Min Xu

Bio: Min Xu is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Panax notoginseng & Medicine. The author has an hindex of 25, co-authored 122 publications receiving 1832 citations. Previous affiliations of Min Xu include Nanjing Normal University & Griffith University.

Triterpenoid Acids from Eriobotrya japonica

Abstract: The leaves of Eriobotrya japonica (Thunb.) Lindl. (Rosaceae) were commonly recognized as a traditional Chinese medicine (TCM) to treat various skin diseases and diabetes mellitus. Phytochemical investigations on the leaves of E. japonica revealed their predominant secondary metabolites as triterpenoids including triterpenoid acids [1]. Our previous study showed that triterpenoid acids can decrease the excitability of cortical pyramidal neurons and acts in epilepsy [2]. In our ongoing search for novel and bioactive triterpenoid acids, a detail chemical investigation on the dried leaves of E. japonica was carried out. As a result, 13 triterpenoid acids were isolated and identified on the basis of extensive spectral methods, among which compounds 1, 2, and 4 were isolated from E. japonica for the first time. The air-dried and powdered leaves of E. japonica (10.0 kg) were extracted with MeOH (50 L × 3) under reflux conditions at 70°C, three hours each time. After removal of the organic solvent under reduced pressure, the extract (1.0 kg) was suspended in H2O (4 L), and then successively partitioned with petroleum ether, EtOAc, and n-BuOH. The n-BuOH fraction (100 g) was subjected to silica gel column chromatography (CC) (CHCl3–MeOH, 1:0–0:1) to afford four fractions, Frs.A–D. Fraction A (15 g) was subjected to CC over silica gel (petroleum ether–acetone, 10:1–1:9) and Sephadex LH-20 (MeOH) and then purified by semipreparative HPLC with a C18 column (MeOH–H2O, 1:1–1:0) to afford compounds 1 (17 mg), 2 (16 mg), 3 (40 mg), 4 (30 mg), 5 (200 mg), 6 (150 mg), 7 (100 mg), 8 (32 mg), 9 (20 mg), 10 (23 mg), 11 (25 mg), 12 (11 mg), and 13 (14 mg). 3β-O-cis-p-Coumaroyl-2α-hydroxy-12-ursen-28-oic Acid (1). C39H54O6, white amorphous powder. ESI-MS m/z 617 [M – H]–. 1H NMR (400 MHz, pyridine-d5, δ, ppm, J/Hz): 0.99 (3H, s, Me-23), 0.95 (3H, s, Me-24), 0.94 (3H, s, Me-25), 1.03 (3H, s, Me-26), 1.17 (3H, s, Me-27), 1.07 (3H, d, J = 6.4, Me-29), 1.03 (3H, d, J = 6.1, Me-30), 6.08 (1H, d, J = 12.0, H-2′), 6.92 (1H, d, J = 12.0, H-3′), 7.14 (2H, d, J = 8.0, H-9′, 5′), 8.13 (2H, d, J = 8.0, H-8′, 6′), 5.43 (1H, m, H-12), 5.20 (1H, m, H-3), 4.22 (1H, m, H-2) [3]. Jacoumaric Acid (2). C39H54O6, white amorphous powder. ESI-MS m/z 617 [M – H] –. 1H NMR (500 MHz, pyridine-d5, δ, ppm, J/Hz): 0.96 (3H, s, Me-23), 0.94 (3H, s, Me-24), 0.95 (3H, s, Me-25), 1.02 (3H, s, Me-26), 1.21 (3H, s, Me-27), 1.05 (3H, d, J = 6.5, Me-29), 1.03 (3H, d, J = 6.3, Me-30), 6.67 (1H, d, J = 16.0, H-2′), 7.99 (1H, d, J = 16.0, H-3′), 7.17 (2H, d, J = 8.5, H-9′, 5′), 7.55 (2H, d, J = 8.5, H-8′, 6′), 5.44 (1H, s, H-12), 5.25 (1H, m, H-3), 4.09 (1H, m, H-2) [3]. 3-O-trans-Feruloyl Euscaphic Acid (3). C40H56O8, white amorphous powder. ESI-MS m/z 663 [M – H] –. 1H NMR (400 MHz, pyridine-d5, δ, ppm, J/Hz): 0.92 (3H, s, Me-23), 0.78 (3H, s, Me-24), 0.93 (3H, s, Me-25), 0.86 (3H, s, Me-26), 1.27 (3H, s, Me-27), 1.19 (3H, s, Me-29), 0.98 (3H, d, J = 6.5, Me-30), 6.71 (1H, d, J = 15.8, H-2′), 8.00 (1H, d, J = 15.8, H-3′), 5.57 (1H, s, H-12), 5.25 (1H, m, H-3), 4.39 (1H, m, H-2) [4]. 2α,3α,19α,23-Tetrahydroxy-12-ursen-28-oic Acid (4). C30H48O6, white amorphous powder. ESI-MS m/z 503 [M – H]–. 1H NMR (600 MHz, pyridine-d5, δ, ppm, J/Hz): 1.05 (3H, s, Me-24), 0.88 (3H, s, Me-25), 1.11 (3H, s, Me-26), 1.68 (3H, s, Me-27), 1.40 (3H, s, Me-29), 1.13 (3H, d, J = 6.1, Me-30), 5.57 (1H, s, H-12), 4.32 (1H, m, H-2), 3.74 (1H, m, H-3), 3.07 (1H, m, H-18), 3.77 (1H, d, J = 10.8, H-23α), 3.94 (1H, d, J = 10.8, H-23β) [5].

