Changwei Lv

Tanshinone IIA improves impaired nerve functions in experimental diabetic rats.

Diabetic neuropathy is one of the most common complications in diabetes mellitus. Thus far, effective therapeutic agents for restoring the impaired motor and sensory nerve functions in diabetic neuropathy are still lacking. The antioxidant and neuroprotective properties of tanshinone IIA make it a promising candidate for the treatment of diabetic neuropathy. Therefore, the present study investigated the possible beneficial effect of tanshinone IIA on the impaired nerve functions displayed by a rat diabetic model. Insulin-dependent diabetes in rats was developed by a single dose of streptozotocin (STZ) at 50mg/kg. The diabetic rats were randomly divided into four groups (n=10 in each group), and were intraperitoneally administrated daily for 4 weeks with tanshinone IIA (20mg/kg, 50mg/kg and 100mg/kg), or normal saline from the fourth day after STZ injection, respectively. At the end of tanshinone IIA administration, thermal and mechanical nociceptive threshold were determined by a hot plate test and Von Frey hairs; motor nerve conducting velocity (MNCV) was determined by an electrophysiological method; nerve blood flow (NBF) was detected using a laser Doppler flow meter; Na(+),K(+)ATPase activity, the level of superoxide dismutase (SOD), catalase and malondialdehyde (MDA) in sciatic nerves, and the serum total antioxidant capability were also determined. We found that tanshinone IIA was capable of restoring diabetes-induced deficit in nerve functions (MNCV and NBF), and impairment in thermal and mechanical nociceptive capability. In addition, tanshinone IIA significantly increased the serum total antioxidant capability, improved the activities of Na(+),K(+)ATPase, increased the levels of SOD and catalase, and reduced the MDA level in sciatic nerves in diabetic rats. All the findings indicate the beneficial effect of tanshinone IIA on impaired nerve functions and raise the possibility of developing tanshinone IIA as a therapeutic agent for diabetic neuropathy.

Pterostilbene exerts antitumor activity against human osteosarcoma cells by inhibiting the JAK2/STAT3 signaling pathway.

Osteosarcoma is a high-grade malignant bone tumor. Pterostilbene (PTE) is a natural, dimethylated analog of resveratrol with higher bioavailability. While PTE has been shown to have potent antitumor activity against various types of cancer, the molecular mechanisms underlying the effects of PTE remain largely unknown. The Janus kinase 2/Signal Transducer and Activator of Transcription 3 (JAK2/STAT3) signaling pathway plays a crucial role in tumorigenesis and immune development. In this study, we assessed the antitumor activity of PTE against human osteosarcoma cells and explored the role of JAK2/STAT3 and apoptosis-related signaling pathways on the activity of PTE. PTE treatment resulted in a dose- and time-dependent inhibition of osteosarcoma cell viability. Additionally, PTE exhibited strong antitumor activity, as evidenced not only by reductions in tumor cell adhesion, migration and mitochondrial membrane potential (MMP) but also by increases in the apoptotic index, reactive oxygen species (ROS) and several biochemical parameters. Furthermore, PTE treatment directly inhibited the phosphorylation of JAK2 at Tyr 1007 and the downstream activation of STAT3. PTE also down-regulated the expression of STAT3 target genes, including the anti-apoptotic proteins Bcl-xL and Mcl-1, leading to the up-regulation of mitochondrial apoptosis pathway-related proteins (Bax, Bak, cytosolic Cytochrome c, and cleaved Caspase3) and cyclin-dependent kinase inhibitors such as p21 and p27. PTE, used in combination with a known JAK2/STAT3 inhibitor, AG490, further decreased the viability of osteosarcoma cells. Taken together, PTE is a potent inhibitor of osteosarcoma cell growth that targets the JAK2/STAT3 signaling pathway. These data suggest that inhibition of JAK2/STAT3 signaling is a novel mechanism of action for PTE during therapeutic intervention in osteosarcoma cancers.

