Electrospray mass spectrometry for characterization of lipid A from Enterobacter agglomerans.

Negative ion and positive ion electrospray mass spectrometry have been employed to characterize the lipid A mixture produced by hydrolysis of lipopolysaccharides from Enterobacter agglomerans, a Gram-negative bacterium commonly found in field cotton. Neutral monophosphoryl lipid A molecules form stable anions via deprotonation, but adduct formation via cation attachment occurs in low yield. Dephosphorylated lipid A molecules, on the other hand, readily form adducts with Na+, whereas deprotonation occurs in low yield. The mass spectra of lipid A produced by E. agglomerans reveal the presence of lipid A ions which differ in the nature of attached fatty acid side chains. At least two heptaacyl forms of lipid A are present, one of which has a structure which appears to be the same as the structure of heptaacyl lipid A produced by Salmonella minnesota. The second structure differs only by the nature of the side chain at position 3' of the disaccharide backbone where a hydroxymyristoyloxymyristoyl group replaces the myristoyloxymyristoyl substituent. Collisionally activated dissociations prior to mass analysis enable the identification of fragment ions which can be distinguished from at least eight intact deprotonated molecules present in crude lipid A.

252Cf plasma-desorption mass spectrometry of lipid A from Enterobacter agglomerans.

Endotoxins from gram-negative bacteria are believed to be causative agents of byssinosis, an occupational pulmonary disease associated with exposure to cotton dust in textile mills. Lipid A preparations from Enterobacter agglomerans, a gram-negative bacterium commonly found in cotton and cotton dust, have been analyzed using plasma-desorption mass spectrometry. Results indicate the existence of at least two lipid A types which differ only by the presence of an additional oxygen atom whose position has been localized to the acyloxyacyl ester-linked side-chain of the distal portion of the molecule. The lower molecular weight compound of the two structures has the same molecular weight and presumably the same empirical formula as a well-characterized lipid A from Salmonella minnesota. The mass spectra of lipid A compounds obtained from S. minnesota and E. agglomerans show strong similarities. Palmitoyl, hydroxymyristoyl, myristoyl, and lauroyl side-chains which are known to be present in the former are inferred from spectral evidence to be present in the latter.

Effect of alkali treatment on physiological activity of cotton condensed tannin.

Cotton dusts contain condensed tannins and endotoxins, which are suspected of contributing to the development of acute and chronic biological responses in some cotton textile mill workers. Condensed tannin extracted from cotton dust was coated on to cellulose powder, and the tannin coated powder was treated with an alkali solvent system previously developed to reduce the endotoxin content and pulmonary toxicity of cotton dust. Physiological activities of the dusts and powders were compared by assaying the production of the arachidonic acid metabolites prostaglandin F2 alpha (PGF2 alpha), thromboxane A2 (TxA2) (the precursor to thromboxane B2 (TxB2], leukotriene C4 (LTC4), and prostaglandin E2 (PGE2) by guinea pig pulmonary cells obtained by lung lavage. Cotton dust stimulated the pulmonary cells to produce a total of 29 pg metabolites per 10(6) cells. Production of metabolites by cells stimulated with tannin coated cellulose powder was reduced to 8.3 pg/10(6) cells. Alkali treatment of the tannin coated cellulose powder resulted in a further decrease in its ability to stimulate the cells, producing 3.5 pg metabolites per 10(6) cells. The ability of the dusts and powders to stimulate production of metabolites of arachidonic acid by pulmonary cells from guinea pigs was highly correlated with tannin content of the materials, but not with endotoxin content as measured by the Limulus amoebocyte lysate (LAL) assay.

Production of mannitol by fungi from cotton dust.

Cotton dust associated with high pulmonary function decrements contains relatively high levels of mannitol. In this study, cotton leaf and bract tissue and dust isolated from cotton leaf tissue were examined by optical microscopy, scanning electron microscopy, and capillary gas chromatography. Alternaria alternata, Cladosporium herbarum, Epicoccum purpurascens, and Fusarium pallidoroseum were isolated from cotton leaf dust. The fungal samples, cotton dust, and cotton leaf contained mannitol. This study demonstrates that fungi from a late-fall harvest of cotton leaf material produce mannitol and are a probable source of the mannitol found in cotton dust.

Capillary gas chromatography of cotton dusts associated with human pulmonary function studies.