Five new sucrose esters from the whole plants of Phyllanthus cochinchinensis

Abstract: Chemical investigation of the whole plants of Phyllanthus cochinchinensis (Euphorbiaceae) led to the isolation of five new sucrose benzoyl esters, 3,6′-di-O-benzoylsucrose (1), 3,6′-di-O-benzoyl-2′-O-acetylsucrose (2), 3,6′-di-O-benzoyl-4′-Oacetylsucrose (3), 3,6′-di-O-benzoyl-3′-O-acetylsucrose (4) and 3-O-benzoyl-6′-O-(E)-cinnamoylsucrose (5), together with two known secoiridoid glycosides, jasminoside (6) and jaslanceoside B (7). Their structures were established on the basis of detailed spectroscopic analysis and chemical method.

Catalytic Diastereoselective Pauson—Khand Reaction: An Efficient Route to Enantiopure Cyclopenta[c]proline Derivatives.

Abstract: Cyclopenta[c]proline derivatives were synthesized in a stereocontrolled manner and in good yields via catalytic Pauson−Khand reactions. The starting materials, optically pure enyne amino acid derivatives, can be easily prepared by an alkenylboronic acid-mediated Mannich-type reaction.

Application of arbutin sugar ester derivative in preparation of cosmetics or drugs

Abstract: The invention relates to an arbutin sugar ester derivative represented by a general formula I, a drug composition adopting the arbutin sugar ester derivative as an active component, and an application of the arbutin sugar ester derivative in preparation of skin whitening and spot removing cosmetics or drugs for skin whitening and pigmentation disease treatment. According to the present invention, with the arbutin sugar ester derivative, melanin can be effectively inhibited and decomposed so as to completely remove melanin spots and provide effects of whitening and spot removing; acute zebrafish toxicity test results show that the arbutin sugar ester derivative has characteristics of low toxicity, high activity, efficiency and safety compared with arbutin; and in the general formula I, R represents straight chain or branched chain saturated or unsaturated alkyl acyl, or trans or cis unsaturated aromatic acyl, R1 represents hydrogen atom, or straight chain or branched chain saturated or unsaturated alkyl acyl, or trans or cis unsaturated aromatic acyl, and R2 represents hydrogen atom, and/or hydroxy or methoxy or substituted acyl.

Screening of metal–organic frameworks for water adsorption heat transformation using structure–property relationships

Abstract: It is of great importance to correlate the water adsorption performance of MOFs to their physicochemical features in order to design and prepare MOFs for applications in adsorption heat transformation. In this work, both data analysis from existing studies and Grand Canonical Monte Carlo molecular simulation investigations were carried out. The results indicated that the highest water adsorption capacity was determined by the pore volume of MOF adsorbents, while there was a linear correlation interrelationship between isosteric heats of adsorption and the water adsorption performance at a low relative pressure. More detailed analysis showed that the charge distribution framework and pore size of MOFs contributed together to the hydrophilicity. Electrostatic interaction between water molecules and the framework atoms played a key role at low relative water pressure. A quantitative structure–property relationship model that can correlate the hydrophilicity of MOFs to their pore size and atomic partial charge was established. Along with some qualitative considerations, the screening methodology is proposed and is used to screen proper MOFs in the CoRE database. Seven MOFs were detected, and four of them were synthesized to validate the screening principle. The results indicated that these four MOFs possessed outstanding water adsorption performance and could be considered as promising candidates in applications for adsorption heating and cooling.

Different glacier status with atmospheric circulations in Tibetan Plateau and surroundings

Abstract: Glacial melting in the Tibetan Plateau affects the water resources of millions of people. This study finds that—partly owing to changes in atmospheric circulations and precipitation patterns—the most intensive glacier shrinkage is in the Himalayan region, whereas glacial retreat in the Pamir Plateau region is less apparent.