Comparative Study of the Structural Characteristics and Bioactivity of Polysaccharides Extracted from Aspidopterys obcordata Hemsl. Using Different Solvents.

The polysaccharides extracted from Aspidopterys obcordata are thought to have anti-urolithiasis activity in Drosophila kidney stones. This study aimed to assess the effects of different extraction solvents on the yield, chemical composition, and bioactivity of polysaccharides from A. obcordata. A. obcordata polysaccharides were extracted by using four solutions: hot water, HCl solution, NaOH solution, and 0.1 M NaCl. The results revealed that the extraction solvents significantly influenced the extraction yields, molecular weight distribution, monosaccharide compositions, preliminary structural characteristics, and microstructures of polysaccharides. The NaOH solution's extraction yield was significantly higher than the other extraction methods. Vitro antioxidant activity assays revealed that the NaOH solution extracted exhibited superior scavenging abilities towards DPPH and ABTS radicals and higher FRAP values than other polysaccharides. The vitro assays conducted for calcium oxalate crystallization demonstrated that four polysaccharides exhibited inhibitory effects on the nucleation and aggregation of calcium oxalate crystals, impeded calcium oxalate monohydrate growth, and induced calcium oxalate dihydrate formation. The NaOH solution extracted exhibited the most pronounced inhibition of calcium oxalate crystal nucleation, while the hot water extracted demonstrated the most significant suppression of calcium oxalate crystal aggregation. Therefore, it can be inferred that polysaccharides extracted with NaOH solution exhibited significant potential as a viable approach for extracting polysaccharides from stems due to their superior yield and the remarkable bioactivity of the resulting products.

Derivatives of benzamide of the extracts from the bark of Maqian (Zanthoxylum myriacanthum var. pubescens).

Two newly discovered natural derivatives of benzamide, O-Ethyltembamide (1) and N-[(Z)-2-(4-Methoxyphenyl)vinyl]benzamide(2), together with four known compounds, hortiamide (3), N-[(E)-2-(4-Methoxyphenyl)vinyl] benzamide (alatamide) (4), dihydroaltamide (5) and tembamid (6), were isolated from the barks of of Zanthoxylum myriacanthum var. pubescens (Huang) Huang. Their structures were determined on the basis of spectral data. The anti-inflammatory activity of the isolated compounds (1-6) were scanned against NO production in LPS-activated RAW 264.7 macrophages by MTS assay, however no significant activities were observed.

One novel alkaloid from the stems of Tinospora crispa.

The 6-methoxy-cannabisin I (1), a new alkaloid, together with five known compounds oleraisoindole A (2), cannabisin F (3), apigenin (4), syringin (5) and ethyl-syringin (6) were isolated from Tinospora crispa stems. Their structures were identified by the analysis of spectroscopic data. Compound 2 was isolated from T. crispa for the first time. Anti-inflammatory activity of compound 1 was detected against NO production in LPS-activated RAW 264.7 macrophages. However, no activity was observed.

Bioactivity-Guided High Performance Counter-Current Chromatography and Following Semi-Preparative Liquid Chromatography Method for Rapid Isolation of Anti-Inflammatory Lignins from Dai Medicinal Plant, Zanthoxylum acanthopodium var. timbor.

The development of Dai medicine is relatively slow, and Zanthoxylum has great economic and medicinal value. It is still difficult to obtain medicinal components from the low-polarity parts of Zanthoxylum belonging to Dai medicine. In this study, we introduced one simple and quick strategy of separating target compounds from the barks of Z. acanthopodium var. timbor by high-performance countercurrent chromatography (HPCCC) with an off-line anti-inflammatory activity screening mode. The development of this strategy was based on the TLC-based generally useful estimation of solvent systems (GUESS) method and HPCCC in combination. This paper presented a rapid method for obtaining target anti-inflammatory compounds. Three lignins were enriched by HPCCC with an off-line inhibition mode of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophage cells, using petroleum ether-ethyl acetate-methanol-water (3:2:3:2) as the solvent system. The results showed that this method was simple and practical and could be applied to trace the anti-inflammatory components of the low-polarity part in Dai medicine.

