title: Nuclear magnetic resonance spectroscopy is highly sensitive for lipid-soluble metabolites.
abstract: Although the water-soluble metabolite profile of human mesenchymal stem cells is known, the lipid profile still needs further investigation. In this study, methanol-chloroform was used to extract pid-soluble metabolites and perchloric acid was used to extract water-soluble metabolites. Furthermore, a dual phase extraction method using methanol-chloroform and water was used to obtain both water and lipid fractions simultaneously. All metabolite extractions were analyzed on a 9.4T high-resolution nuclear magnetic resonance spectrometer. Metabolite resonance peaks were assigned in the acquired spectra according to the chemical shift, and the extraction efficiency of ferent methods was compared. Results showed that in the spectra of water-soluble extracts, major metabolites comprised low molecular weight metabolites, including lactate, acetic acid, fatty acids, threonine, glutamic acid, creatine, choline and its derivatives, while in the spectra of lipid-soluble extracts, most metabolites were assigned to fatty acids. Among the different extraction procedures, perchloric acid was more efficient in extracting water-soluble metabolites and methanol-chloroform was efficient in extracting organic components compared with the dual phase extraction method. Nuclear magnetic resonance spectroscopy showed that as low as 0.7 mg organic yield was enough to obtain clear resonance peaks, while about 6.0 mg water-soluble yield was needed to obtain relatively favorable spectral lines. These results show that the efficiency of extracting water and lipid fractions is higher using perchloric acid and methanol-chloroform compared with dual phase extraction and that nuclear magnetic resonance spectroscopy is highly sensitive for analyzing lipid-soluble extracts.
authors.affiliation: Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041; Department of Medical Imaging, Huizhou Municipal Central Hospital, Huizhou 516001, Guangdong Province, China ; Department of Radiology, the First People's Hospital of Foshan, Foshan 528000, Guangdong Province, China.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Dai
authors.affiliation: Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041; Department of Medical Imaging, Huizhou Municipal Central Hospital, Huizhou 516001, Guangdong Province, China.
authors.forename: Bikai
authors.initials: B
authors.lastname: Hong
authors.affiliation: Department of Pediatrics, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, Guangdong Province, China.
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Central Laboratory, Shantou University, Shantou 515041, Guangdong Province, China.
authors.forename: Lian
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, Guangdong Province, China.
authors.forename: Yaowen
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041; Department of Medical Imaging, Huizhou Municipal Central Hospital, Huizhou 516001, Guangdong Province, China.
authors.forename: Yeyu
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041; Department of Medical Imaging, Huizhou Municipal Central Hospital, Huizhou 516001, Guangdong Province, China.
authors.forename: Renhua
authors.initials: R
authors.lastname: Wu
keywords: extraction method; grants-supported paper; lipid-soluble; mesenchymal stem cells; metabolite profiles; methanol-chloroform; neural regeneration; neuroregeneration; nuclear magnetic resonance spectroscopy; optimization; perchloric acid; water-soluble