Changes in content of sterols, alkaloids, and phenols in flue-cured tobacco during conditions favoring infestation by molds

Abstract

Sterols, alkaloids, and phenols were determined in two samples of flue-cured tobacco (Nicotiana tabacum L.) which differed only in that one sample was heavily infested with the molds Aspergillus niger, Aspergillus flavus, and Penicillium. Total sterol and total alkaloid contents were higher in the moldy tobacco sample; total phenol content was higher in the nonmoldy sample. Differences in amounts of nicotine, chlorogenic acid, rutin, scopolin, caffeic acid, and minor sterol constituents indicated that cured tobacco subjected to conditions favoring mold development may undergo alteration in a number of its chemical constituents.A problem sometimes encountered during post harvest processing of tobacco (Nicotiana tabacum L.) is infestation of leaves in curing barns by molds when the environment is moist and warm. Young and Jeffrey (1943) noted that when tobacco is air-cured under conditions of high relative humidity, leaves mold and their nitrogen composition is significantly different from lamina cured under conditions of lower relative humidity. Since there is evidence that molds such as Aspergillus niger and Aspergillus flavus which commonly infest tobacco are capable of metabolizing or synthesizing sterols (Barton and Bruun, 1951;Vanghelovici and Serban, 1941), alkaloids (Bates. 1938; Erlich, 1917), and phenols (Hay et al., 1961; Simpson et al., 1960;Westlake et al., 1959), it was the objective of this preliminary study to determine whether qualitative or quantitative differences in these three types of compounds occurred in flue-cured tobacco exposed to conditions favorable for mold infestation. MATERIALS AND METHODSPreparation of Tissue Samples. Field-grown Nicotiana tabacum L. var.NC2236 was harvested at maturity, flue-cured, and then divided randomly leaf by leaf into two equal lots of about 1 kg. each. The resulting composite samples were subsequently handled in an identical manner, except that while one sample was maintained under normal storage conditions unfavorable to mold development, the other was brought into high order and kept in a warm glasshouse. To hasten development of the mold, this sample was inoculated with scraps of moldy leaf obtained from curing barn trash. After 3 weeks the sample was removed from the glasshouse and allowed to dry to a keeping condition (moisture content less than or equal to 11%) under atmospheric conditions.Both samples were ground to a homogeneous powder prior to chemical analysis. Moisture contents of the two samples at the time of analysis were approximately 6%.Cultures of Microorganisms. Cultures of the two

Sterol Changes during Germination of Nicotiana tabacum Seeds

“…Therefore, germinating tobacco seeds have the same 3-/3-sterols as reported for mature tobacco leaves (8,14); however, the quantitative composition was quite different.…”

“…Serial elution was carried out as follows: 50 ml of n-hexane followed by 50 ml of 10% benzene in n-hexane (discarded), 100 ml of 40% benzene in n-hexane (steryl esters), 50 ml of benzene (discarded) and 100 ml of chloroform (free sterols). The steryl esters and steryl glycosides were hydrolyzed, extracted as described previously (2), and precipitated with digitonin (14).…”

Multi‐element and multi‐site isotopic analysis of nicotine from tobacco leaves

“…The use of a strong base, while allowing nicotine extraction from tobacco tissue, lowers its solubility in the aqueous phase and thus facilitates its passage into ether. The nicotine yield was found to be higher with 1 kmol m"^ NaOH than with the Ba(OH)2 saturated solution used by Keller et al (1969) Chemical degradation of nicotine to nicotinic acid (Fig. 3) This procedure was adapted from that of Leete & Siegfried (1957), Two-hundred and fifty milligrams of nicotine was dissolved in 20 cm^^ of concentrated nitric acid and heated at 100 °C for 24 h. The solution was evaporated to dryness in vacuo and the residue redissolved in 15 cm"* of water.…”

Effect of Light on Mevalonic Acid Incorporation into the Phytosterols of Nicotiana tabacum L. Seedlings

“…110 ters), 50 ml of benzene (discarded), and 100 ml of chloroform (free sterols). The steryl esters and steryl glycosides were hydrolyzed and extracted (5), and the sterols were precipitated with digitonin (17).…”