An oligomer from flaxseed composed of secoisolariciresinoldiglucoside and 3-hydroxy-3-methyl glutaric acid residues.

A straight-chain oligomeric structure composed of five secoisolariciresinoldiglucoside (SDG) residues interconnected by four 3-hydroxy-3-methyl glutaric acid (HMGA) residues (molecular weight ca. 4000 Da) was assigned to the main lignan of flaxseed on the basis of nuclear magnetic resonance spectroscopy (NMR).

Pyrone and pyridone compounds in the liquid culture of Physisporinus sanguinolentus.

Chromatographic separation of the liquid culture filtrate of the basidiomycete fungus Physisporinus sanguinolentus has yielded three new compounds viz., 2-methyl-4-pyrone, 2-methyl-5,6-dihydro-4-pyrone and the pyridone form of 4-hydroxy-2-methylpyridine, together with the known triacetic acid lactone, the sesquiterpene dialdehyde merulidial and a derivative of merulidial. Their structures were elucidated by spectroscopic analysis and by comparison to literature data and a synthetic sample. One of the compounds, merulidial, was shown to inhibit the germination of spores and the hyphal growth of the wood-rotting basidiomycete Heterobasidion annosum and the saprophytic mould Cladosporium cucumerinum.

Identification of a sucrose diester of a substituted beta-truxinic acid in oats.

A novel compound, 4,4'-dihydroxy-3,3'-dimethoxy-beta-truxinic acid esterified to sucrose through the fructosyl 3-and 6-carbons (1), was isolated from oat grains (Avena sativa L.). Its structure was determined by a combination of mass spectrometry and 1-D and 2-D NMR. The amounts of 1 in groats of six different oat cultivars ranged from 101 to 150 microg g(-1) (dry wt). None was detected in the hulls. The free diacid, 4,4'-dihydroxy-3,3'-dimethoxy-beta-truxinic acid (2), could not be detected in groats nor in hulls.

HPLC method for analysis of secoisolariciresinol diglucoside in flaxseeds.

A method was developed for the analysis of secoisolariciresinol diglucoside (SDG) in flaxseeds. The analytical method involves extraction of defatted flaxseed flour with dioxane/ethanol, aqueous base-hydrolysis, solid-phase purification of an SDG-containing fraction, and quantitative analysis by high-performance liquid chromatography (HPLC). Pure SDG was isolated from flaxseed using different column chromatographic methods and used, as external standard, for the calibration of the method and for quantification. The method was then applied to study the variation in SDG content in flaxseeds from 14 cultivars grown in Sweden and 15 cultivars grown in Denmark. The SDG content varied between 11.7 and 24.1 mg/g in defatted flaxseed flour and between 6.1 and 13.3 mg/g in whole flaxseeds.

Streptomyces halstedii K122 produces the antifungal compounds bafilomycin B1 and C1.

Streptomyces halstedii K122 was previously found to produce antifungal compounds on solid substrates that inhibit radial growth of fungi among Ascomycetes, Basidiomycetes, Deuteromycetes, Oomycetes, and Zygomycetes, and strongly affected hyphal branching and morphology. During growth of S. halstedii K122 in submerged culture, no antifungal activity could be detected. However, cultivation of S. halstedii in thin (1 mm) liquid substrate layers in large surface-area tissue culture flasks caused intense growth and sporulation of S. halstedii K122, and the biologically active compounds could be extracted from the mycelium with methanol. Antifungal compounds were purified using C18 solid phase extraction and silica gel column chromatography, and identified as bafilomycins B1 and C1, using 2D NMR and FAB MS. Production of bafilomycins, which are specific inhibitors of vacuolar ATPases, has not been reported from S. halstedii previously. Minimum inhibitory concentrations (MIC) of bafilomycins B1 and C1, amphotericin B, and nikkomycin Z were determined at pH 5.5 and 7.0 for the target fungi Aspergillus fumigatus, Mucor hiemalis, Penicillium roqueforti, and Paecilomyces variotii. Penicillium roqueforti was the most sensitive species to all the compounds investigated. The MIC values for amphotericin B were 0.5-4 micrograms.mL-1 for the fungi tested, and pH did not affect the toxicity. The MIC values for nikkomycin Z ranged from < 0.5 microgram.mL-1 for Mucor hiemalis to > 500 micrograms.mL-1 for Aspergillus fumigatus, and pH had no influence on toxicity. Bafilomycins B1 and C1 were equally active against the fungal species tested, with MIC values in the range of < 0.5-64 micrograms.mL-1. All fungi were more sensitive to both bafilomycin B1 and C1 at pH 7.0 than at pH 5.5.

Triterpenoid saponins from Quillaja saponaria.

Three new saponins were isolated from a commercial bark extract of Quillaja saponaria Molina. These compounds were also obtained as degradation products from larger saponins in this extract when treated with strong alkali. The compounds were characterized, using mainly NMR spectroscopy, mass spectrometry and chemical methods, as quillaic acid 3-O-¿beta-D-galactopyranosyl-(1-->2)-beta-D-glucopyranosiduronic acid¿, 3-O-¿alpha-L-rhamnopyranosyl-(1-->3)-[beta-D-galactopyranosyl-(1-->2)] -beta-D-glucopyranosiduronic acid¿ and 3-O-¿beta-D-xylopyranosyl-(1-->3)-[beta-D-galactopyranosyl -(1-->2)]-beta-D-glucopyranosiduronic acid¿, respectively.

Phenolic extractives from root bark of Picea abies.

Five new compounds, viz. 3,4-dimethoxyphenyl 2-O-(3-O-methyl-alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside, 4'-hydroxyphenacyl beta-D-glucopyranoside, (2R,3R)-2,3-dihydro-7-hydroxy-2-(4'- hydroxy-3'-methoxyphenyl)- 3-hydroxymethyl-5-benzofuranpropanol 4'-O-(3-O-methyl-alpha-L-rhamnopyranoside), 1-(4'-hydroxy-3'-methoxyphenyl)-2-[4"-(3-hydroxypropyl)-2"-methoxyphe noxy]-1,3-propanediol 4'-O-beta-D-xylopyranoside and 3'-O-methylcatechin 7-O-beta-D-glucopyranoside, together with several known compounds were isolated from the root bark of Picea abies. The structures were elucidated on the basis of chemical and spectroscopic evidence.

Influence of climatic and edaphic factors on persistence of glyphosate and 2,4-D in forest soils.

Persistence in soil of the two herbicides glyphosate and 2,4-D was investigated after application for brush control in conifer reforestation areas. Field experiments were carried out at five sites in southern Sweden and six in northern Sweden. Initially, glyphosate disappeared faster in northern soils than in southern soils. This was probably a result of the higher biological activity in the northern soils. However, small amounts of glyphosate were detected in the northern area long after all traces had disappeared in the south, presumably because of the long period during which the soil remained frozen in the northern area and because of the slow release of vegetation-bound herbicide. One metabolite of glyphosate, aminomethylphosphonic acid (AMPA), persisted longer than glyphosate itself. After 2 years, 8% of the theoretical amount was found in the northern area and, after 1 year, 1% in the southern area. 2,4-D disappeared rapidly from all sites, although minor amounts persisted for several years, probably because of slow release from vegetation-bound residues.