Synthesis of Biscoumarin and Dihydropyran Derivatives and Evaluation of Their Antibacterial Activity

In an attempt to find a new class antibacterial agents, a series of biscoumarins (1–4) and dihydropyrans (5–13) were successfully prepared. The molecular structures of four representative compounds, that is, 4, 5, 8 and 12 were confirmed by single crystal X-ray diffraction study. These synthesized compounds were screened for their antibacterial activity in vitro against Staphylococcus aureus (S. aureus ATCC 29213), methicillin-resistant S. aureus (MRSA XJ 75302), vancomycin-intermediate S. aureus (Mu50 ATCC 700699), USA 300 (Los Angeles County clone, LAC), Staphylococcus epidermidis (S. epidermidis ATCC 14990), methicillin-resistant S. epidermidis (MRSE XJ 75284) and Escherichia coli (E. coli ATCC 25922). Additionally, there are two classical intramolecular O–H···O hydrogen bonds (HBs) in biscoumarins 1–4 and the corresponding HB energies were further performed with the density functional theory (DFT) [B3LYP/6-31G*] method.

Synthesis, photoluminescent, antibacterial activities and theoretical studies of three novel coumarin and dihydropyran derivatives containing a triphenylamine group

Three new coumarin and dihydropyran derivatives (1–3) have been synthesized and their fluorescence behaviors in dichloromethane solutions were observed. The molecular structures of two representative compounds, 2 and 3, were confirmed by single crystal X-ray diffraction study. The three synthesized compounds were evaluated for their antibacterial activities against Staphylococcus aureus (S. aureus ATCC 29213), methicillin-resistant S. aureus (MRSA XJ 75302), vancomycin-intermediate S. aureus (Mu50 ATCC 700699), and USA 300 (Los Angeles County clone) in vitro by observing the minimum inhibitory concentration.

Evaluation of Antibacterial Activities of 4-Hydroxycoumarin Derivatives

Abstract Three kinds of 4-hydroxycoumarin derivatives, namely, biscoumarins (1–4), epoxydicoumarins (5–8) and dihydropyrans (9–12), were synthesized and the antibacterial activity of each of them was evaluated. The result of preliminary bioassay shows that the lowest minimal inhibitory concentration (MIC) of compounds 1 and 2 against drug-sensitive S. aureus (ATCC 29213) and methicillin-resistant S. aureus (MRSA XJ 75302, Mu50, ATCC 700699 and USA 300) is 4–64 ug/mL. Additionally, there are two classical intramolecular O—H⋯O hydrogen bonds (HBs) in the structures of biscoumarins (1–4), and their corresponding HB energies were further calculated by the density functional theory (DFT) [B3LYP/6-31G*] method.

Simultaneous Presence of Two Conformers of the Same Macrocyclic Compound in the Crystal: Synthesis and Crystal Structures of a New Macrocyclic Compound

A new macrocyclic compound, [Ni(L)](ClO4)2 (1) (L = 1,3,10,12,15,18-hexaazatetracyclo [16,2,1,112.15,04.9]docosane) was synthesized by condensation reactions involving amines and formaldehyde in the present of nickel anion. Compound 1 crystallizes in monoclinic, space group Cc, with a = 13.802(11) Å, b = 12.975(10) Å, c = 13.322(11) Å, α = 90°, β = 99.439(9)°, γ = 90°, V = 2353(3) Å3, Z = 4, F(000) = 1184, D c = 1.598 Mg/m3, M r = 566.09, μ = 1.106 mm−1, λ = 0.71073 Å, the final R = 0.0425 and ωR = 0.1235 for 2,030 observed reflections with I > 2σ(I). X-ray crystallographic analysis shows simultaneous presence of two conformers of the same macrocyclic compound [Ni(L)]2+ in the crystal.

Synthesis, Crystal Structure, and Properties of a New Binuclear Copper(II) Compound Based on Macrocyclic Precursor [Cu(L)(H2O)][Cu(L)(N3)](ClO4)3·2H2O (L = 1,3,10,12,15,18-hexaazatetracyclodocosane)

A new binuclear copper (II) compound [Cu(L)(H2O)] [Cu(L)(N3)]·(ClO4)3·2H2O (L = 1,3,10,12,15,18-hexaazatetracyclo [16,2,1,112.15,04.9]docosane) has been synthesized and characterized. Purple crystals crystallize in triclinic, space group P–1 with a = 10.180(2) Å, b = 15.393(3) Å, c = 16.299(3) Å, α = 100.211(3)º, β = 104.576(3)º, γ = 92.102(3)º, V = 2423.8(8) Å3, Z = 2, F(000) = 1182, D c = 1.553 Mg/m3, M r = 1133.42, μ = 1.121 mm−1, λ = 0.71073 Å, the final R = 0.0662 and ωR = 0.1747 for 9346 observed reflections with I > 2σ(I).