FT-IR, FT-Raman spectra, density functional computations of the vibrational spectra and molecular conformational analysis of 2,5-di-tert-butyl-hydroquinone

The purpose of finding conformer among six different possible conformers of 2,5-di-tert-butyl-hydroquinone (DTBHQ), its equilibrium geometry and harmonic wavenumbers were calculated by the B3LYP/6-31G(d,p) method. The infrared and Raman spectra of DTBHQ were recorded in the region 400-4000 cm(-1) and 50-3500 cm(-1), respectively. In addition, the IR spectra in CCl(4) at various concentrations of DTBHQ are also recorded. The computed vibrational wavenumbers were compared with the IR and Raman experimental data. Computational calculations at B3LYP level with two different basis sets 6-31G(d,p) and 6-311++G(d,p) are also employed in the study of the possible conformer of DTBHQ. The complete assignments were performed on the basis of the potential energy distribution (PED) of the vibrational modes, calculated using VEDA 4 program. The general agreement between the observed and calculated frequencies was established.

FT-IR, FT-Raman spectra, density functional computations of the vibrational spectra and molecular geometry of butylated hydroxy toluene

The FT-IR spectrum of 2,6-di-tert-butyl-4-methylphenol [butylated hydroxy toluene] was recorded in the region 4000-400 cm(-1). The FT-Raman spectrum of butylated hydroxy toluene was also recorded in the region 3500-50 cm(-1). The molecular structure and vibrational frequencies of butylated hydroxy toluene (BHT) have been investigated with combined experimental and theoretical study. Two stable conformers of the title compound were obtained from the result of geometry optimizations of these possible conformers. The conformer 1 is (approximately 2.6 kcal/mol) more stable than conformer 2. Geometry optimizations and vibrational frequency calculations were performed by BLYP and B3LYP methods using 6-31G(d), 6-31G(d,p) and 6-31+G(d,p) as basis sets. The scaled frequencies were compared with experimental spectrum and on the basis of this comparison; assignments of fundamental vibrational modes were examined. Comparison of the experimental spectra with harmonic vibrational wavenumbers indicates that B3LYP/6-31G(d) results are more accurate. Predicted electronic absorption spectra of BHT from TD-DFT calculation have been analyzed and compared with the experimental UV-vis spectrum. The calculated HOMO and LUMO energies show that the charge transfer occurs within the molecule.

Partial intestinal obstruction due to childhood refractory hon-Hodgkin's lymphoma, successfully treated with taxol

In this report, we present a six-year-old male patient with partial intestinal obstruction due to refractory Non-Hodgkin's lymphoma (NHL) whose partial obstruction was successfully treated with Taxol(R) without any surgical intervention. Following an unsuccessful treatment attempt to treat his high-grade (stage 3) B-cell lymphoma with standard and second-line chemotherapy regimens he was started on radiotherapy and third line chemotherapy during which he was admitted with partial obstructive ileus as a result of tumor progression. Treatment was continued with Taxol(R) and resulted in total cure of the ileus with reduction of palpable tumor mass over 24 h without necessitating any surgery. Taxol(R) (200 mg/m (2)/week) was administered without any major side effects/toxicities for six courses. A control CT of the abdomen revealed a significant reduction in tumor size. After the next course, the patient developed severe thrombocytopenia that unfortunately did not resolve before the patient died as a result of further tumor growth and dissemination. Although there are studies that report response to Taxol(R) treatment in adult patients with refractory NHL, our review of the literature failed to demonstrate any report about the effectiveness of Taxol(R) in childhood NHL. In conclusion, our case may indicate that Taxol(R) can be effective and be administered safely in an outpatient setting in children with refractory NHL with the aim of prolonging the survival without sacrificing good quality of life. Studies on larger number of patients are needed to make a definitive conclusion about the value of Taxol(R) in refractory childhood NHL.