Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Jun Dang is active.

Publication


Featured researches published by Jun Dang.


International Journal of Biological Macromolecules | 2013

Optimization of polysaccharides from Lycium ruthenicum fruit using RSM and its anti-oxidant activity

Zenggen Liu; Jun Dang; Qilan Wang; Minfeng Yu; Lei Jiang; Lijuan Mei; Yun Shao; Yanduo Tao

Dynamic microwave-assisted extraction (DMAE) technique was employed for the extraction of polysaccharides from Lycium ruthenicum (LRP). The extracting parameters were optimized by using three-variable-three-level Box-Behnken design and response surface methodology (RSM) based on the single-factor experiments. RSM analysis indicated good correspondence between experimental and predicted values. The optimum extraction parameters for the yield of polysaccharide were ratio of water to raw material 31.5 mL/g, extracting time 25.8 min and microwave power 544.0 W. Polysaccharide was analyzed by chemical methods and Fourier-transform infrared (FT-IR). The antioxidant activities of LRP were investigated including scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide and free radicals of superoxide anion in vitro. The results of antioxidant activity exhibited LRP had the potential to be explored as novel natural antioxidant for using in functional foods or medicine.


Journal of Separation Science | 2016

Two-dimensional hydrophilic interaction chromatography × reversed-phase liquid chromatography for the preparative isolation of potential anti-hepatitis phenylpropanoids from Salvia prattii.

Jun Dang; Yun Shao; Jian-Qiang Zhao; Lijuan Mei; Yanduo Tao; Qilan Wang; Li Zhang

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.


Journal of Chromatography B | 2017

Two-dimensional chromatography based on on-line HPLC-DPPH bioactivity-guided assay for the preparative isolation of analogue antioxidant compound from Arenaria kansuensis.

Yulei Cui; Na Shen; Xiang Yuan; Jun Dang; Yun Shao; Lijuan Mei; Yanduo Tao; Qilan Wang; Zenggen Liu

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 800mg 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.


Journal of Separation Science | 2017

Anti-inflammatory bioactive equivalence of combinatorial components β-carboline alkaloids identified in Arenaria kansuensis by two-dimensional chromatography and solid-phase extraction coupled with liquid–liquid extraction enrichment technology

Yulei Cui; Na Shen; Jun Dang; Lijuan Mei; Yanduo Tao; Zenggen Liu

Bioactive equivalent combinatorial components play a critical role in herbal medicines. However, how to discover and enrich them efficiently is a question for herbal pharmaceuticals researchers. In our work, a novel two-dimensional reversed-phase/hydrophilic interaction high-performance liquid chromatography method was established to perform real-time components trapping and combining for preparation and isolation of coeluting components. Arenaria kansuensis was taken as an example, and solid-phase extraction coupled with liquid-liquid extraction as a simple and efficient method for enriching trace components, reversed phase column coupled with hydrophilic interaction liquid chromatography XAmide column as two-dimensional chromatography technology for isolation and preparation of coeluting constituents, enzyme-linked immune-sorbent assay as bio-guided assay, and anti-inflammatory bioactivity evaluation for bioactive constituents. A combination of 12 β-carboline alkaloids was identified as anti-inflammatory bioactive equivalent combinatorial components from A. kansuensis, which accounts for 1.9% w/w of original A. kansuensis. This work answers the key question of which are real anti-inflammatory components from A. kansuensis and provides a fast and efficient approach for discovering and enriching trace β-carboline alkaloids from herbal medicines for the first time. More importantly, the discovery of bioactive equivalent combinatorial components could improve the quality control of herbal products and inspire a herbal medicine based on combinatorial therapeutics.


Natural Product Research | 2016

A new isocoumarin from the aerial parts of Aconitum gymnandrum.

Jian-Qiang Zhao; Yan-Ming Wang; Shuo Wang; Jun Dang; Yan-Ping Shi; Lijuan Mei; Yanduo Tao

Abstract 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.


