Phytochemical studies on the whole herb of Sphaerophysa salsula has resulted in the discovery of one new 8-isopentenyl isoflavone derivative, named sphaerosin s2 (3-(8-(2-hydroxypropan-2-yl)-3,4-dihydro-2H-furo[2,3-h]chromen-3-yl)-2,6-dimethoxyphenol) (1), along with four know 8-isopentenyl isoflavone derivatives (2-5). Compounds (2, 4 and 5) were isolated for the first time from this species. Their structures were elucidated on the basis of ESI-MS, UV, IR, 1D NMR and 2D NMR data.
OBJECTIVES: The hepatoprotective effect of Gentianae macrophyllae root extract (GME) on alcoholic liver disease (ALD) was evaluated through ethanol induced ALD animal model.METHODS: Mice were randomly divided into control normal group (10 mice), ethanol-induced ALD model group (10 mice) and GME plus ethanol group (30 mice). Mice in model group were given intragastric administration with 50% (v/v) ethanol aqueous solution (200 μl for each) once daily for 19 days. Mice in control normal group received equal volumes of water. Mice in GME plus ethanol group were given intragastric administration with 50% (v/v) ethanol aqueous solution (200 μl for each) once daily at 10:00 a.m., after 1 h, mice in GME group sequentially were treated with 20, 40 and 100 mg/kg of GME by gastric gavage for 19 days. the average food and water consumed by the mice in every group were recorded every 2 days and body weight of every mouse in every group was measured every 2 days.
KEY FINDINGS: Results showed that GME significantly improved alcohol induced liver injury in a dose-dependent manner. The impaired hepatic tissue structure was repaired and the collagen deposition declined after GME administration. Meanwhile, the level of malonaldehyde (MDA), Aspartate transaminase (AST) and alanine transaminase (ALT) (indicators of liver damage) in blood serum were significantly controlled by GME with a dose-dependent manner, moreover, body weight and liver index were also improved after administration of GME. Pro-inflammatory cytokines including MCP-1, TNF-α, IL-1 and IL-6 were detected through RT-PCR and ELISA in experiment and GME can significantly inhibit the expression of TNF-α, IL-1 and IL-6 but have no effect on MCP-1. In order to explore the mechanism of GME on ALD, MAPKs pathway was examined and results indicated that GME attenuated ALD through inhibiting the phosphorylation of JNK and P38 and further suppressing the initiation of inflammation.
CONCLUSIONS: GME attenuated ALD through inhibiting the phosphorylation of JNK and P38 and further suppressing the initiation of inflammation.
Background: Dracocephalum heterophyllum was a traditional Tibetan medicine possesses various pharmacological effects involved in anti-inflammatory, antibacterial activities. However, its anti-hepatitis, antioxidant activity and bioactive compounds have not been reported, the objective of this research work was to investigate the pharmacological activity and bioactive compounds of D. heterophyllum extracts. Results: In the present study, the anti-hepatics and antioxidant activities of four D. heterophyllum extracts (i.e. petroleum ether extracts, ethyl acetate extracts, n-BuOH extracts, and water extracts) were conducted. The main chemical constituent of petroleum ether and ethyl acetate extracts were also isolated using chromatographic techniques and identified by NMR spectroscopic methods. The anti-hepatitis assay showed that the petroleum ether and ethyl acetate extracts of D. heterophyllum significantly prolonged the mean survival times and reduced the mortality of mouse hepatitis model induced by concanavalin A (ConA). The levels of alanine transaminase, aspartate transaminase in blood serum could be decreased obviously by ethyl acetate extracts compared with ConA group (P < 0.01). The histological analysis demonstrated that the ethyl acetate extracts could inhibit apoptosis and necrosis caused by ConA. In addition, the antioxidant activities of the four extracts of D. heterophyllum were measured by DPPH assay, ABTS assay, anti-lipidperoxidation assay, ferric reducing antioxidant power assay, ferrous metal ions chelating assay and determination of total phenolic contents. The results showed that the ethyl acetate extract had the highest antioxidant activities, followed by petroleum ether extract. Finally, nine mainly compounds were isolated from the Petroleum ether and ethyl acetate extracts, including four triterpenes: oleanolic acid ( 1), ursolic acid ( 2), pomolic acid ( 3), 2α- hydroxyl ursolic acid ( 4), three flavonoids: apigenin-7- O-rutinoside ( 5), luteolin ( 8), diosmetin ( 9) and two phenolic acids: rosmarinic acid ( 6), methyl rosmarinate ( 7). Conclusion: The Ethyl acetate extract of D. heterophyllum had the highest anti-hepatitis and antioxidants activities, followed by petroleum ether extract. The bioactive substances may be triterpenes, flavonoids and phenolic acids, the ethyl acetate extracts of D. heterophyllum may be possible candidates in developing anti-hepatitis medicine.