Polyoxypregnane Glycosides from Root of Marsdenia tenacissima and Inhibited Nitric Oxide Levels in LPS Stimulated RAW 264.7 Cells.

Six new polyoxypregnane glycosides, marstenacisside F1−F3 (1−3), G1−G2 (4−5) and H1 (6), as well as 3-O-ß-D-glucopyranosyl-(1→4)-6-deoxy-3-O-methyl-ß-D-allopyranosyl-(1→4)-ß-D-oleandropyranosyl-11α,12ß-di-O-benzoyl-tenacigenin B (7), were isolated from the roots of Marsdenia tenacissima. Their structures were established by an extensive interpretation of their 1D and 2D NMR and HRESIMS data. Compounds 1−7 were tenacigenin B derivatives with an oligosaccharide chain at C-3. This was the first time that compound 7 had been isolated from the title plant and its 1H and 13C NMR data were reported. Compounds 4 and 5 were the first examples of C21 steroid glycoside bearing unique ß-glucopyranosyl-(1→4)-ß-glucopyranose sugar moiety. All the isolated compounds were evaluated for anti-inflammatory activity by inhibiting nitric oxide (NO) production in the lipopolysaccharide-induced RAW 264.7 cells. The results showed that marstenacisside F1 and F2 exhibited significant NO inhibitory activity with an inhibition rate of 48.19 ± 4.14% and 70.33 ± 5.39%, respectively, at 40 µM, approximately equal to the positive control (L-NMMA, 68.03 ± 0.72%).

Alpinia hainanensis Rhizome Extract Ameliorates Dextran Sulfate Sodium-Induced Ulcerative Colitis: Active Ingredient Investigation and Evaluation.

Alpinia hainanensis is an important food spice and ethnic medicine in Southwest China. In this study, we found that the EtOAc-soluble fraction (AHE) of the A. hainanensis rhizome ethanol extract could ameliorate dextran sulfate sodium-induced ulcerative colitis (UC). To explore active constituents, five pairs of previously unreported enantiomers (1-5), together with nine known ones (6-14), were obtained. Structural characterization was achieved by comprehensive spectroscopic methods. Compounds 1 and 2 were new curcumin-butyrovanillone hybrids featuring a rare structural fragment of 2,3-dihyrofuran. The anti-inflammatory activities of isolates were evaluated, and the results indicated that compounds (-)-1, (-)-3, 6, 9, 11, and 12 significantly inhibited the nuclear factor-κB signaling pathway. These findings indicate the major active fraction of the A. hainanensis rhizome ethanol extract enriched with diarylheptanoids, flavonoids, phenolics, and their hybrid mixtures, which could be developed as a nutritional and dietary supplement for treating UC.

A novel pentacyclic triterpene from the canes of Uncaria sessilifructus (Rubiaceae).

One novel pentacyclic triterpene, 24-dimethoxymethyl-3ß,6ß,19α- trihydroxy -12-en-28-oic acid (1), along with six known compounds 2-7, were isolated from the canes of Uncaria sessilifructus Roxb. Their structures were determined according to spectroscopic and spectrometric analysis. The anti-inflammatory activities of the isolated compounds (1-7) were scanned against NO production in LPS-activated RAW 264.7 macrophages by MTS assay, however no activities were observed.

Two new monoterpenoid indole alkaloids from Mappianthus iodoides stems.

Two previously unreported monoterpenoid indole alkaloids, 19(20)E-5-carboxymethylvallesiachotamine (1) and 19(20)Z-5-carboxymethylvallesiachotamine (2), along with five known indole alkaloids (3-7) were isolated from Mappianthus iodoides stems. Their structures were characterized by extensive spectroscopic data. Among these isolates, compounds 1 and 2 were the two new Δ19(20) geometric isomers. The anti-inflammatory activities in vitro of all isolated compounds were evaluated using NO assay.[Formula: see text].