Chemistry of Natural Compounds | 2017

Chemical Constituents of Incarvillea compacta

Jian-Qiang Zhao; Yan-Ming Wang; Jun Dang; Qilan Wang; Yun Shao; Lijuan Mei; Yanduo Tao

Incarvillea Juss. is notable for being a temperate and herbaceous genus of the primarily tropical and woody family Bignoniaceae. It is composed of 16 species, and most of the species occur in the Himalayas and S. W. China, whereas, a number of species are distributed through eastern and central Asia and into Mongolia [1, 2]. Many species of this genus are used as an ethnobotanical herb in China. For example, I. arguta has been widely used as a herbal medicine of the Yi nationality (an ethnic minority group of China) to treat hepatitis and diarrhea in China, and I. sinensis has been used in traditional Chinese medicine as a drug (“Tougucao”) to treat rheumatism and to relieve pain [3, 4]. Incarvillea compacta Maxim. is distributed in gravel slopes and grass brush, at 2600–4100 meters above sea level, in Gansu, Qinghai, Yunnan, and Tibet of China [5]. It is one of the four plant resources of red “Ou-Qv,” a common Tibetan medicine, commonly used for treating jaundice and stomachache, and especially as a major component in the prescription for otopathy like tympanitis and suppurative otitis media [6]. Previous work has been carried out on estimating the distribution area of I. compacta in Tibet, and the results showed that the distribution area of I. compacta was 4.75 105 km2, and the greatest resource amount of I. compacta was 2.17 105 tons in Tibet, which illustrated its abundant resources in Tibet [7]. However, its constituents are so far unknown. The aim of the study was to investigate the chemical constituents of I. compacta Maxim. through various chromatographic and spectroscopic methods. This study resulted in the identification of 23 known compounds, including five phenylpropanoid glycosides, three flavonoids, three iridoid glycosides, five triterpenes, two steroids, and four other compounds. The known compounds were identified as isoacteoside (1) [8], epimeridinoside A (2) [9], plantainoside C (3) [10], acteoside (4) [11], echinacoside (5) [12], citrusin C (6) [13], apigenin (7) [14], luteolin (8) [15], quercetin-3-O-L-(2 -galloyl)-arabinopyranoside (9) [16], sweroside (10) [17], swertiamarin (11) [18], 5-deoxystansioside (12) [19], -amyrin (13) [20], ursolic acid (14) [21], pololic acid (15) [22], roburic acid (16) [23], lupeol (17) [24], -sitosterol (18) [25], daucosterol (19) [26], caffeic acid (20) [27], 2,4-dihydroxy-6-methoxy-3-methylacetophenone (21) [28], palmitic acid (22) [29], and methyl gallate (23) [30] by comparison with authentic samples and by comparison of their spectroscopic and physical data with those previously reported. All of the isolates from Incarvillea compacta Maxim. were reported for the first time. The whole plant of Incarvillea compacta was bought from Lekang medicine market, Xining, Qinghai Province, P. R. China and identified by Prof. Li-Juan Mei (Northwest Institute of Plateau Biology, Chinese Academy of Science). The air-dried whole plants (5 kg) of I. compacta were extracted with 85% ethanol three times, each time for 3 h under reflux at 70 C. After concentration in vacuum, the combined extract (356 g) was suspended in H2O and partitioned with petroleum ether, EtOAc, and n-BuOH successively to give dried petroleum ether (50 g), EtOAc (118 g), n-BuOH (78 g), and H2O (106 g) fractions. The EtOAc soluble fraction was subjected to silica gel (200–300 mesh) column chromatography and eluted with a gradient solvent system of petroleum ether–EtOAc (5:1–1:1) to give six fractions (E1–E6). Compound 18 was crystallized from E3 and recrystallized to afford compound 18 (142 mg). The residue from E3 was subjected to CC over silica gel (CHCl3–Me2CO, 20:1–9:1) repeatedly to afford compounds 13 (19.2 mg) and 17 (50 mg). Compound 22 was crystallized from E4 and recrystallized to afford compound 22 (150 mg). The residue from E4 was subjected to column chromatography


Chemistry of Natural Compounds | 2017

A New Diarylheptanoid from Saxifraga tangutica

Jun Dang; Jian-Qiang Zhao; Yanduo Tao; Shuo Wang; Yun Shao; Lijuan Mei; Qilan Wang; Li Zhang

A new diarylheptanoid, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-6-Oacetylglucoside (1), together with two known diarylheptanoids, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-glucopyranoside (2) and hirsutanonol (3), were isolated from Saxifraga tangutica. The structures of 1–3 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.