BACKGROUND: In previous investigation, we have identified antioxidative effects of water-soluble ethanolic extracts (named as AKE) from Arenaria kansuensis and inferred that these extracts or their constituents may also have antihypoxic activity. A. kansuensis has been widely used in traditional Tibetan medicine for altitude sickness (AS) and has been known as the herb of anti-inflammatory and hypoxia resistance for a long time.PURPOSE: The purpose of this study is to evaluate protective effects of AKE and its major constituents against hypoxia-induced lethality in mice and RSC96 cells.
STUDY DESIGN AND METHODS: Hypoxia-induced lethality in mice was investigated by 3 experimental animal models of hypoxia. Meanwhile, we established a RSC96 cell model of hypoxia which applied to screen and assess the anti-hypoxic activity of compounds isolated from A. kansuensis.
RESULTS: Results indicated that AKE dose-dependently prolonged survival time of hypoxia induced lethality in mice compared to vehicle group and exhibited significantly anti-hypoxic effect. AKE also enhanced the number of red blood cells (RBC) and the concentration of hemoglobin (HB). 8 compounds were bio-guided separated and purified from AKE based on the animal model and cell model of hypoxia. Among which pyrocatechol (C16) and tricin 7-O-β-d-glucopyranoside (C13) were confirmed to express better protective effects on cell damage induced by hypoxia, suggesting that these two compounds are major active constituents of AKE for anti-hypoxia.
CONCLUSION: This study demonstrated that pyrocatechol and tricin 7-O-β-d-glucopyranoside could be therapeutic candidates for treatment of AS. It is the first time to find the major active constituents of AKE for anti-hypoxia. Meanwhile, a RSC96 cell model of hypoxia was established to screen anti-hypoxic activity of compounds for the first time.
Background: Hypecoum leptocarpum Hook. f. et Thoms., which is used in traditional Tibetan medicine as an antipyretic, antitussive, analgesic, and anti-inflammatory agent, contains a variety of alkaloids that could be responsible for its analgesic and anti-inflammatory properties. Objective: The present study was designed to investigate the anti-inflammatory activity of the total alkaloids from H. leptocarpum (AHL) in vitro and to elucidate the chemical structure of the anti-inflammatory components in AHL. Materials and Methods: Chemical characterization was performed using liquid chromatography/quadrupole-time-of-flight mass and diode-array detector-high performance liquid chromatography. The anti-inflammatory effects of AHL were investigated by measuring the production of inflammatory cytokines using enzyme-linked immunosorbent assay and mRNA expression by real-time polymerase chain reaction in lipopolysaccharide-induced RAW 264.7 macrophages. Results: Chemical analysis of AHL revealed the presence of seven alkaloids, protopine (13.3%), cryptopine (1.5%), leptopidinine, leptocarpine, corydamine, dihydroleptopine, and oxohydrastinine. AHL significantly suppressed the production of nitric oxide (NO), interleukin-1 beta (IL-1 β), IL-6, and tumor necrosis factor-alpha (TNF-α) in LPS-induced RAW 264.7 cells. The maximum levels of suppression of NO, IL-1 β, IL-6, and TNF-α were 86.8% ± 2.2%, 70.1% ± 1.5%, 100.1% ± 2.5%, and 50.8% ± 3.6%, respectively. IC50values of suppression of cytokine production by AHL were 7.47 ± 2.81 μg/mL (NO), 0.12 ± 0.28 μg/mL (IL-1 β), 0.56 ± 0.37 μg/mL (IL-6), and 18.95 ± 5.23 μg/mL (TNF-α). AHL was also shown to downregulate mRNA expression of inducible NO synthase, IL-1 β, IL-6, and TNF-α in vitro. Conclusion: The study provides convincing evidence that AHL has strong