Ming-Jin Xie

Insulin-enhancing activity of a dinuclear vanadium complex: 5-chloro-salicylaldhyde ethylenediamine oxovanadium(V) and its permeability and cytotoxicity

A new insulin-enhancing oxovanadium complex 5-chloro-salicylaldhyde ethylenediamine oxovanadium (V) ([V(2)O(2)(mu-O)(2)L(2)]) has been synthesized. The complex was characterized by a variety of physical methods, including X-ray crystallography. The X-ray diffraction analysis show a dinuclear complex of two six-coordinate vanadium centers doubly bridged by the oxygen atoms of the Schiff base ligand with a V(2)O(2) diamond core. The complex was administered intragastrically to STZ-diabetic rats for 2 weeks. The biological activity results show that the complex at the dose of 10.0 and 20.0 mg V kg(-1), could significantly decrease the blood glucose level and ameliorate impaired glucose tolerance in STZ-diabetic rats. That results suggested that the complex exerts an antidiabetic effect in STZ-diabetic rats. Furthermore, the complex ([V(2)O(2)(mu-O)(2)L(2)]) had permeability above 10(-5)cm/s. The experimental results suggested that the vanadium complex permeates via a passive diffusion mechanism. It was also suggested the complex with salen-type ligands has good lipophilic properties and better oral administration. The cytotoxicity of the complex ([V(2)O(2)(mu-O)(2)L(2)]) on Caco-2 cells was measured by a decrease of cell viability using the MTT assay suggesting that the chlorine atom at C4 of complex [V(2)O(2)(mu-O)(2)L(2)] increased cytotoxicity for vanadium complexes.

Defensive Sesterterpenoids with Unusual Antipodal Cyclopentenones from the Leaves of Leucosceptrum canum

Two novel sesterterpenoids, leucosceptroids C (1) and D (2), possessing unusual antipodal cyclopentenones while maintaining the stereochemistry and functionality of the tricyclic cores, were discovered from the leaves of Leucosceptrum canum (Labiatae). Their structures including absolute stereochemistries were determined by comprehensive NMR, MS, and single-crystal X-ray diffraction analyses. The potent antifeedant activity of 1 against the generalist plant-feeding insect Helicoverpa armigera (EC(50) = 0.017 μmol/cm(2)) suggested them to be new defensive sesterterpenoids of L. canum.

Novel polyesterified 3,4-seco-grayanane diterpenoids as antifeedants from Pieris formosa.

Pieris formosa is a poisonous plant to livestock and is used as an insecticide in rural areas of China. Two novel polyesterified 3,4-seco-grayanane diterpenoids, pierisoids A and B (1 and 2), were isolated from its flowers and were identified by spectroscopic analysis and X-ray diffraction. Both compounds showed obvious antifeedant activity against cotton bollworm, indicating their toxic properties, suggesting a defensive role of polyesterified 3,4-seco-grayanane diterpenoids for P. formosa against herbivores.

Synthesis and anticancer activity of [2-hydroxy-1,3-diaminopropane-κ2N,N'] platinum(II) complexes

A series of novel platinum(II) complexes involving a carrier with HO- peripheral functional group, 2-hydroxy-1,3-propanediamine (HO-pda), cis-[Pt(HO-dpa)X(2)] (X(2)=2Cl(-) (1), C(2)O(4)(2-) (2), malonate (3), 1,1-cyclobutane dicarboxylate (CBDCA) (4), 3-hydroxy-1,1-cyclobutanedicarboxylate (HO-CBDCA) (5)), have been synthesized and characterized by elemental analysis and spectroscopic data along with X-ray diffraction for three representative complexes 1, 4 and 5. The Pt(II) is in a square planar environment and is coordinated in cis position by a chelating HO-pda and 2Cl(-) for 1 and CBDCA for 4 and 5. Pt-N, Pt-Cl and Pt-O distances and coordinate bond angles of N-Pt-N, Cl-Pt-Cl and O-Pt-O are in the normal range. There are two independent molecules in the asymmetric unit of 5, held together by intermolecular hydrogen bonded chain. All the complexes show significant cytotoxicity on the sensitive cell lines SGC-7901, LNcap and A549, and are more active than carboplatin. 4 is also found to be active against the resistant cell A549/ATCC, which suggests that it has less cross-resistance with cisplatin than carboplatin. Moreover 4 shows much greater inhibition of tumor growth than carboplatin in S180-bearing mice, and is therefore worthy of further development as a potential anti-tumor platinum drug.

A novel water-soluble heptaplatin analogue with improved antitumor activity and reduced toxicity.

