Helicoselective Synthesis of Indolohelicenoids through Organocatalytic Central-to-Helical Chirality Conversion.

We report the helicoselective and convergent construction of indolohelicenoids with excellent efficiency and stereocontrol. This reaction proceeds through a chiral-phosphoric-acid-catalyzed enantioselective cycloaddition and eliminative aromatization sequence, which can be finely controlled by adjusting the reaction temperature. Mechanistic studies reveal that the chiral phosphoric acid cooperatively serves as both a bifunctional and Brønsted acid catalyst, enabling one-pot central-to-helical chirality conversion. Additionally, the optical properties of the synthesized indolohelicenoids were characterized to explore their potential applications in organic photoelectric materials.

Organocatalytic cycloaddition-elimination cascade for atroposelective construction of heterobiaryls.

The first chiral phosphoric acid (CPA) catalyzed cycloaddition-elimination cascade reaction of 2-naphthol- and phenol-derived enecarbamates with azonaphthalenes has been established, providing a highly atroposelective route to an array of axially chiral aryl-C3-benzoindoles in excellent yields with excellent enantioselectivities. The success of this strategy derives from the stepwise process involving CPA-catalyzed asymmetric formal [3 + 2] cycloaddition and subsequent central-to-axial chirality conversion by elimination of a carbamate. In addition, the practicality of this reaction had been verified by varieties of transformations towards functionalized atropisomers.

A Dy4 single-molecule magnet and its Gd(iii), Tb(iii), Ho(iii), and Er(iii) analogues encapsulated by an 8-hydroxyquinoline Schiff base derivative and ß-diketonate coligand.

Five new tetranuclear complexes based on an 8-hydroxyquinoline Schiff base derivative and the ß-diketone coligand, [Ln4(acac)4L6(µ3-OH)2]·CH3CN·0.5CH2Cl2 (Ln = Gd (1), Tb (2), Dy (3), Ho (4) and Er (5); HL = 5-(benzylidene)amino-8-hydroxyquinoline; acac = acetylacetonate) have been synthesized, and structurally and magnetically characterized. Complexes 1-5 have similar tetranuclear structures. Each LnIII ion is eight coordinated and its coordination polyhedra can be described as being in a distorted square-antiprismatic geometry. The magnetic studies reveal that 1 features the magnetocaloric effect (MCE) with the magnetic entropy change of -ΔSm(T) = 25.08 J kg-1 K-1 at 2 K for ΔH = 7 T, and 3 displays the slow magnetic relaxation behavior of Single Molecule Magnets (SMMs) with the anisotropic barrier of 86.20 K and the pre-exponential factor τ0 = 2.99 × 10-8 s.

Modulation of the relaxation dynamics of linear-shaped tetranuclear rare-earth clusters through utilizing different solvents.

Nine new tetranuclear centrosymmetric linear complexes, [RE4(dbm)8L2(DMF)2]·nCH2Cl2·mC2H3N (RE = Y (1), Tb (2), Dy (3), Ho (4), Er (5), Lu (6)) and [RE4(dbm)8L2(C2H5OH)2]·nCH3CN (RE = Tb (7), Dy (8), Ho (9)) (HL = 2-[(2-(hydroxyimino)propanehydrazide)methyl]-8-hydroxyquinoline and dbm = 1,3-diphenyl-1,3-propanedione) have been synthesized. Complexes 1-9 are tetranuclear complexes. Magnetic studies reveal that both DyIII-based complexes (3 and 8) exhibit single-molecule magnet (SMM) behavior under a zero dc field. Furthermore, complex 3 presents one relaxation process under a zero dc field, while application of an external dc field (1500 Oe) induces multi-relaxation signals of the ac magnetic susceptibility.

[Comparison of the efficacy of second line EGFR TKIs followed by third line pemetrexed or the reverse sequence in the treatment of advanced lung adenocarcinoma].