anti-inflammatory activity. The potent activity is likely a result of synergy between the different alkaloids. Abbreviations used: The total alkaloids from H. leptocarpum: AHL; Nitric oxide: NO; Interleukin-1 beta IL-1β; Interleukin-6: IL-6; Tumor necrosis factor-alpha: TNF-α; Prostaglandin E2: PGE2; Inducible nitric oxide synthase: iNOS; Nonsteroidal anti-inflammatory drugs: NSAIDs; lipopolysaccharide: LPS; The total ion chromatograms: TIC; The liquid chromatography/quadrupole-time of flight: LC/Q-TOF; Nuclear factor-kappa B: NF-κB; Janus kinase-signal transducers and activators of transcription: JAK-STAT. [ABSTRACT FROM AUTHOR]
Yak butter is one of the most important foods for the Tibetan people. Of note, its production yields waste yak milk as a by-product. In this work, waste yak milk protein hydrolysates made via Pepsin hydrolysis were shown to have antimicrobial activity. Furthermore, an innovative method of magnetic liposome adsorption combined with reversed-phase high performance liquid chromatography (RP-HPLC) was developed to screen for and purify the antimicrobial peptides. Two antimicrobial peptides were obtained and their amino acid sequences were determined by N-sequencing, namely Arg-Val-Met-Phe-Lys-Trp-Ala and Lys-Val-Ile-Ser-Met-Ile. The antimicrobial activity spectra of Arg-Val-Met-Phe-Lys-Trp-Ala included Bacillus subtilis, Staphylcoccus aureus, Listeria innocua, Escherichia coli, Enterobacter cloacae and Salmonella paratyphi, while the Lys-Val-Ile-Ser-Met-Ile peptide shows not only bacterial growth inhibition but also of fungi. Haemolytic testing suggested that these two antimicrobial peptides could be considered to have no haemolytic effect at their minimum inhibitory concentrations (MICs).
<br>Display Omitted<br> Two new phenolic acids (<b>1</b>⿿<b>2</b>) were isolated from the aerial parts of <b>Asterothamnus centrali-asiaticus</b>. Five knownphenolic acids (<b>3</b>⿿<b>7</b>) were also obtained from the title plant. <b>1</b>⿿<b>7</b> were evaluated for their anti-oxidant activity. <b>1</b>⿿<b>7</b> showed anti-oxidant activity with IC50 values ranging from 7.65 to 22.44 μg/mL.<br>Two new phenolic acids 2-hydroxy-5-[(6⿲-<b>O</b>-(<b>E</b>)-caffeoyl)-β-d-glucopyranosyl]-oxybenzoic acid (<b>1</b>) and 2-hydroxy-5-[(3⿲-<b>O</b>-(<b>E</b>)-caffeoyl)-β-d-glucopyranosyl]-oxybenzoic acid (<b>2</b>) were isolated from the aerial parts of <b>Asterothamnus centrali-asiaticus</b>, together with five known ones (<b>3</b>-<b>7</b>). Their structures were elucidated by extensive 1D and 2D NMR studies and HRESIMS investigations. The anti-oxidant activity of the isolates was evaluated through ABTS radical cation decolorization assay. The results showed that all of them exhibited anti-oxidant activity, and compound <b>7</b> was the most active compound with an IC50 value of 7.65 μg/mL.
The young leaves and shoots of Sibiraea laevigata, known as "Liucha", are used as tea by Tibetans to improve digestion after meals. Long-term consumption of "Liucha" will cause weight loss. In present work, we reported on the isolation and NMR and chemical analysis-based elucidation of seven new sorbitol O-caffeic acid ester derivatives named sorbitol esters A-G (1-7) and eighteen known phenolic compounds from S. laevigata. All of the isolates were evaluated for their antioxidant and α-glucosidase inhibitory activities. Among them sorbitol ester A (1), sorbitol ester D (4), sorbitol ester F (6), sorbitol ester G (7), isoferulic acid (15), methyl caffeate (18), trans-p-hydroxycinnamic acid (19), and kaempferol 3-O-β-d-(6″-E-p-coumaroyl)-glucopyranoside (25) showed more potent α-glucosidase inhibitory activity than the clinical drug acarbose.