The effects of geographical area of growth and cotton variety on pulmonary activity have been evaluated through human volunteer exposure studies conducted by NIOSH and USDA at the Cotton Quality Research Station, Clemson, S.C. These studies demonstrate that carding California cottons releases dust with less human pulmonary activity than dust released from the corresponding Mississippi cottons. Dust released from Texas cottons grown in 1982 was considerably less active than the dust from Texas cottons grown in 1983. Distinct differences in the chemical compositions of the Mississippi, Texas, and California cardroom dusts were found. Aqueous extracts of the dusts were freeze-dried and then derivatized. Capillary gas chromatography revealed that the California dust extracts and the 1982 Texas dust extract were characterized by relatively higher levels of malic acid, whereas the Mississippi dust extracts and the 1983 Texas dust extracts were characterized by relatively higher mannitol levels.

The chemical composition of standard cotton dust.

Cotton dust samples from Cotton Incorporated were investigated by X-ray fluorescence and proximate analysis methods. These dust samples are known as "standard cotton dust" and have been used by many researchers investigating the causative agent(s) and physiological mechanisms of byssinosis. Silicon, calcium, potassium, and aluminum were present in relatively high concentrations (1-4%) in the dust fractions. The ash content of the dust fractions increased as the fraction particle size decreased. Proximate analyses demonstrate that "noncellulosic organics" are the major class of constituents (35-45%) in cotton dust. Cellulose comprises only 10-15% of the dust, while water-extractable materials comprise approximately 20% of the dust. Capillary gas chromatography performed on silylated, freeze-dried, aqueous extracts of the less than or equal to 38 micron dust fraction revealed the presence of phosphate, malate, arabitol, citrate, fructose, glucose, and mannitol.

Structure-activity relationships for hallucinogenic N,N-dialkyltryptamines: photoelectron spectra and serotonin receptor affinities of methylthio and methylenedioxy derivatives.

Serotonin receptor affinity and photelectron spectral data were obtained on a number of substituted N,N-dimethyltryptamines. Evidence is presented that electron-donating substituents in the 5-position lead to enhanced behavioral disruption activity and serotonin receptor affinity as compared to unsubstituted N,N-dimethyltryptamine and analogues substituted in the 4- or 6-position. Some correlation was found between ionization potentials and behavioral activity, which may have implications concerning the mechanism of receptor binding.

Photoelectron spectra of psychotropic drugs. 6. Relationships between the physical properties and pharmacological actions of amphetamine analogues.

The valence ionization potentials of seven additional members of a series of 2,4,5-trisubstituted amphetamines (1-phenyl-2-aminopropanes) were measured by UV photoelectron spectroscopy. These and previously published data provide experimental measures of the gross electron-donor ability of the aromatic rings of 23 amphetamines. Analogues bearing the 2,5-dimethoxy orientation were found to possess the lowest ionization potentials (IPs); for the analogously X-substituted compounds, the IPs increased in the order of 2,5-(OMe)2-4-X less than 2,4-(OMe)2-5-X less than 4,5-(OMe)2-2-X. Relationships between human psychotomimetic activity (MU), rabbit hyperthermia (SRU), serotonergic receptor affinity (pA2), and charge-transfer complex stabilities (KDNB) were evaluated statistically. A good correlation (r2 = 0.92) was established between the human and rabbit potencies, but poorer correlations were obtained between animal potencies and pA2's (r2 = 0.68-0.69) or KDNB's (r2 = 0.03!). Analysis of the regression relationships between these pharmacological measures and two physical properties, IP and lipid solubility (as modeled by log P), were explored. In general, greater potency is associated with decreasing IP and increasing log P. However, numerous exceptions to single parameter regressions are found. The unusually great potency of the 2,5-(OMe)2-4-X analogues, while qualitatively related to the physical properties, is quantitatively underestimated by these predictors. However, inclusion of a parameter (pi 4) which explicitly acknowledges the type of the 4-substituent leads to much improved correlations. These results support previous suggestions that 4-substituents interact directly with the receptor.

Lysergic acid diethylamide. Photoelectron ionization potentials as indices of behavioral activity.

The photoelectron spectrum of lysergic acid diethylamide (LSD) reveals five ionization potentials (IP's) between 7.25 and 9.75 eV arising from the aromatic (pi) portion of the molecule and IP's of 8.4 eV arising from the tertiary amine and 8.5-9.0 and 9.1 eV arising from the amide group. Comparisons of the IP's of LSD, and of phenethylamines and tryptamines reported by us elsewhere, with activities of these compounds in rat and human behavioral tests show that increasing activity is paralleled by decreasing IP.