Pharmacognosy Magazine | 2018

Anti-inflammatory activity of total alkaloids from Hypecoum leptocarpum hook. f. et Thoms

Yun Shao; Yanduo Tao; Huaixiu Wen; Lei Jiang; Defang Zhang; Xiang Yuan; Jun Dang; Lijuan Mei

Background: Puerariae Lobatae Radix is widely used in the pharmaceutical, food, and cosmetic industries. For these applications, when grading roots according to diameter, thick roots are always considered to be of better quality. Objective: The objective of this study is to qualitative and quantitative analysis of isoflavonoids profiling in various tissues of P. lobata roots. Materials and Methods: Ultraperformance liquid chromatography quadrupole/time-of-flight-mass spectrometry (UPLC-QTOF/MS) and high-performance liquid chromatography separation and ultraviolet-visible detection were used to identify and profile the isoflavonoids detected in various tissues of P. lobata roots. Results: Consequently, 82 peaks were detected by UPLC-QTOF/MS, and 28 isoflavonoid compounds were identified in the various tissue samples. According to the results of this study, the thick roots of P. lobata are of better quality for medical use than the thin ones. The fine roots and the periderm of roots contained slightly lower isoflavonoid abundances. The results indicated that isoflavonoids, particularly puerarin, mainly accumulated in the xylem and phloem. Conclusions: This study provides a new and practical method for evaluating the quality of P. lobatae Radix. Abbreviations used: ANOVA: One-way analysis of variance; CNKI: Chinese National Knowledge Infrastructure; HPLC-UV: High performance liquid chromatography separation and ultraviolet-visible detection; PPRC: Pharmacopoeia of the Peoples Republic of China; RSD: Relative standard deviation; UPLC-QTOF/MS: Ultraperformance liquid chromatography quadrupole/time-of-flight-mass spectrometry.


Natural Product Research | 2018

8-isopentenyl isoflavone derivatives from the whole herb of Sphaerophysa salsula

Lijin Jiao; Weidong Wang; Yanduo Tao; Yun Shao; Lijuan Mei; Zenggen Liu; Qilan Wang; Jun Dang

Abstract 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.


Molecules | 2018

Efficient Separation of Four Antibacterial Diterpenes from the Roots of Salvia Prattii Using Non-Aqueous Hydrophilic Solid-Phase Extraction Followed by Preparative High-Performance Liquid Chromatography

Jun Dang; Yulei Cui; Jinjin Pei; Huilan Yue; Zenggen Liu; Weidong Wang; Lijin Jiao; Lijuan Mei; Qilan Wang; Yanduo Tao; Yun Shao

An efficient preparative procedure for the separation of four antibacterial diterpenes from a Salvia prattii crude diterpenes-rich sample was developed. Firstly, the XION hydrophilic stationary phase was chosen to separate the antibacterial crude diterpenes-rich sample (18.0 g) into three fractions with a recovery of 46.1%. Then, the antibacterial fractions I (200 mg), II (200 mg), and III (150 g) were separated by the Megress C18 preparative column, and compounds tanshinone IIA (80.0 mg), salvinolone (62.0 mg), cryptotanshinone (70.0 mg), and ferruginol (68.0 mg) were produced with purities greater than 98%. The procedure achieved large-scale preparation of the four diterpenes with high purity, and it could act as a reference for the efficient preparation of active diterpenes from other plant extracts.

Collaboration


Dive into the Jun Dang's collaboration.

Top Co-Authors

Avatar

Yanduo Tao

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

Lijuan Mei

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

Yun Shao

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

Qilan Wang

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

Zenggen Liu

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

Jian-Qiang Zhao

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

Li Zhang

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

Weidong Wang

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

Lijin Jiao

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

Xiang Yuan

Chinese Academy of Sciences

View shared research outputs
Researchain Logo
Decentralizing Knowledge