• <b>Saxifraga tangutica</b> Engl. is a promising source of antioxidants against DPPH and FRAP. • The 50% ethanol extract of S. <b>tangutica</b> showed strong antioxidative activity against DPPH and FRAP. • Eight phenols were isolated from S. <b>tangutica</b>; all of the compounds are reported for the first time from this plant. • The antioxidative S. <b>tangutica</b> extracts and isolated phenols supports the antioxidant of this plant.<br><b>Saxifraga tangutica</b> Engl., is a medicinal herb that grows on the Qinghai-Tibet Plateau. Extracts and phenols from the Qinghai population have been subjected to antioxidative assays against DPPH radical-scavenging and reducing power (FRAP). The 50% ethanol extract showed strong antioxidative activity against DPPH and FRAP, with IC50 ± SEM [μg/mL] values of 9.38 ± 0.46 and 15.46 ± 0.52, respectively. The antioxidative activity-guided fractionations were performed according to the DPPH and FRAP screening results. Fourteen fractions from the 50% ethanol extract showed dissimilar antioxidative activity against DPPH and FRAP of 8.16 ± 0.76 ∼ 38.42 ± 0.58 μg/mL and 13.22 ± 0.68 ∼ 61.47 ± 0.49 μg/mL. The chemical assay-guided separation of the active fractions (fractions 3, 6, 7 and 8) led to eight phenols: protocatechuic aldehyde (<b>1</b>), ethyl gallate (<b>2</b>), rhododendrin (<b>3</b>), <b>p</b>-hydroxyacetophenone (<b>4</b>), rhododendrol (<b>5</b>), protocatechuic acid ethyl ester (<b>6</b>), frambinone (<b>7</b>) and ethylparaben (<b>8</b>). All phenols are reported here for the first time from <b>S. tangutica</b> Engl. Protocatechuic aldehyde (<b>1</b>), ethyl gallate (<b>2</b>), rhododendrin (<b>3</b>) and protocatechuic acid ethyl ester (<b>6</b>) showed strong antioxidative activities (IC50 ± SEM [mM] between 8.79 ± 0.15 and 4.25 ± 0.47 and between 6.15 ± 0.48 and 2.83 ± 0.49) against DPPH and FRAP.
The first phytochemical investigation on the roots of <b>Ligularia purdomii</b> led to the isolation and identification of 18 compounds, including two eremophilane sesquiterpenoids (<b>1</b> and <b>2</b>), three benzofuran derivatives (<b>3</b>-<b>5</b>), a triterpenoid (<b>6</b>), two steroids (<b>7</b> and <b>8</b>), nine phenolic components (<b>9</b>-<b>17</b>), and a monofatty glyceride (<b>18</b>). The structural elucidation of the isolated compounds was performed by spectroscopic data and comparison with the literature. Compounds (−)-syringaresinol (<b>11</b>), scopoletin (<b>13</b>), 3,5-dimethoxy-4-hydroxy-benzaldehyde (<b>14</b>), and glycerol monolinoleate (<b>18</b>) have not been recorded in <b>Ligularia</b> genus previously. The chemotaxonomic significance of these isolated compounds has been summarized.<br>• First phytochemical investigation on <b>L. purdomii.</b> • 18 compounds were identified from the acetone extract of <b>L. purdomii.</b> • Four compounds were reported from the genus <b>Ligularia</b> for the first time. • The results had important significance for chemotaxonomy of <b>L. purdomii.</b>
A phytochemical investigation of <b>Saxifraga tangutica</b> led to the isolation of 11 compounds, including eight diarylheptanoids (<b>1</b>-<b>6</b>, <b>10</b> and <b>11</b>) and three phenylpropanoids (<b>7</b>-<b>9</b>). The chemical structures were established by extensive analysis of their MS and NMR spectroscopic data or comparison with literature data. In the present research, we report the isolated compounds <b>1</b>-<b>11</b>, for the first time, in the species <b>S. tangutica</b>. Moreover, compounds <b>1</b>, <b>2</b> and <b>4</b>-<b>11</b> have not been reported from any species in Saxifragaceae family. Furthermore, we discuss the chemotaxonomic significance of the isolated compounds.<br>• Eight diarylheptanoids and three phenylpropanoids have been isolated from <b>Saxifraga tangutica.</b> • Compounds <b>1</b>-<b>11</b> are firstly reported in the species <b>Saxifraga tangutica.</b> • Compounds <b>1</b>, <b>2</b> and <b>4</b>-<b>11</b> are firstly isolated from genus <b>Saxifraga</b> or family Saxifragaceae.