Anti-hyperglycaemic effect of labdane diterpenes isolated from the rhizome of Amomum maximum Roxb., an edible plant in Southwest China.

Amomum maximum Roxb. rhizome is a fork medicine mainly used in South and Southeast Asia. In present study, the hypoglycaemic effects of the ethanolic extract of A. maximum rhizome were demonstrated both on α-glucosidase assay in vitro and streptozotocin (STZ)-induced postprandial hyperglycaemia in mice. Furthermore, six labdane diterpenes, amoxanthin A (1), ottensinin (2), coronarin D (3), coronarin D methyl ether (4), isocoronarin D (5), and zerumin (6), were isolated from its ethyl acetate sub-fraction with the guidance of α-glucosidase inhibitory activity. Among these compounds, 2 and 6 exhibited significant inhibitory effect on α-glucosidase, as well as on STZ-induced high postprandial blood glucose levels in mice. Additionally, molecular docking analysis revealed that 2 and 6 could firmly bind to the active sites of α-glucosidase. These results suggest that compounds 2 and 6 are the main anti-hyperglycaemic agents present in A. maximum, which may demonstrate potential beneficial effects in diabetes management.

Development of a strategy for a quick process for separation of volatile compounds in counter-current chromatography: purification of cinnamaldehyde from Cinnamomum cassia by high performance counter-current chromatography.

It is a challenge for many researchers to separate volatile compounds. In this study, we introduce a rapid and efficient method of separating target compound from the twigs of Cinnamomum cassia by high performance counter-current chromatography. Under the bioassay guidance, the total extract exhibited a potential activity against NO production in RAW 264.7 macrophages and the total extract was further separated by high performance counter-current chromatography. Cinnamaldehyde (1) was enriched by counter-current chromatography (CCC) with reversed-phase mode using n-hexane-ethyl acetate-methanol-water (1:1:1:1,v/v/v/v) as the solvent system. Further identification was achieved by high performance liquid chromatography (HPLC).

[Preparation of brazilein from Caesalpinia sappan by high performance countercurrent chromatography].

Brazilein is among the main chemical constituents of Caesalpinia sappan. It has diverse pharmacological activities. Modern pharmacological studies have shown that the compound has antitumor, anti-inflammatory, antibacterial, antioxidant, immunomodulatory, and other pharmacological activities. Brazilein is often used as a stain in various industries. The separation of brazilein by traditional column chromatography will not only result in contamination of the chromatographic column materials, but also lead to loss of the active ingredient. Countercurrent chromatography is an advanced liquid-liquid chromatographic separation technique. It has been widely used for natural product separation and isolation as it offers several advantages, such as low solvent consumption, a highly selective solvent system, and high recoveries. Typical countercurrent chromatography techniques include centrifugal partition chromatography (CPC), high-speed countercurrent chromatography (HSCCC), and high performance countercurrent chromatography (HPCCC). It is well known that choosing a suitable solvent system is vital in countercurrent separation. Therefore, two methods were introduced for choosing a suitable solvent system. One is the generally useful estimation of solvent systems (GUESS) method, which employs thin-layer chromatography (TLC) to identify a suitable solvent system with minimal labor for the rapid purification of target compounds, and another is the Shake-Flash method. The solvent system could be determined by observing the distribution of the sample in the upper and lower phases. Two kinds of solvent systems were screened using the TLC-GUESS and Shake-Flash methods, and tested through the analysis mode of the HPCCC instrument. The results showed that chloroform-methanol-water (4:3:2, v/v/v) was the optimal solvent system for HPCCC separation. A total of 15.2 mg of brazilein and 5.7 mg of caesappanin C were obtained from an ethyl acetate extract with high purities (95.6% and 89.0%, analyzed by HPLC) in one step using the preparation mode of HPCCC, the reversed-phase liquid chromatography mode with the apparatus rotated at 1600 r/min, a flow rate of 10 mL/min, separation temperature of 25℃, and detection wavelength of 285 nm. Their structures were determined by spectroscopic and spectrometric analyses. Brazilein stained the solid packing material in the column and was difficult to elute. The results showed that the use of HPCCC for the separation of brazilein can not only prevent the loss of target active ingredients in Caesalpinia sappan, but also shorten the separation and purification times and improve the operating efficiency. Therefore, HPCCC can be used for the separation and preparation of other pigment compounds in Caesalpinia sappan and other dye plants.

