Erythrose revealed as furanose forms

Abstract

A non-conventional vaporization method, using laser ablation of solid NaCl doped with d-erythrose, has been used to bring this sugar into the gas phase for rotational study. The jet cooled rotational spectrum of this C4 monosaccharide reveals the existence of two furanose forms, one α envelope and one β twist. Cooperative hydrogen bond networks and the anomeric effect have been found to be the main stabilization factors of the detected structures.

Microwave Spectroscopy of Biomolecular Building Blocks

“…The low-temperature environment of a supersonic expansion provides the ideal medium for preparing individual conformers of sugars in virtual isolation conditions, ready to be interrogated by a short burst of microwave radiation. To date, rotational investigations of monosaccharides have been carried out for C 4 sugars [222], C 5 sugars [62,223,224], and C 6 sugars [225][226][227]. All factors contributing to stabilization of the observed species are given in the next sections.…”

“…The population ratio estimated from the relative intensity measurements cc-α-4 C 1 : c-α-4 C 1 % 1:0.03 is in good agreement with the theoretical predictions. The isotopic information corresponding to the five monosubstituted 13 C species of the most abundant conformer cc-α-4 C 1 was used to derive its structure [222]. Despite the sensitivity reached in the experiment, no traces belonging to β-pyranose forms have been detected.…”

“…Crystalline samples of D-xylose (m.p. ¼ 162 C) have been vaporized by laser ablation and probed by CP-FTMW [222] using a new parabolic reflector system [268]. The recorded broadband spectrum, shown in Fig.…”

“…Erythrose is a syrup at room temperature and is thermally decomposed using conventional heating methods, so it has been vaporized using laser ablation of solid NaCl doped with D-erythrose [222]. In the experimental procedure, some drops of D-erythrose were mixed with finely powdered NaCl and a small amount of a commercial binder.…”

Rotational spectrum of phenylglycinol

“…Moreover, the use of laser ablation helped studying molecules that would be otherwise unable to be vaporized using traditional heating methods. Nowadays, broadband microwave spectroscopic techniques (chirped pulsed Fourier transform microwave spectroscopy -CP-FTMW) [2], coupled with laser ablation, are being used to rapidly acquire the rotational spectra of solid compounds [2][3][4][5] in wide frequency ranges, making the search of different coexisting species in the supersonic jet more effective. On other hand, narrowband LA-MB-FTMW [6], provides the sub-Doppler resolution necessary to analyze the nuclear quadrupole coupling hyperfine structure of the observed species, which is a unique tool for the definitive ascription of the low-energy conformers [7][8][9].…”