The separation of high-purity compounds from traditional Tibetan medicines plays an important role in investigating their bioactivity. Nevertheless, it is often quite difficult to isolate compounds with high purity because of the complexity of traditional Tibetan medicines. In this work, an offline two-dimensional reversed-phase preparative method was successfully developed for the separation of high-purity compounds from Oxytropis falcata. Based on the analysis results, an ODS C18 prep column was used for first-dimensional preparation, and 14.8 g of the crude sample was separated into five fractions with a recovery of 74.6%. Then, an XAqua C18 prep column was used to isolate high-purity compounds in the second-dimensional preparation because its separation selectivity is different with the ODS C18 stationary phase. As a result, eight compounds in the crude sample were isolated in more than 98% purity. This is the first report of trans-cinnamic acid (1) and trifolirhizin (2) from Oxytropis falcata. This method has the potential to be an efficient separation method of high-purity compounds from Oxytropis falcata and it shows great promise for the separation of high-purity compounds from complex samples.
BACKGROUND: Our previous studies on Asterothamnus centrali-asiaticus Novopokr. (ACN) and Arenaria kansuensis Maxim. (AKM) had led to the isolation of some phytochemical constituents and evaluation of anticonvulsant effect based on their extracts. ACN and AKM have been widely used in traditional Tibetan herbs for neuropsychiatric diseases and cardiopulmonary disorders.PURPOSE: The purpose is to investigate structure-activity relationships of flavonoids isolated from ACN and AKM, for binding to the benzodiazepine site (BZ-S) of γ-aminobutyric acid type A (GABAA) receptor complex, and to search for anticonvulsant compounds without undesirable effects such as myorelaxation and sedation.
STUDY DESIGN AND METHODS: The affinities of these flavonoids for the BZ-S of GABAA receptors were determined by [3H]flunitrazepam binding to mouse cerebellum membranes in vitro. And the anticonvulsant, myorelaxant and sedative effects were determined by pentylenetetrazol (PTZ)-induced seizure and electrogenic seizure protection, rotarod test and locomotor activity test, respectively.
RESULTS: Fifteen and thirteen flavonoids were isolated from ACN and AKM, respectively. Structure-activity relationships analysis indicated that 6-and/or 8-OMe flavones exhibited the most potent binding affinity to GABAA receptors. Furthermore, 2',4',5,7-tetrahydroxy-5',6-dimethoxyflavone (DMF, IC50 value of 0.10 μM), a flavone isolated from ACN, presented high anticonvulsant activity against chemical-induced seizures and electrogenic seizures, without myorelaxation and sedation.
CONCLUSION: This study suggested that these flavones, especially DMF, are new BZ receptor ligands and prospective therapeutic candidates for seizures.
<br>Display Omitted<br>• The effect of organic sample solvents in SCX mode were systematically studied. • Organic sample solvents affect the separation efficiency in SCX mode seriously. • Elution strength of organic solvents affect efficiency of later-eluted analyte. • Retention of organic solvents affected efficiency of earlier-eluted analyte. • The results can be used for the optimization of SCX methods.<br>This study investigated the influence of organic sample solvents on separation efficiency of basic compounds under strong cation exchange (SCX) mode. The mixtures of acidic aqueous solution and organic solvent such as acetonitrile, ethanol, methanol and dimethyl sulfoxide (DMSO) were tested as sample solvents. For later-eluting analytes, the increase of sample solvent elution strength was responsible for the decrease of separation efficiency. Thus, sample solvents with weak elution strength could provide high separation efficiencies. For earlier-eluting analytes, the retention of organic sample solvents was the main factor affecting separation efficiency. Weakly retained solvents could provide high separation efficiency. In addition, an optimized approach was proposed to reduce the effect of organic sample solvent, in which low ionic solvent was employed as initial mobile phase in the gradient. At last, the analysis of impurities in hydrophobic drug berberine was performed. The results showed that using acidic aqueous methanol as sample solvents could provide high separation efficiency and good resolution (<b>R</b> > 1.5).
