The cuticular waxes of a tobacco budworm resistant tobacco, TI-165, contain a series of polar, high molecular weight compounds, which were separated from other components by solvent partitioning and Sephadex LH-20 gel chromatography. Glass capillary gas chromatography (GC-2) of these constituents as trimethylsilyl ethers and GC-2/mass spectrometry indicated that there were six groupings of isomers differing in mass, each from the next by 14 amu. Saponification of the total mixture of compounds yielded sucrose and a series of C2-to C8-aliphatic acids. The major acids were acetic, 2-methylbutyric, and 3-methylvaleric acids. Repeated gel chromatography resulted in the isolation of 6-O-acetyl 2,3,4tri-0-[3-methylvaleryl]-a-D-glucopyranosyl-d-D-fructofuranoside, the major isomer, as defined by NMR and MS data. Other sucrose esters with similar molecular weights were isolated by preparative gas chromatography and saponified, and their acid compositions were determined. Partial hydrolysis of the SE yielded known tetraacylglucopyranosides.
A gel filtration chromatography method was developed for the isolation and concentration of the high molecular weight polynuclear aromatic hydrocarbons (PAH) contained in the most biologically active fraction of cigarette smoke condensate (CSC). The unusually complex mixture of large PAH found in CSC necessitated the use of preparative gas chromatography followed by high-pressure liquid chromatography to achieve separation and identification. Mass spectral, ultra-violet absorption, and chromatographic retention data were needed for the comprehensive identification of the large molecular weight PAH components of CSC. The majority of the more than 200 isolated compounds were identified. Compounds newly identified in CSC included 3,4-dimethylenepyrene, 3,4-trimethylenepyrene, cyclopenta(c,-d)pyrene, 4,5-methylenetriphenylene, benzo[b]perylene, and several dibenzofluoranthenes.
New types of sucrose esters have been synthesized and shown to be potent
insecticides against
sweet potato whiteflies. On the basis of the structures of natural
sucrose esters isolated from various
Nicotiana species and which were shown to be potent whitefly
insecticides, it was decided to
synthesize similar sucrose esters. Specific conditions were worked
out for the reaction of acid chloride
with sucrose to yield a series of mono-, di-, tri-, and tetraacyl
sucroses. As the active sucrose esters
of Nicotiana species contain mainly heptanoic and octanoic
acids esterified to sucrose,
C6−C12
aliphatic acid sucrose esters were prepared. Capillary gas
chromatography of their TMS derivatives
showed that distinct groups of isomers were produced. Separation
by silicic acid chromatography
produced fractions containing individual groups of monoacyl sucroses,
diacyl sucroses, triacyl
sucroses, etc. Evaluations of individual groups of the
C6−C12 acid sucroses showed that
diheptanoyl
sucroses, dioctanoyl sucroses, and dinonanoyl sucroses were most active
against whiteflies and
aphids. Details of syntheses, separations, GC and NMR data, and
whitefly assays are presented.
Keywords: Sugar esters; insecticides; whiteflies; aphids; chromatography;
syntheses; bioassays;
correlation
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