Tobacco-specific nitrosamine accumulation and distribution in flue-cured tobacco alkaloid isolines

Djordjevic, Mirjana V.; Bush, Lowell P.; Chaplin, J. F.

doi:10.1021/jf00087a040

Cited by 35 publications

(33 citation statements)

References 13 publications

(17 reference statements)

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“…In addition, the alkaloid content in the upper leaves was evidently higher than those of the middle and lower leaves of N. tabacum (Table 2). Similar results have been reported previously (Djordjevic et al, 1989;Shi et al, 2001;Lin et al, 2002). Djordjevic et al (1989) found that in NC95, the contents of nicotine, nornicotine, and anatabine from upper stalk positions exceeded those from lower and middle stalk positions.…”

Section: Alkaloid Contentsupporting

confidence: 93%

“…However, each step in the processing of tobacco leaves that affects plant metabolism may result in changes in the alkaloid content to a certain degree (Djordjevic and Doran, 2009). Djordjevic et al (1989) found that the contents of nicotine, nornicotine, anatabine, and anabasine increased in NC95 from harvesting through curing. By using fresh leaves, we were able to exclude the effects of various curing methods on alkaloid content.…”

Section: Alkaloid Contentmentioning

confidence: 94%

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Genetic variation in alkaloid accumulation in leaves of Nicotiana

Sun

Zhang

Guang-hong

et al. 2013

J. Zhejiang Univ. Sci. B

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Alkaloids are plant secondary metabolites that are widely distributed in Nicotiana species and contribute greatly to the quality of tobacco leaves. Some alkaloids, such as nornicotine and myosmine, have adverse effects on human health. To reduce the content of harmful alkaloids in tobacco leaves through conventional breeding, a genetic study of the alkaloid variation among different genotypes is required. In this study, alkaloid profiles in leaves of five Nicotiana tabacum cultivars and Nicotiana tomentosiformis were investigated. Six alkaloids were identified from all six genotypes via gas chromatograph-mass spectrometry (GC-MS). Significant differences in alkaloid content were observed both among different leaf positions and among cultivars. The contents of nornicotine and myosmine were positively and significantly correlated (R 2 =0.881), and were also separated from those of other alkaloids by clustering. Thus, the genotype plays a major role in alkaloid accumulation, indicating a high potential for manipulation of alkaloid content through traditional breeding.

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Section: Alkaloid Contentsupporting

confidence: 93%

Section: Alkaloid Contentmentioning

confidence: 94%

Genetic variation in alkaloid accumulation in leaves of Nicotiana

Sun

Zhang

Guang-hong

et al. 2013

J. Zhejiang Univ. Sci. B

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“…Several publications have suggested alkaloid levels and their composition to be of greater importance to TSNA formation as compared to NO 3 -N levels. 16,17 Burton et al, 37,38 however, did not observe significant correlations between TSNAs and alkaloids or NO 3 -N. Instead, these workers observed greater correlations between TNSA accumulation and levels of nitrite, suggesting that nitrite is the limiting factor in TSNA formation in air-cured tobacco. It seems logical that levels of alkaloids, leaf NO 3 -N, and leaf nitrite all play roles in TSNA formation.…”

Section: ■ Discussionmentioning

confidence: 90%

“…Reductions in total TSNAs can be achieved through the use of tobacco lines with reduced genetic potential to accumulate alkaloids, in general. 16,17 Specific reductions in NNN can be achieved by reducing the quantity of the nornicotine precursor through conventional selection, 18 genetic engineering, 19 or introduction of deleterious mutations into genes encoding for enzymes involved in the biosynthesis of this alkaloid. 20 Additional strategies to reduce TSNAs might involve methods to reduce the availability of nitrosating agents.…”

Section: ■ Introductionmentioning

confidence: 99%

Impact of Alleles at the Yellow Burley (Yb) Loci and Nitrogen Fertilization Rate on Nitrogen Utilization Efficiency and Tobacco-Specific Nitrosamine (TSNA) Formation in Air-Cured Tobacco

Lewis

Parker

Danehower

et al. 2012

J. Agric. Food Chem.

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Tobacco-specific nitrosamine (TSNA) formation in tobacco is influenced by alkaloid levels and the availability of nitrosating agents. Tobacco types differ in their potential for TSNA accumulation due to genetic, agronomic, and curing factors. Highest TSNA concentrations are typically measured in burley tobaccos. One of the main genetic differences between burley and all other tobacco types is that this tobacco type is homozygous for recessive mutant alleles at the Yellow Burley 1 (Yb(1)) and Yellow Burley 2 (Yb(2)) loci. In addition, burley tobacco is typically fertilized at higher nitrogen (N) rates than most other tobacco types. This study utilized nearly isogenic lines (NILs) differing for the presence of dominant or recessive alleles at the Yb(1) and Yb(2) loci to investigate the potential influence of genes at these loci on TSNA accumulation. Three pairs of NILs were evaluated at three different nitrogen fertilization rates for alkaloid levels, nitrogen physiology measures, and TSNA accumulation after air-curing. As previously observed by others, positive correlations were observed between N application rates and TSNA accumulation. Recessive alleles at Yb(1) and Yb(2) were associated with increased alkaloid levels, reduced nitrogen use efficiency, reduced nitrogen utilization efficiency, and increased leaf nitrate nitrogen (NO(3)-N). Acting together, these factors contributed to significantly greater TSNA levels in genotypes possessing the recessive alleles at these two loci relative to those carrying the dominant alleles. The chlorophyll-deficient phenotype conferred by the recessive yb(1) and yb(2) alleles probably contributes in a substantial way to increase available NO(3)-N during curing and, consequently, increased potential for TSNA formation.

