PMID- 19643074
OWN - NLM
STAT- MEDLINE
DCOM- 20091113
LR  - 20211020
IS  - 1096-0309 (Electronic)
IS  - 0003-2697 (Print)
IS  - 0003-2697 (Linking)
VI  - 394
IP  - 2
DP  - 2009 Nov 15
TI  - A gas chromatography-mass spectrometry method for the quantitation of 
      N-nitrosoproline and N-acetyl-S-allylcysteine in human urine: application to a 
      study of the effects of garlic consumption on nitrosation.
PG  - 243-8
LID - 10.1016/j.ab.2009.07.035 [doi]
AB  - Biomarkers in urine can provide useful information about the bioactivation of 
      chemical carcinogens and can be used to investigate the chemoprotective 
      properties of dietary nutrients. N-Nitrosoproline (NPRO) excretion has been used 
      as an index for endogenous nitrosation. In vitro and animal studies have reported 
      that compounds in garlic may suppress nitrosation and inhibit carcinogenesis. We 
      present a new method for extraction and sensitive detection of both NPRO and 
      N-acetyl-S-allylcysteine from urine. The latter is a metabolite of 
      S-allylcysteine, which is found in garlic. Urine was acidified and the organic 
      acids were extracted by reversed-phase extraction (RP-SPE) and use of a polymeric 
      weak anion exchange (WAX-SPE) resin. NPRO was quantified by isotope dilution gas 
      chromatography-mass spectrometry (GC-MS) using [13C5]NPRO and 
      N-nitrosopipecolinic acid (NPIC) as internal standards. This method was used to 
      analyze urine samples from a study that was designed to test whether garlic 
      supplementation inhibits NPRO synthesis. Using this method, 2.4 to 46.0 ng 
      NPRO/ml urine was detected. The method is straightforward and reliable, and it 
      can be performed with readily available GC-MS instruments. 
      N-Acetyl-S-allylcysteine was quantified in the same fraction and detectable at 
      levels of 4.1 to 176.4 ng/ml urine. The results suggest that 3 to 5 g of garlic 
      supplements inhibited NPRO synthesis to an extent similar to a 0.5-g dose of 
      ascorbic acid or a commercial supplement of aged garlic extract. Urinary NPRO 
      concentration was inversely associated with the N-acetyl-S-allylcysteine 
      concentration. It is possible that allyl sulfur compounds found in garlic may 
      inhibit nitrosation in humans.
FAU - Cope, Keary
AU  - Cope K
AD  - Phytonutrients Laboratory, USDA Human Nutrition Research Center, Beltsville, MD 
      20705, USA.
FAU - Seifried, Harold
AU  - Seifried H
FAU - Seifried, Rebecca
AU  - Seifried R
FAU - Milner, John
AU  - Milner J
FAU - Kris-Etherton, Penny
AU  - Kris-Etherton P
FAU - Harrison, Earl H
AU  - Harrison EH
LA  - eng
GR  - R01 DK044498/DK/NIDDK NIH HHS/United States
GR  - R01 DK044498-09/DK/NIDDK NIH HHS/United States
GR  - R01 HL049879/HL/NHLBI NIH HHS/United States
GR  - R01 HL049879-08/HL/NHLBI NIH HHS/United States
PT  - Journal Article
DEP - 20090728
PL  - United States
TA  - Anal Biochem
JT  - Analytical biochemistry
JID - 0370535
RN  - 0 (Carbon Isotopes)
RN  - 0 (Nitrosamines)
RN  - 23127-41-5 (N-acetyl-S-allylcysteine)
RN  - F8MI03SGY0 (nitrosoproline)
RN  - K848JZ4886 (Cysteine)
SB  - IM
MH  - Administration, Oral
MH  - Carbon Isotopes/metabolism
MH  - Cysteine/*analogs & derivatives/urine
MH  - *Garlic
MH  - Gas Chromatography-Mass Spectrometry/*methods
MH  - Humans
MH  - Linear Models
MH  - Nitrosamines/*urine
MH  - Nitrosation
MH  - Reference Standards
MH  - Specimen Handling
MH  - Statistics, Nonparametric
MH  - Time Factors
PMC - PMC2755231
MID - NIHMS136155
EDAT- 2009/08/01 09:00
MHDA- 2009/11/17 06:00
PMCR- 2010/11/15
CRDT- 2009/08/01 09:00
PHST- 2009/05/06 00:00 [received]
PHST- 2009/07/21 00:00 [revised]
PHST- 2009/07/22 00:00 [accepted]
PHST- 2009/08/01 09:00 [entrez]
PHST- 2009/08/01 09:00 [pubmed]
PHST- 2009/11/17 06:00 [medline]
PHST- 2010/11/15 00:00 [pmc-release]
AID - S0003-2697(09)00521-1 [pii]
AID - 10.1016/j.ab.2009.07.035 [doi]
PST - ppublish
SO  - Anal Biochem. 2009 Nov 15;394(2):243-8. doi: 10.1016/j.ab.2009.07.035. Epub 2009 
      Jul 28.