A. C. Thompson

Constituents of the cotton bud

Abstract The investigation of the alcohol fraction of the essential oil of cotton ( Gossypium hirsutum L. var. Deltapine Smoothleaf) with an integrated gas-liquid chromatography-mass spectrometry system resulted in the identification of 17 additional alcohols and β-ionone. Tentative assignments were made for 4 other alcohols. None of these has previously been reported in cotton.

Volatile constituents of the boll weevil

Abstract When the distillable oil from adult boll weevils, Anthonomus grandis , of both sexes was investigated with an integrated gas chromatographymass spectrometry system, evidence was obtained for a number of mono- and sesquiterpene hydrocarbons and some substituted anilines including o -toluidine; for some C 5 and C 6 alcohols and monoterpene alcohols; and for at least one sesquiterpene alcohol. The major components were a series of alkanes, alkenes, and alkyl alcohols of high molecular weight. This investigation was part of a study made to identify possible additional components of the pheromone produced by the boll weevil.

The boll weevil‐cotton plant complex

Abstract The boll weevil, Anthonomus grandis Boheman was introduced from Mexico into the United States about 1892. More than three‐fourths of all insect losses to cotton in this country have been attributed to this insect, and it is generally agreed that cotton cannot be profitably grown in areas where it occurs without adequate control measures. This review summarizes the chemically oriented research conducted on this plant‐insect complex during the past seventy years with emphasis on the program conducted since 1962 at the Boll Weevil Research Laboratory. Of plant‐insect relationships, host plant resistance, feeding stimulants, plant attractants, and plant constituents are discussed. Insect‐insect relationships treated include insecticides, chemosterilants and hormones, sex attractants, and insect constituents. The development of an integrated program for the attempted eradication of this insect is also discussed.

A gas chromatographic survey of the volatile fractions of twenty species of insects from eight orders

Abstract The profiles of the essential oil of twenty species of insects from eight orders were obtained by steam distillation and analysis by gas chromatography. For six of the seven species analysed separately by sex, the profiles showed prominent differences. In Coleoptera, phylogenetic similarities were apparent. Sex attractant activity has been reported in only seven of the twenty species investigated.

Sterol galactosides and sterol esters of the cotton bud

About 60% of the total sterols in the cotton bud appeared in the free state; the esterified sterol glycosides contained about 50% saturated fatty acids, largely palmitic acid; the principal unsaturated fatty acid was linolenic acid. β-Sitosterol was the major sterol in all classes of sterol derivatives. The sugar moiety of the esterified sterol glycosides and the sterol glycoside was galactose. Efforts are continuing to evaluate the minor sterols of cotton buds, some of which appear to be hydroxylated ecdysones, and to study their relationship to the development of the Boll weevil,Anthonomus grandis Boheman.

Variations in lipid content of the boll weevil during metamorphosis

Abstract When neutral lipids and phospholipids of the boll weevil, Anthonomus grandis, were studied during the larval-pupal ecdysis, the volume of lipids was found to increase until the pupal stage when it underwent a small decrease. The opposite was true for the phospholipids. The neutral lipids were high in palmitic, palmitaleic, and oleic acids; the phospholipids had large amounts of stearic and linoleic acids. Also, the composition of the phospholipids was qualitatively similar in the larval, pharate pupal, and pupal stages though the larval stage was marked by a predominance of phosphatidyl ethanolamine and a high concentration of linoleic acid in the phosphatidyl choline.

Reaction chromatography : I. Gas-liquid/thin-layer chromatographic derivatization technique for the identification of carbonyl compounds☆

Abstract The technique for the identification of reactive compounds by derivative formation on thin-layer plates at the exhaust of a gas chromatograph (gas-liquid/thin-layer chromatography) was applied to alcohols. Advantages, limitations, and reaction conditions for 3,5-dinitrobenzoates (DNBs) and o -nitrophenylurethans (ONPUs) as derivatives of representative alcohols used in this study are discussed and thin-layer chromatographic behavior in several systems is tabulated. DNBs are readily formed from 0.5 mg and ONPUs from 0.05 mg of the same primary and secondary alcohols. Some tertiary alcohols failed to give either derivative from 10 mg of reactant, while 0.5–5 mg of other reacted discernibly.

Phospholipid composition of the boll weevil,Anthonomus grandis boheman

When phospholipids of newly-emerged adults of the boll weevil,Anthonomus grandis Boheman, were studied in detail, phosphatidyl choline and phosphatidyl ethanolamine were found to be the major phospholipids; sphingomyelin and cardiolipin were present in smaller amounts, and four other minor components were identified. Fatty acid analyses performed on the intact phospholipids and on the enzyme degradation products of phosphatidyl choline and phosphatidyl ethanolamine demonstrated that oleic and linoleic acids were the major fatty acids present in the glycerophosphatides; the sphingomyelin contained fatty acids in the range of 20–22 carbons.

Constituents of the boll weevil, anthonomus grandis boheman—III lipids and fatty acids of subcellular particles of pupae

Abstract 1. 1. Phospholipids were the principal lipids in the microsomes, nuclei and mitochondria of the boll weevil, Anthonomus grandis Boheman. 2. 2. The major fatty acid in the phospholipids of the boll weevil was octadecadienoic acid (18:2) followed by octadecenoic acid (18:1) and hexadecanoic acid (16:0). The weight of neural lipid varied in the subcellular particles, but the ratios of fatty acids remained the same. 3. 3. Phosphatidyl choline and phosphatidly ethanolamine were present in equal amounts in the mitochondria, and phosphatidyl choline predominated in the other subcellular particles of the boll weevil. 4. 4. Triglycerides made up about 50 per cent of the neutral lipids of the nuclei, microsomes and cytoplasm. The principal neutral lipids of the cell mitochondria were diglycerides and monoglycerides.

Constituents of the cotton bud—VII. : Identification of the anthocyanin as chrysanthemin☆

Abstract The only anthocyanin m cotton buds and flowers of Gossypium hirsutum L., var. Delta Pine Smooth Leaf, was identified as chrysanthemin, the 3-β-monoglucoside of cynidin. Buds and flowers contained 0-030 and 0-041 per cent pigment, respectively.