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F3e (242 mg) with Sephadex LH-20 (EtOH) and RP semipreparative HPLC (24% MeOH in H SB 2 sb O) afforded compound B 6 b (3 mg). F3f (626 mg) with Sephadex LH-20 (MeOH) and RP semipreparative HPLC (27% MeOH in H SB 2 sb O) afforded compound B 5 b (4 mg). F2a (1.1 g) with Sephadex LH-20 (MeOH) (3 × 150 cm) yielded subfractions and was followed by RP semipreparative HPLC (33% MeOH in H SB 2 sb O) purification to yield B 10 b (2 mg). Subfraction F4b3 (243 mg) was then purified by RP semipreparative HPLC (42% MeOH in H SB 2 sb O) to yield B 3 b (7 mg) and B 4 b (2 mg). [Extracted from the article]

The lack of suitable chromatographic purification methods makes it a challenge to effectively isolate the chemical components of traditional Tibetan medicines. Ribes himalense is a rarely studied Tibetan medicine, reputed to have free radical‐scavenging effects. In the present work, we utilized it as a model herb to highlight an approach for the separation of 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors via medium‐pressure chromatography and two‐dimensional reversed‐phase/reversed‐phase interaction liquid chromatography under the guidance of an online high‐performance liquid chromatography‐1,1‐diphenyl‐2‐picrylhydrazyl assay. Finally, we obtained two free radical inhibitors (>95% purity) from the R. himalense extract. This is the first report of the rapid isolation of these free radical inhibitors from R. himalense. This method can be useful in quality standard assessment and further pharmacological activity research, and may be used as a reference for the composition research of various natural products. [ABSTRACT FROM AUTHOR]

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]

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. [ABSTRACT FROM AUTHOR]

Traditional Tibetan medicine is important for discovery of drug precursors. However, knowledge of the chemical composition of traditional Tibetan medicines is very limited due to the lack of appropriate chromatographic purification methods. In the present work, Salvia prattii was taken as an example, and an off-line hydrophilic interaction liquid chromatography/reversed-phase liquid chromatography preparative method was developed for the purification of phenylpropanoids with high purity from a crude sample of Salvia prattii. Based on the separation results of four different chromatographic stationary phases, the first-dimensional preparation was performed on an XAmide preparative column with the crude sample concentration of 62.0 mg/mL, and five main fractions were obtained from the 12.4 g crude sample with a recovery of 54.8%. An XCharge C18 preparative column was applied in the second-dimensional preparation to further isolate the phenylpropanoids from the redissolved first-dimensional fractions with concentration of approximately 50.0 mg/mL. The purities of the phenylpropanoids isolated from the crude sample of Salvia prattii were higher than 98%, indicating that the method was efficient for the purification of phenylpropanoids with high purity from Salvia prattii. Additionally, this method showed great potential in the preparation of phenylpropanoids and can serve as a good example for the purification of phenylpropanoids from other plant materials. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Animal medicine is an important part in traditional Tibetan medicine. However, information about the chemical composition of animal medicine is very limited, and there is a lack of comprehensive chromatographic purification methods. In the present work, animal medicine Osteon Myospalacem Baileyi was taken as an example and a novel two-dimensional preparative chromatographic method was established for the preparation of single compounds with high purity from the extract of Osteon Myospalacem Baileyi. The first-dimension preparation was carried on a DAISO Silica prep column, and ten fractions were obtained from the 112.3 g crude sample within 12 injections. A diol prep column used in nonaqueous mobile phase was selected for the second-dimension preparation. The purity of the compounds isolated from the crude extract was >98%, which indicated that the method built in this work was efficient to manufacture single compounds of high purity from the extract of Osteon Myospalacem Baileyi. Additionally, this method showed great potential in the purification of weakly polar chemicals and it could act as a good example in the purification of other traditional animal medicines. [ABSTRACT FROM AUTHOR]

Pterocephalus hookeri, as a kind of popular traditional Tibetan medicine, is reputed to treat inflammatory related diseases. In the present work, a cyclooxygenase-2 functionalized affinity solid-phase extraction HPLC system was developed and combined with preparative-HPLC for rapidly screening and separating cyclooxygenase-2 ligand from P. hookeri extracts. Firstly, ligands of cyclooxygenase-2 were screened from extracts by affinity solid-phase extraction HPLC system. Then directed by the screening results, the recognized potential active compounds were targeted separated. As a result, the major cyclooxygenase-2 inhibitor of P. hookeri was obtained with a purity of >95%, which was identified as sylvestroside I. To test the accuracy of this method, the anti-inflammatory activity of sylvestroside I was inspected in lipopolysaccharide-induced RAW 264.7 cells. The results show that sylvestroside I significantly suppressed the release of prostaglandin E2 with dose-dependent, which was in good agreement with the screening result of the affinity solid-phase method. This method of integration of screening and targeted separation proved to be very efficient for the recognition and isolation of cyclooxygenase-2 inhibitors from natural products. [ABSTRACT FROM AUTHOR]

Traditional Tibetan medicine (TTM) has been valuable for the identification of new therapeutic leads. Nevertheless, reports about the chemical constituents of TTM are meager owing to the lack of suitable purification techniques. In this study, an off-line two-dimensional reversed-phase/hydrophilic interaction liquid chromatography (2D RP/HILIC) technique guided by on-line HPLC-DPPH has been established for the isolation of pure antioxidants from the extract of Dracocephalum heterophyllum . According to the chromatographic recognition outcome of the HPLC-DPPH system, the first-dimensional (1D) separation on the Megress C18 preparative column yielded 6 antioxidative fractions (61.4% recovery) from the ethyl acetate fraction (6.1 g). In the second-dimensional (2D) separation, a HILIC XAmide preparative column was employed. In total, 8 antioxidants were isolated from D. heterophyllum with a purity of >95%, which indicated the efficiency of the developed method to prepare antioxidative compounds with high purity from plant extracts. In addition, this method was highly efficient for the preparation of structural analogues of the antioxidative polyphenols and could be applied for the purification of structural analogues from other resources. [ABSTRACT FROM AUTHOR]

Traditional Tibetan medicine is important for discovery of drug precursors. However, information about the chemical composition of traditional Tibetan medicine is very limited due to the lack of appropriate chromatographic purification methods. In the present work, A. kansuensis was taken as an example and a novel two-dimensional reversed-phase/hydrophilic interaction liquid chromatography(HILIC) method based on on-line HPLC-DPPH bioactivity-guided assay was developed for the purification of analogue antioxidant compounds with high purity from the extract of A. kansuensis . Based on the separation results of many different chromatographic stationary phases, the first-dimensional (1D) preparation was carried on a RP-C18HCE prep column, and 2 antioxidant fractions were obtained from the 800 mg crude sample with a recovery of 56.7%. A HILIC-XAmide prep column was selected for the second-dimensional (2D) preparation. Finally, a novel antioxidant β-carboline Alkaloids (Glusodichotomine AK) and 4 known compounds (Tricin, Homoeriodictyol, Luteolin, Glucodichotomine B) were purified from A. kansuensis. The purity of the compounds isolated from the crude extract was >98%, which indicated that the method built in this work was efficient to manufacture single analogue antioxidant compounds of high purity from the extract of A. kansuensis . Additionally, this method showed great potential in the preparation of analogue structure antioxidant compounds and can serve as a good example for the purification of analogue structure antioxidant carboline alkaloids and flavonoids from other plant materials. [ABSTRACT FROM AUTHOR]