OBJECTIVE: To compare the efficacy of second-line EGFR-TKIs followed by third-line pemetrexed with second-line pemetrexed followed by third-line EGFR-TKIs in patients with advanced lung adenocarcinoma. METHODS: From March 2007 to August 2008, 83 patients with advanced lung adenocarcinoma who failed standard first-line chemotherapy were included in this study. The patients who received EGFR-TKIs as second-line therapy followed by third-line pemetrexed were designated as group A (n = 45). The patients who received pemetrexed as second-line therapy followed by third-line EGFR-TKIs were designated as group B (n = 38). PFS and MST were estimated with Kaplan-Meier analysis and the difference between groups were compared with Log-rank test. RESULTS: The progression-free survival (PFS) after second-line therapy in the groups A and B was 8.05 months (95% CI, 5.90 to 10.20) and 4.20 months (95% CI, 3.33 to 5.06), respectively (P = 0.001). The PFS after second-line therapy in smokers and non-smokers was 3.69 months (95% CI, 5.00 to 7.59) and 7.12 months (95% CI, 5.51 to 8.38), respectively (P = 0.007). The PFS of male and female patients was 5.56 months (95% CI, 4.02 to 7.10) and 6.85 months (95% CI, 4.98 to 7.58), respectively (P = 0.279). The PFS after third-line therapy in groups A and B was 6.88 months (95% CI, 5.07 to 8.69) and 7.60 months (95% CI, 5.59 to 9.12) respectively, (P = 0.899). The PFS after third-line therapy in smokers and non-smokers was 4.95 months (95% CI, 2.83 to 7.05) and 8.49 months (95% CI, 6.27 to 10.76), respectively (P = 0.050). The PFS after third-line therapy in male and female patients was 5. 96 months (95% CI, 4.02 to 7.91) amd 8.38 months (95% CI, 5.68 to 11.07), respectively (P = 0.176). The MST in groups A and B was 23.60 months (95% CI, 19.23 to 28.00) and 15.58 months (95% CI, 11.85 to 19.32), respectively (P = 0.021). The MST in smokers and non-smokers was 11.99 months (95% CI, 8.55 to 15.49) and 23.18 months (95% CI, 19.33 to 27.02), respectively (P = 0.001). The MST in male and female patients was 17.40 months (95% CI, 13. 19 to 21.61) and 22.74 months (95% CI, 18.29 to 27.19), respectively (P = 0.111). CONCLUSIONS: Second line EGFR TKIs followed by third line pemetrexed regimen improves the PFS and MST compared with the regimen second line pemetrexed followed by third line EGFR TKIs in patients with advanced lung adenocarcinoma. Smoking status is an independent prognostic factor. Survival is not influenced by gender. Prospective clinical trials are needed to confirm these findings.

[Efficacy and safety of docetaxol, pemetrexed and EGFR-TKIs as second-line treatment for patients with advanced non-small-cell lung cancer].

OBJECTIVE: To compare the efficacy and safety of docetaxol, pemetrexed and EGFR-TKIs in the second-line treatment for patients with advanced non-small cell lung cancer. METHODS: The clinical data of 170 patients with advanced non-small cell lung cancer who failed standard first-line chemotherapy were reviewed. Those who received docetaxol as second-line therapy were designated as group A (n = 60), those who received pemetrexed as second-line therapy were designated as group B (n = 49), and those who received EGFR-TKIs as second-line therapy were designated as group C (n = 61). PFS and MST were estimated by Kaplan-Meier method and the differences between groups were compared by log-rank test. RESULTS: The response rate in the groups A, B and C group was 15.0% (9/60), 24.5% (12/49) and 36.1% (22/61), respectively. The PFS after second-line therapy in the groups A, B and C was 5.49 months (95%CI: 4.03 - 6.95 months), 5.42 months (95%CI: 4.23 - 6.60 months) and 9.31 months (95%CI: 6.88 - 11.73 months), respectively (P = 0.045). The MST after second-line therapy in the groups A, B and C was 14.89 months (95%CI: 11.23 - 18.55 months), 15.81 months (95%CI: 12.11 - 19.52 months) and 17.47 months (95%CI: 13.38 - 21.56 months), respectively (P = 0.574). Regression analysis showed that the performance status score (PS) and response for second-line treatment are independent prognostic factors in each sub-group, and pathological type is an independent prognostic factor in the group C (P = 0.003). CONCLUSIONS: The safety of the three drugs used as second-line treatment for patients with advanced non-small-cell lung cancer, who failed standard first-line chemotherapy, is comparable, but the EGFR-TKIs group has the highest response rate, and the EGFR-TKIs group has the longest PFS with a statistically significant difference, while there is no significant difference in MST among the three groups. When patients receive second-line treatment, the performance status < 2 and the response rate for second-line treatment are independent prognostic factors. Furthermore, pathological type (adenocarcinoma) is also an independent prognostic factor for EGFR-TKIs as second-line treatment.

Polymorphism of vascular endothelial growth factor -1154G>A (rs1570360) with cancer risk: a meta-analysis of 16 case-control studies.

Published data on the association of vascular endothelial growth factor (VEGF) -1154G>A polymorphism with cancer risk is inconclusive. To derive a more precise estimation of association between VEGF -1154G>A polymorphism and the risk of cancer, we performed a meta-analysis of 7,071 cancer cases and 7,693 controls from 16 published case-control studies. Our meta-analysis didn't reveal an association between VEGF -1154G>A polymorphism and overall cancer risk (GG vs. AA: OR: 1.08, 95% CI: 0.96-1.20; GA vs. AA: OR: 1.04, 95% CI: 0.93-1.17; recessive model: GG+GA vs. AA: OR: 1.06, 95% CI: 0.95-1.18; dominant model: GG vs. GA+AA, OR: 1.11, 95% CI: 1.00-1.24). Nevertheless, for non-Caucasians, GG homozygote may have higher cancer risk compared with either A carriers (OR: 1.58, 95% CI: 1.12-2.23) or AA homozygote (OR: 1.43, 95% CI: 1.17-1.76). No significant heterogeneity was detected except in the dominant model and "prostate cancer" subgroup analysis. More studies with larger samples are warranted to confirm these findings.