Design, Synthesis and Biological Evaluation of Pentacyclic Triterpene Derivatives: Optimization of Anti-ABL Kinase Activity

Imatinib, an Abelson (ABL) tyrosine kinase inhibitor, is a lead molecular-targeted drug against chronic myelogenous leukemia (CML). To overcome its resistance and adverse effects, new inhibitors of ABL kinase are needed. Our previous study showed that the benzyl ester of gypsogenin (1c), a pentacyclic triterpene, has anti-ABL kinase and a subsequent anti-CML activity. To optimize its activities, benzyl esters of carefully selected triterpenes (PT1-PT6), from different classes comprising oleanane, ursane and lupane, and new substituted benzyl esters of gypsogenin (GP1-GP5) were synthesized. All of the synthesized compounds were purified and charachterized by different spectroscopic methods. Cytotoxicity of the parent triterpenes and the synthesized compounds against CML cell line K562 was examined; revealing three promising compounds PT5, GP2 and GP5 (IC50 5.46, 4.78 and 3.19 μM, respectively). These compounds were shown to inhibit extracellular signal-regulated kinase (ERK) downstream signaling, and induce apoptosis in K562 cells. Among them, PT5 was identified to have in vitro activity (IC50 = 1.44 μM) against ABL1 kinase, about sixfold of 1c, which was justified by molecular docking. The in vitro activities of GP2 and GP5 are less than PT5, hence they were supposed to possess other more mechanisms of cytotoxicity. In general, our design and derivatizations resulted in enhancing the activity against ABL1 kinase and CML cells.

Weight gain and recurrence in idiopathic intracranial hypertension: a case-control study

OBJECTIVE

To determine whether weight gain is associated with recurrence in idiopathic intracranial hypertension (IIH).

METHODS

Medical records of adult patients with IIH seen between 1993 and 2009 at 2 university hospitals were reviewed to identify those with and without recurrence. Patients with documented height and weight at presentation and at subsequent visits were studied. The Wilcoxon rank sum test was used to compare mean body mass index (BMI) and percent weight change between the groups of patients with recurrence and without recurrence. The signed-rank test was used for comparing BMI within groups at the various time points.

RESULTS

Fifty women with IIH were included in the analyses: 26 had IIH recurrence and 24 did not. Patients with recurrence had greater BMI at the time of recurrence compared to BMI at diagnosis (p = 0.02, signed-rank test). They also demonstrated a greater degree of weight gain between initial resolution and recurrence (BMI change +2.0 kg/m(2) [-1.5 to 10.8]) compared to patients without recurrence (-0.75 kg/m(2) [-35 to 3.6], p = 0.0009, Wilcoxon rank sum test). Patients without recurrence demonstrated stable weights (0%[95% CI -9.6 to 10.1%]), while patients with recurrence demonstrated a 6% weight gain ([-3.5 to 40.2%], p = 0.005), with an average rate of BMI gain of 1.3 kg/m(2)/year vs -0.96 kg/m(2)/year in those without recurrence.

CONCLUSION

Patients with IIH recurrence had significant increases in BMI compared to patients without recurrence in this cohort. Patients with resolved IIH should be advised that weight gain may be a risk factor for IIH recurrence.