Larry W. Tjarks

Hydroxy acids and estolide triglycerides ofHeliophila amplexicaulis L.f. Seed oil

Thirty percent of the fatty acids fromHeliophila amplexicaulis seed oil are hydroxy acids, primarily lesquerolic acid (14-hydroxy-cis-11-eicosenoic acid) with a trace of a new fatty acid, 16-hydroxy-cis-13-docosenoic acid. The hydroxy acids in the oil are found exclusively in the 1 and/or 3 positions of the triglycerides and are completely acylated with C20 or C22 saturated or monoenoic acids.

OxygenatedTrans-3-olefinic acids in aStenachaenium seed oil

Interesting differences were found in oils from two samples ofStenachaenium macrocephalum (Compositae) seed with dissimilar storage histories. One contained significant amounts of epoxy acids (6.5%) and hydroxy conjugated dienoic acids (5.6%), but the other contained no more than 1% of these oxygenated acids. Characterization of components in the former oil established that the principal epoxy acid (4.0%) is the previously unknowncis-9, 10-epoxy-trans-3,cis-12-octadecadienoic acid. The conjugated dienols include two additional new acids with Δ3 unsaturation (2.5%): 9-hydroxy-trans-3,-trans-10,cis-12-octadecatrienoic and 13-hydroxy-trans-3,cis-9,trans-11-octadecatrienoic acoids. The nonoxygenated acids, except for the large amount (40%) oftrans-3,cis-9,cis-12-octadecatrienoic, are those that commonly occur in seed oils.

Germination inhibition by 5,7-dihydroxychromone, a flavanoid decomposition product

Abstract5,7-Dihydroxychromone1 isolated from seeds ofPolygonum lapathifolium L. inhibits the germination of velvetleaf (Abutilon theophrasti Medic) seeds. Effective molar concentrations ranged from 1 mM to 6 mM. Flavanoids reported or suspected to cause inhibition were not active at concentrations above 10 mM. Compound1 is a flavanoid moiety and can be formed during catabolic degradation, but its role in the allelopathic activity attributed to flavanoids remains to be determined.

Curvularin from Penicillium baradicum baghdadi NRRL 3754, and biological effects

Curvularin, a fungal metabolite similar in chemical structure to zearalenone, a potent estrogen, was tested for its estrogenic effects to gilts. No estrogenicity was observed to 60 kg gilts after feeding curvularin per os at a rate of 10 mg per day for 5 days. Curvularin was also nontoxic to mice and chick embryo.

A synthesis of methyl 4,6-di-O-Methyl-α-d-mannopyranoside

Abstract A new route is described for preparing methyl 4,6-di- O -methyl-α- d -mannopyranoside ( 5 ) via methyl 2,3-di- O - p -tolylsulfonyl-α- d -mannopyranoside ( 3 ) as an intermediate. The retention of the mannopyranoside configuration and ring form was confirmed by proton n.m.r. spectroscopy and by m.s. of peracetylated aldononitrile derivatives. Mass-spectral fragmentation-pathways previously proposed were confirmed for 5- O -acetyl-2,3,4,6-tetra- O -methyl-, 2,5-di- O -acetyl-3,4,6-tri- O -methyl-, and 3,5-di- O -acetyl-2,4,6-tri- O -methyl- d -mannononitrile.

4,4,24-trimethylcholesta-8,14,24(28)-trien-2α,3β,11α,12β-tetrol 12-acetate, 3-sulphate from Fusarium graminearum

Abstract A sterol sulphate [4,4,24-trimethylcholesta-8,14,24(28)-trien-2α,3β,11α,12β-tetrol-12-acetate, 3-sulphate sodium salt] was isolated from white corn grits fermented with Fusarium graminearium NRRL 13166. In accord with its elemental analysis and negative ion fast atom bombardment mass spectrometry, it was of composition C32H49O8SNa. The structure was determined by spectroscopic data [13C NMR, 1H NMR, UV, IR, high resolution mass spectrometry] and conversion of the sterol sulphate to its diacetate and dihydro derivatives. This is the first report of a sterol sulphate from the genus Fusarium.

Preparation and Structure of (E)-1-(3′-Hydroxy-2-Furanyl)-3-(3″-Hydroxy-4″-Methoxyphenyl)-2-Propen-1-One

Abstract A facile procedure is presented for the synthesis of (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2- propen-1-one (6). Galactosylisomaltol (1) was condensed with isovanillin (2) under strong alkaline conditions at 25 [ddot]C to form (E)-1-(3′-O-β-D-galactopyranosyloxy-2′-furanyl)-3-(3″- hydroxy-4″-methoxyphenyl)-2-propen-1-one (4). (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2-propen-1-one (6) was obtained by acid hydrolysis of 4 in a 53.9% yield. This hetero-cyclic 2-propen-1-one was characterized on the basis of spectral data (IR and 1H NMR), physicochemical properties, and conversion to a mono-O-acetyl derivative.