A novel water-soluble heptaplatin analogue, cis-[(4R,5R)-4,5-bis-(aminomethyl)-2-isopropyl-1,3-dioxolane](3-hydroxy-1,1-cyclobutanedicarboxylato)platinum(II), has been synthesized and biologically evaluated. The complex shows more activity and less toxicity than its parent drug heptaplatin, exhibiting the great potential for further development.

Unusual Dimeric Chemical Structure for a Carboplatin Analogue as a Potential Anticancer Complex

An unexpected and unusual dimeric platinum(II) tetracarboxylate complex was obtained by the reaction of cis-[Pt(NH(3))(2)I(2)] with disilver dicarboxylate. The complex exhibits greater in vitro anticancer activity and lower toxicity in mice than its parent compound, carboplatin, and is therefore worthy of further evaluation as a potential antitumor dinuclear platinum agent.

A chiral porous cobalt–organic framework based on reinforced sinusoidal-like SBUs involving in situ-generated formate

The assembly of Co(NO3)2·6H2O and achiral isonicotinic acid (HIN) under solvo(hydro)thermal conditions yields a three-dimensional chiral Co-based MOF, {[Co6(μ3-OH)2(IN)4(HCOO)6]·4DMF·5H2O}n (1). Polymer 1 consists of a reinforced sinusoidal-like hydroxyl–formate–carboxylate mixed-bridged chain as a rod-shaped secondary building unit (SBU), which is constructed from two types of asymmetric triangular Co3 clusters. This compound also has open irregular channels in the framework and presents a severely distorted pcu net based on two different Co3 clusters of SBUs as six connected nodes. The presence of a few drops of water in the DMF reaction solution is important in in situ HCOO− generation, which is beneficial for the formation of 1. Compound 1 is further characterized by IR, EA, PXRD, TGA-DSC, N2 adsorption, and magnetic measurement.

Bis(α-furancarboxylato)oxovanadium(IV) prevents and improves dexamethasone-induced insulin resistance in 3T3-L1 adipocytes

Previous studies showed that bis(α‐furancarboxylato)oxovanadium(IV) (BFOV), an orally active antidiabetic organic vanadium complex, could improve insulin resistance in animals with type 2 diabetes. The present study has been carried out to evaluate the effects of BFOV on insulin‐resistant glucose metabolism using dexamethasone‐treated 3T3‐L1 adipocytes as an in‐vitro model of insulin resistance. The results showed that BFOV, similar to vanadyl sulfate and rosiglitazone, caused a concentration‐dependent increase in glucose consumption by insulin‐resistant adipocytes. Moreover, BFOV enhanced the action of insulin and completely prevented the development of insulin resistance induced by dexamethasone, leading to glucose consumption equal to that by normal cells. In addition, dexamethasone reduced the mRNA expression of insulin receptor substrate 1 (IRS‐1) and glucose transporter 4 (GLUT4) in 3T3‐L1 adipocytes, while BFOV normalized the expression of IRS‐1 and GLUT4. These findings suggest that BFOV prevents and improves dexamethasone‐induced insulin resistance in 3T3‐L1 adipocytes by enhancing expression of IRS‐1 and GLUT4 mRNA.

Synthesis and cytotoxicity of platinum(II) complexes of a physiologically active carrier histamine.

A series of novel platinum(II) complexes involving a physiologically active carrier histamine as the carrier, cis‐[Pt(histamine)X2] (X2 = 2Cl–, oxalate, malonate, 1,1‐cyclobutanedicarboxylate (CBDCA), 3‐hydroxy‐1,1‐cyclobutanedicarboxylate (HO‐CBDCA)), have been synthesized and characterized by elemental analysis and spectroscopic data along with X‐ray crystal structure for a representative complex cis‐[Pt(histamine)Cl2]. The cytotoxicity of the complexes has also been assessed in the human cancer cell lines A549/ATCC, HT‐29, and LNcap. One complex, cis‐[Pt(histamine)Cl2], is more active than carboplatin against both the sensitive and resistant cells.

cis-[PtII(1R,2R-DACH)(3-acetoxy-1,1-cyclobutanedicarboxylato)], a Water-Soluble, Oxalate-Free and Stable Analogue of Oxaliplatin: Synthesis, Characterization, and Biological Evaluations

Oxaliplatin, developed by Kidani et al. , is a third-generation platinum antitumor drug following cisplatin and carboplatin, and has been used worldwide in combination chemotherapeutic treatments of metastatic colorectal cancer. Oxaliplatin is also currently being explored for its potential as a treatment option after failure of cisplatin or carboplatin therapy, owing to its activity in cisplatin-resistant tumor models. Oxaliplatin differs from carboplatin importantly in that two ammine groups of the latter are replaced by (1R,2R)-diaminocyclohexane (DACH), which is largely credited for the unique anticancer properties of oxaliplatin. However, the efficacy of oxaliplatin is