Maturation, capacitation, and metabolism of goat spermatozoa using magnetic resonance methods

Identification of low-molecular-weight compounds in goat epididymis using multinuclear nuclear magnetic resonance

Multinuclear nuclear magnetic resonance (NMR) (1H, 13C, and 31P) studies have been performed on aqueous solutions of lyophilysates of cell-free extract, epididymal fluid, and intact cells from caput and cauda regions of epididymis of sacrificed goats. Identification of low-molecular-weight compounds present in different maturation phases of spermatozoa has been carried out. Several low-molecular-weight compounds have been identified by assigning 600 MHz 1H NMR spectra with the help of two-dimensional homonuclear and heteronuclear correlation spectroscopy such as double quantum filtered correlation spectroscopy and heteronuclear single quantum correlation spectroscopy. Homonuclear coupling constants have also been used to get unambiguous assignments of resonances. NMR data were compared with those of standard samples measured at same pH and with those reported in the literature. Identification of several amino acids, carbohydrates, and lipids have been made and their presence has been discussed in relation to their relevance to sperm functions. The presence of beta-alanine and hypotaurine has been reported for the first time in goat epididymis.