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“…Storage in elevated temperatures for longer than four weeks results in higher amounts of TSNA (Brunnemann et al, 1996). Curing specifically has a huge impact on increasing the levels and the concentration ranges of NNN and NNK in cured leaves of commercial Nicotiana species (N. tabacum and N. rustica) have been reported to be increased by 6 fold compared to concentration in fresh green leaves (Djordjevic et al, 1989b, International Agency for Research on Cancer, 2007. Up to 3 mg of NNN and NNK could be present in each gram of a smokeless tobacco from Sudan which is called toombak (Idris et al, 1991).…”

Section: Tobacco Specific N-nitrosamines (Tsnas)mentioning

confidence: 99%

Investigations into the pituri plant: nicotine content, nicotine conversion to nornicotine, nicotine release and cytotoxicity of Australian native Nicotiana spp.

Moghbel¹

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The Aboriginal population of Central Australia use endemic Nicotiana spp. to make a smokeless tobacco product known as pituri that they chew/suck for nicotine absorption. This thesis describes the relative abundance of nicotine alkaloids amongst Australian Nicotiana spp., with special focus on the molecular characteristics of nicotine to nornicotine conversion.The most popular chewed species, N. gossei, is investigated for nicotine release and cytotoxicity in comparison to similar products to gain insight into potential hazards to pituri users.To analyse the alkaloids of Nicotiana leaves, a HPLC-UV method was developed to separate and quantify six closely related alkaloids (nicotine, nornicotine, anatabine, anabasine, myosmine, cotinine). A C18 column with a mobile phase of ammonium formate buffer (pH 10.5) separated the six alkaloids within 13 min with detection at 260 nm. Linearity, precision and reproducibility were satisfactory. The limit of quantification was 2.8 and 4.8 µg/mL for nornicotine and nicotine, respectively, and below 2 µg/mL for other alkaloids. This method quantifies more alkaloids and in less time than previously reported methods.Tobacco alkaloids are responsible in formation of carcinogenic tobacco specific nitrosamines such as N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). To quantify NNN and NNK, a fast LC-MS/MS method was developed using a HILIC column with a triple quadrupole tandem mass spectrometry. The linearity, accuracy, recovery and repeatability for this method were satisfactory, with quantification limit of 2.6 and 4.3 ng/mL for NNN and NNK, respectively. Nornicotine results from demethylation of nicotine, and is associated with negative effects on health. A group of cytochrome P450 genes that are mainly expressed during senescence or drying is involved in this conversion. The conversion loci were amplified in all studied 24 taxa, and sequenced in 6 selected species that contrast in conversion phenotype. Transcript accumulation of the responsible loci in fresh versus dried leaves of low or nonconverter N. gossei, N. excelsior and N. benthamiana maintained a steady level or a slight increase, but increased by 3 fold in cured leaves of the high converter N. goodspeedii, N. velutina and N. cavicola. This indicates the presence of functional loci that are triggered by curing only in high ii converter species and poses a potential risk for chewers of these species due to their greater potential for nornicotine production.The release of nicotine from the leaves of N. gossei was compared to that from a Swedish snus, the CORESTA reference smokeless tobacco (CRP2), and Nicabate chewing gum. A model buccal cavity system was developed and three different chewing conditions, performed manually were tested over 120 minutes: no chewing action, initial chewing and chewing at 15-minute intervals. To simulate the effect of alkaline wood ash, the effect of alkaline pH on the release of nicotine from N. gossei dry leaves was also evaluated. Samples ...

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Tobacco-specific nitrosamine accumulation and distribution in flue-cured tobacco alkaloid isolines

Cited by 35 publications

References 13 publications

Genetic variation in alkaloid accumulation in leaves of Nicotiana

Genetic variation in alkaloid accumulation in leaves of Nicotiana

Impact of Alleles at the Yellow Burley (Yb) Loci and Nitrogen Fertilization Rate on Nitrogen Utilization Efficiency and Tobacco-Specific Nitrosamine (TSNA) Formation in Air-Cured Tobacco

Investigations into the pituri plant: nicotine content, nicotine conversion to nornicotine, nicotine release and cytotoxicity of Australian native Nicotiana spp.

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