Theoretical and experimental studies on hydrogen migration in dissociative ionization of the methanol monocation to molecular ions H3 + and H2O.

The dissociative ionization processes of the methanol monocation CH3OH+ to H3 + + CHO and H2O+ + CH2 are studied by ab initio method, and hydrogen migration processes are confirmed in these two dissociation processes. Due to the positive charge assignment in dissociation processes, the fragmentation pathways of CH3OH+ to H3 + CHO+ and CH3OH+ to H2O + CH2 + are also calculated. The calculation results show that a neutral H2 moiety in the methanol monocation CH3OH+ is the origin of the formation of H3 +, and the ejection of fragment ions H3 + and H2O+ is more difficult than CHO+ and CH2 + respectively. Experimentally, by using a dc-slice imaging technique under an 800 nm femtosecond laser field, the velocity distributions of fragment ions H3 +, CHO+, CH2 +, and H2O+ are calculated from their corresponding sliced images. The presence of low-velocity components of these four fragment ions confirms that the formation of these ions is not from the Coulomb explosion of the methanol dication. Hence, the four hydrogen migration pathways from the methanol monocation CH3OH+ to H3 + + CHO, CHO+ + H3, H2O+ + CH2, and CH2 + + H2O are securely confirmed. It can be observed in the time-of-flight mass spectrum of ionization and dissociation of methanol that the ion yields of fragment ions H3 + and H2O+ are lower than CHO+ and CH2 + respectively, which is consistent with the theoretical results according to which dissociation from the methanol monocation to H3 + and H2O+ is more difficult than CHO+ and CH2 + respectively.

Countercurrent separation assisted identification of two mammalian steroid hormones in Vitex negundo.

Countercurrent separation (CCS) has been widely used for the separation of high abundance compounds. However, the identification of low abundance compounds, such as mammalian steroid hormones, from natural sources is still a challenging task. A mixture of 14 human steroid hormone reference compounds was prepared for the development of a CCS enrichment strategy. The TLC-based GUESS (Generally Useful Estimate of Solvent Systems) method along with partitioning experiments were implemented to develop a process for the enrichment of these low abundance compounds with CCS. The application of CCS to the steroid hormone enrichment of Vitex negundo extracts was demonstrated by the identification of progesterone and estriol. This method provides a CCS-driven strategy to mine plant sources for low abundance compounds.

Sweet spot matching: A thin-layer chromatography-based countercurrent solvent system selection strategy.

TLC-based strategies were proposed in 1979 (Hostettmann et al.) and 2005 (Friesen & Pauli; GUESS method) to minimize the number of partitioning experiments required for countercurrent separation (CCS) solvent system selection. As semi-empirical approaches, both proposed that the K values defining the sweet spot of optimal CCS corresponded to a matching Rf value range from the silica gel TLC plate developed in the organic phase of a biphasic or a corresponding monophasic solvent system. Despite their simplicity, there has been an absence of theoretical support and a deficiency of reported experimental evidence. The present study explores the theory required to develop correlations between Rf and K. All theoretical models surmise that the optimal Rf value range should be centered at 0.5. In order to validate the feasibility of the concept of matching Rf and K values, 43 natural products and six solvent system families were investigated. Out of 62 correlations, 45 resulted in matched Rf and K values. Based on this study, practical guidelines for the TLC-based prediction strategy are provided. These approaches will equip CCS users with an updated understanding of how to apply the TLC-based solvent system selection strategy to accelerate a targeted selection of CCS conditions.

