Alkaloid composition of nicotiana rustica strains /

Abstract

The seedings of the various strains were produced under the supervision of Dr. J. E. McMurtrey, Jr., to whom thanks is also due for supplying the information given in Table 1 on the identification and past history of the strains. The analyses of the green plants were conducted by Mr. G. E. LaRoche, and of the cured plants by Mrs. Tamara Sorokin. ii ALKALOID COMPOSITION OF NICOTIANA RUSTICA STRAINS R. N. Jeffrey 1N icotine is generally considered to be the typical alkaloid of the genus Nicotiana, though it is well known (5)-^that different species contain different alkaloids. Studies conducted in this (6) and other (2., 7 , 8) laboratories since more sensitive means of differentiation of alkaloids have become available , have shown that in N. tabacum strains exist which differ in the proportion of nornicotine to nicotine in the green or in the cured leaf. We are not aware of any published report of a similar situation in N. rustiea , so when samples of a considerable number of strains of J$j rustica became available in connection with other work of the Tobacco Section, they were analyzed,, both in the green state and after curing, to determine whether strains which differed significantly in alkaloid composition either before or after curing were present in this collection. Certain information concerning the strains grown is given in Table 1. This includes the source of the seed used and some information as to the previous history of the strain. In most instances additional information is available if needed by an investigator, but nearly all samples lead back to some point where the record is incomplete.

Alkaloid Composition of the Nicotiana Species

“…The principal interest in these works was the kind and amount of alkaloids found in each species. The findings of these independent investigations were in good agreement: [ 1] all observed wild species contained one or more alkaloids, [2] generally, a single alkaloid was found to predominate in a given species, · [3] nicotine or nornicotine occurred as the main alkaloid in most species, but a few species produce anabasine as the principal alkaloid, [ 4] total-alkaloid levels were found to be highly variable, and [5] no clearly defined associations between phylogenetic position and the kinds or amounts of alkaloids was evident. Various techniques for isolation and analysis of alkaloids were used in these investigations.…”

“…In most cases, curing resulted in an increased proportion of nornicotine at the apparent expense of nicotine which decreased, indicating these species have the so-called converter trait ( 6 ). (4,9,10,11,15,16), alkaloid levels and composition were highly variable among the Nicotiana species. For the genus as a whole, there were no immediately obvious associations between alkaloid characteristics and geographic origin, morphology, or chromosome number.…”

“…More than half (11 out of 19) of the differences involved these two alkaloids. As discussed by previous investigators, these differences may be due to the action of genetic factors for converting nicotine to nornicotine under certain cultural and curing conditions (4,14). Other differences involved the identification between nicotine and anabasine and nornicotine versus anabasine.…”

“…Most of the species which are found to contain mainly nornicotine follow the first system of conversion. As indicated, the alkaloid content of the Nicotiana species has been the subject of several previous investigations ( 4,9,10,11,15,16). Duplicate analyses now exist for most species.…”

“…However, the presence of alkaloids in all Nicotiana species is an indication that they may have had some adaptive value to the genus as a whole (14). The alkaloid composition of the Nicotiana species has been the subject of several investigations (4,9,10,11,15,16). The principal interest in these works was the kind and amount of alkaloids found in each species.…”