Configurational and conformational analysis of chiral molecules using IR and VCD spectroscopies: spiropentylcarboxylic acid methyl ester and spiropentyl acetate.

The chiral monosubstituted derivatives of spiropentane, spiropentylcarboxylic acid methyl ester, 1, and spiropentyl acetate, 2, have been synthesized in optically active form. Configurational and conformational analysis of 1 and 2 has been carried out using infrared (IR) and vibrational circular dichroism (VCD) spectroscopies. Analysis of the experimental IR and VCD spectra has been carried out using ab initio density functional theory (DFT). For both 1 and 2, DFT predicts two populated conformations. Comparison to experiment of the conformationally averaged IR and VCD spectra of 1 and 2, predicted using DFT, provides unequivocal evidence of the predicted conformations and yields the absolute configurations R(-)/S(+) for 1 and R(+)/S(-) for 2. These absolute configurations are consistent with the R(-)/S(+) absolute configuration of spiropentylcarboxylic acid, assigned previously via X-ray crystallography of its alpha-phenylethylammonium salt.

Reduction of inflammation following cataract surgery by the nonsteroidal anti-inflammatory drug, flurbiprofen.

In this double-masked clinical trial, 72 patients undergoing cataract extraction surgery received a topical loading dose of 0.03% flurbiprofen or vehicle before surgery and one drop four times daily for 2 weeks after surgery. The severity of conjunctival hyperemia, aqueous humor cells, and aqueous humor flare was lower in the flurbiprofen-treated group than in the vehicle-treated group at all follow-up visits; the differences were significant on day 14. Four patients treated with flurbiprofen and two treated with vehicle exhibited postoperative hyphemas. Treatment with flurbiprofen appeared to decrease the severity of inflammation following cataract extraction surgery.