Nitraria tangutorum Bor., having edible berries, is valued for reputed health benefits in Qinghai-Tibet plateau. The phytochemical research on the fruit juice of N. tangutorum led to the isolation of twenty-six compounds including five new compounds, tangutorids A-D (1, 2, 3a, and 3b), and (3E,5E)-7-O-β-glucosyl-4-(2-methoxy-2-oxoethyl)hepta-3,5-dienoic acid (15). The structures of these compounds were elucidated through comprehensive spectroscopic analyses. Tangutorids A-F were the first examples of glucose-derived β-carbolines from natural products. The biogenetic pathways of 1-8 were proposed to involve Pictet-Spengler reactions and described starting from the co-isolated tryptophan (10) and corresponding aldehydes. All isolates were evaluated for their antioxidant and α-glucosidase inhibitory activities. Compounds 21, 22, and 24 showed antioxidant activity with SC50 values ranging from 12.2±1.9 to 30.4±2.7μg/mL, and compound 1 showed strong α-glucosidase inhibitory effect with IC50 value of 63.3±4.6μg/mL.
<br>Display Omitted<br>• A new coupled method of stable isotope-labeling derivatization with UA-DLLME was reported. • Simultaneous determination of multiple neurotransmitters with UHPLC-MS/MS. • Heavy labeled d3-MASC standards were used as the internal standards for quantification. • The method was sensitive, accurate and low matrix effect. • Application for neurotransmitters dynamic changes in rats brain microdialysates.<br>In this work, for the first time, a new hyphenated technique of stable isotope-labeling derivatization-ultrasound-assisted dispersive liquid-liquid microextraction has been developed for the simultaneous determination of monoamine neurotransmitters (MANTs) and their biosynthesis precursors and metabolites. The developed method was based on ultra high performance liquid chromatography tandem mass spectrometry detection using multiple-reaction monitoring mode. A pair of mass spectrometry sensitizing reagents, d0-10-methyl-acridone-2-sulfonyl chloride and d3-10-methyl-acridone-2-sulfonyl chloride, as stable isotope probes was utilized to facilely label neurotransmitters, respectively. The heavy labeled MANTs standards were prepared and used as internal standards for quantification to minimize the matrix effects in mass spectrometry analysis. Low toxic bromobenzene (extractant) and acetonitrile (dispersant) were utilized in microextraction procedure. Under the optimized conditions, good linearity was observed with the limits of detection (S/N > 3) and limits of quantification (S/N > 10) in the range of 0.002-0.010 and 0.015-0.040 nmol/L, respectively. Meanwhile, it also brought acceptable precision (4.2-8.8%, peak area RSDs %) and accuracy (recovery, 96.9-104.1%) results. This method was successfully applied to the simultaneous determination of monoamine neurotransmitters and their biosynthesis precursors and metabolites in rat brain microdialysates of Parkinson's disease and normal rats. This provided a new method for the neurotransmitters related studies in the future.
A new diarylheptanoid, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-6-Oacetylglucoside (<i>1</i>), together with two known diarylheptanoids, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-glucopyranoside (<i>2</i>) and hirsutanonol (<i>3</i>), were isolated from Saxifraga tangutica. The structures of <i>1-3</i> were elucidated using 1D and 2D NMR spectral data, including high-resolution mass spectra (HR-ESI-MS). It was found that the new compound was acetyl-substituted (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-glucopyranoside.
A new isocoumarin, along with 10 known compounds, was isolated from the aerial parts of Aconitum gymnandrum. Their structures were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Among the known compounds, compound 11 was obtained as a natural product for the first time, which was previously reported as a synthetic product. In addition, compounds 1-5, 7 and 9 were tested for their cytotoxicity against four human cancer cell lines. The results showed that compounds 3, 4 and 7 displayed cytotoxicity against lung cancer A549 and gastric cancer MGC80, respectively, whereas 5 and 9 showed selective cytotoxicity against hepatocellular carcinoma HepG2.