Chemical constituents and anti-inflammatory activities of Maqian (Zanthoxylum myriacanthum var. pubescens) bark extracts.

In this study, 44 compounds in the petroleum ether extract of Maqian (Zanthoxylum myriacanthum var. pubescens) bark, a traditional Dai herbal medicine, were identified by GC-MS. Major components included 3(2H)-benzofuranone, asarinin and (dimethoxymethyl)-3-methoxy-benzene. A total of 18 compounds were isolated from the ethyl acetate extracts of Maqian bark by column chromatography and identified by chemical and spectral analyses. Rhoifoline B, zanthoxyline dimethoxy derivative, N-nortidine, nitidine, decarine are the major alkaloids. Both the petroleum ether and ethyl acetate extracts showed significant inhibition on NO production, which imply anti-inflammatory activity, in lipopolysaccharide-induced RAW 264.7 cells without cell toxicity. Decarine is the major anti-inflammatory constituent with NO IC50 values of 48.43 µM on RAW264.7 cells. The petroleum ether extract, the ethyl acetate extract and decarine showed anti-inflammatory activities through inhibiting TNF-α and IL-1ß production in lipopolysaccharide-stimulated THP-1 cells without cell toxicity too. Decarine showed anti-inflammatory activity on human colon cells by reducing IL-6 and IL-8 production in TNF-α+IL-1ß-induced Caco-2 cells. These results support the use of Maqian bark as a remedy for enteritis and colitis recorded by Dai medicine in China, and elucidate the major pharmacological compounds in Maqian bark.

Two new lignans from Saururus chinensis.

Two new lignans, (Z)-14-bis(3',4'-dimethoxyphenyl)-2,3-dimethylbut-2-ene-1,4-dione (1), threo-2-methyl-3-oxo-1-(3',4',5'-trimethoxyphenyl)butyl-3″,4″-dimethoxybenzoate (2), together with 15 known derivatives (3-17) were isolated from Saururus chinensis. Their structures were determined on the basis of spectral data, including 1D and 2D NMR experiments and HREIMS spectra. The antitumour activity was screened by MTT assay, compounds 1, 2, 3, 5, 9-11 and 13-15 showed no cytotoxic activity against HL-60, SMMC-7721, A549, MCF-7 and SW480 cell lines.

Quick method for separating target compounds from the bark of Maqian (Zanthoxylum myriacanthum var. pubescens) by high-performance countercurrent chromatography.

Choosing a suitable solvent system for a countercurrent chromatography separation presents a challenge for many researchers. In this study, we introduce a quick method of separating a target compound from the bark of Zanthoxylum myriacanthum var. pubescens by countercurrent chromatography. This method relies on the thin-layer chromatography based generally useful estimation of solvent systems. This paper will present how to quickly choose a suitable solvent system with a thin-layer chromatography based generally useful estimation of solvent systems working chart. O-Methyltembamide (1) was enriched by countercurrent chromatography using n-hexane/ethyl acetate/methanol/water (6:4:6:4) as the solvent system. Further purification was achieved by high-performance liquid chromatography with purities of 98.2% from Z. myriacanthum var. pubescens bark.

A new isoflavone glycoside from Pueraria alopecuroides.

A new isoflavone glycoside, (-)-tuberosin-3-O-ß-D-glucopyranoside (1), along with 10 known compounds 1a-10, was isolated from Pueraria alopecuroides. Their structures were determined on the basis of spectral data including 1D and 2D NMR and HREIMS. These compounds were isolated from this plant for the first time.

One new flavonoid from Oroxylum indicum.

One new flavonoid, 5,6,7-trimethoxyflavone-8-O-ß-D-glucopyranoside (1), along with six known compounds 2-7, was isolated from Oroxylum indicum. Their structures were determined on the basis of spectral data. The antibacterial activities of compounds 1-4 were studied. Compounds 1 and 3 showed medium antibacterial activity against Staphylococcus aureus with MIC/MBC at 32-128 µg/ml.