dichroism spectra.

[Chemical constituents from Hypericum perforatum].

OBJECTIVE: To study the chemical constituents from Hypericum perforatum. METHOD: Compouds were isolated by chromatographic techniques. Their structures were identified by spectral methods. The inhibitory activity of recombinant human PTP1B was evaluated. RESULT: Nine compounds were elucidated as D-Mannitol (1), 1,2-benzenedicarboxylic acid bis(1-methylpropyl) ester (2), (7E, 6R,9S)-9-hydroxy-4,7-megastigmadien-3-one (3), (6S,9R)-roseoside (4) , 2,6-dimethoxy-4-hydroquinone-l-O-beta-D-glucopyranoside (5), 2,6-di-methoxy-4-hydroxybenzyl alcohol 1 -O-beta-D-glucopyranoside (6), syringate 4-O-beta-glucopyranoside (7), hypericin (8), skyrin-6-0-beta-D-glucopyranoside (9) , (R)-2,3-dihydroxypropyl 3,4-dihydroxy-benzoate (10). At a concentration of 2 micromol x L(-1), compound 8 inhibited recombinant human PTP1B with inhibitory rate of 96.4% and IC50 of 2.5 micromol x L(-1). CONCLUSION: compound 10 was new, compounds 2-4, 7 were obtained from Hypericum for the first time and compounds 5-6 was isolated from this plant for the first time. Compound 8 showed remarkable PTP1B inhibitory activity.