<br>Display Omitted<br>• Two new monoterpenes named sibiscolactons A and B (<b>1</b> and <b>2</b>) were isolated from <b>Sibiraea laevigata</b>. • New compounds’ absolute configurations were established by electronic circular dichroism (ECD) calculations. • Eight known phenylpropanoids (<b>3</b>-<b>10</b>) were also obtained from the title plant. • <b>1</b>-<b>10</b> were evaluated for their cytotoxic activity. • Compound <b>3</b> displayed moderate cytotoxicity with IC50 values ranging from 10.8 to 49.2 μg mL−1.<br>Chemical investigation of the ethanol extract of the stalks and infructescence of <b>Sibiraea leavigata</b> led to the isolation of two new monoterpenes named (4<b>R</b>)-2-(2-hydroxy-4-methyl-3-pentenyl)furan-2(5<b>H</b>)-one (<b>1</b>) and (2<b>R</b>,4<b>R</b>)-2-(2-hydroxyethyl)-4-(2-methyl-1-propenyl)furan-5<b>H</b>-2-one (<b>2</b>) along with eight known phenylpropanoids (<b>3-10</b>). Their structures were established on the basis of the interpretation of spectroscopic data and electronic circular dichroism (ECD) calculations. In addition, all of these isolates were evaluated for their cytotoxic activity. The results showed that compound <b>3</b> displayed moderate cytotoxicity with IC50 values ranging from 10.8 to 49.2 μg mL−1 against five cell lines. While <b>1</b> showed selective promotion effects on proliferation of gastric cancer MGC803 and RSC96 cell lines.
Phytochemical investigation on <b>Asterothamnus centrali-asiaticus</b> afforded four new sesquiterpenes, asterothamnones A-D (<b>1</b>-<b>4</b>), and three new benzofuran derivatives (<b>5</b>-<b>7</b>) together with ten known compounds (<b>8</b>-<b>17</b>). Their structures were elucidated using 1D and 2D NMR and X-ray diffraction analyses. Compounds <b>1</b>-<b>4</b> were verified to be unusual eudesmane sesquiterpenes possessing 4,6-dien-3-one or 1,4,6-triene-3-one conjugated system. The absolute configurations of compounds <b>1</b>-<b>8</b> were established by means of calculated electronic circular dichroism (ECD). Furthermore, all isolates were evaluated for their cytotoxic and anti-oxidant activities. Results showed that <b>10</b>, <b>12</b> and, <b>14</b> exhibited cytotoxic activity against HepG2 cancer cells and <b>14</b> displayed cytotoxicity against MGC-803 cancer cells. Compounds <b>10</b> and <b>17</b> showed anti-oxidant effect.<br><br>Display Omitted
Traditional Tibetan medicine provides an abundant source of knowledge on human ailments and their treatment. As such, it is necessary to explore their active single compounds used to treat these ailments to discover lead compounds with good pharmacologic properties. In this present work, animal medicine, Osteon Myospalacem Baileyi extracts have been separated using a two-dimensional preparative chromatographic method to obtain single compounds with high purity as part of the following pharmacological research. Five high-purity cyclic dipeptides from chromatography work were studied for their dihydroorotate dehydrogenase inhibitory activity on recombinant human dihydroorotate dehydrogenase enzyme and compound Fr. 1-4 was found to contain satisfying inhibition activity. The molecular modeling study suggests that the active compound Fr. 1-4 may have a teriflunomide-like binding mode. Then, the energy decomposition study suggests that the hydrogen bond between Fr. 1-4 and Arg136 can improve the binding mode to indirectly increase the van der Waals binding energy. All the results above together come to the conclusion that the 2, 5-diketopiperazine structure group can interact with the polar residues well in the active pocket using electrostatic power. If some proper hydrophobic groups can be added to the sides of the 2, 5-diketopiperazine group, it is believed that better 2, 5-diketopiperazine dihydroorotate dehydrogenase inhibitors will be found in the future.
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