Gayland F. Spencer

Glucosinolate composition of seeds from 297 species of wild plants

Abstract Seed samples from 22 species of the Capparidaceae (eight genera), one Caricaceae, 259 Cruciferae (88 genera), two Moringaceae, three Phytolaccaceae, one Pittosporaceae, six Resedaceae, one Salvadoraceae and two Tropaeolaceae were analysed for total and individual glucosinolate compositions. Glucosinolates with a wide variety of both alkyl and aryl substituents were quantified by GC of their hydrolysis products and, in certain cases, were confirmed by mass spectrometry.

Volatile monoterpenes inhibit potato tuber sprouting

Several volatile monoterpenes, which are among the major constituents of several easily obtainable essential oils, were phytotoxic in the gaseous phase to emerged potato tuber sprouts. Analyses of the more phytotoxic monoterpenes were conducted using a continuous-flow system in which the compounds were released as volatiles into the headspace surrounding the tubers. Several of these compounds, which have low mammalian toxicities and are currently used in large amounts as flavorings, over-the-counter medications and perfumes, effectively inhibited sprouting and fungal growth at relatively low molar concentrations.CompendioVarios monoterpenos volátiles, que se encuentran entre los principales constituyentes de diversos aceites esenciales fácilmente obtenibles, fueron fitotóxicos en estado gaseoso a los brotes del tubérculo de papa. Se condujeron análisis de los monoterpenos más tóxicos utilizando un sistema de flujo continuo en el cual los compuestos fueron liberados como gases en el espacio superior que rodeaba a los tubérculos. Varios de estos compuestos, que poseen bajas toxicidades para los mamíferos y son utilizados en la actualidad en grandes cantidades como condimentos, medicinas de venta libre y perfumes, inhibieron eficientemente el brotamiento y el crecimiento de hongos a concentraciones molares relativamente bajas.

Naturally-occurring aromatic compounds inhibit potato tuber sprouting

Several naturally-occurring aromatic aldehydes and an aromatic alcohol inhibited potato tuber sprouting when applied as volatiles or directly as emulsions. Exposure to volatiles was for 1 or 10 days prior to placement into fresh air. Salicylaldehyde inhibited sprouting of tubers exposed for 1 or more days; benzaldehyde, cinnamaldehyde, cuminaldehyde and thymol suppressed sprouting of tubers exposed for 10 days. Direct application of cinnamaldehyde and benzaldehyde as 1% and 10% emulsions completely inhibited sprouting 14 days after treatment without apparent tuber damage. These compounds applied without dilution inhibited sprouting but damaged tubers.

A pterocarpan and two isoflavans from alfalfa

Abstract (−)6 aR ,11 aR -Dihydro-3-hydroxy-9,10-dimethoxy-6 H -benzofuro[3,2 c ] [1]-benzopyran (10-methoxymedicarpin), (+)-(2,3,4,-trimethoxyphenyl)-2,3-dihydro-7-hydroxy-4 H -1-benzopyran (7-hydroxy-2′,3′,4′-trimethoxyisoflavan) and (+)-(2,3,4-trimethoxy-5-hydroxyphenyl)-2,3-dihydro-7-hydroxy-4 H -1-benzopyran (7,5′-dihydroxy-2′,3′,4′-trimethoxyisoflavan) were isolated for the first time from dried Medicago sativa hay. Structural assignments were based on 1 H NMR and mass spectra, X-ray crystallography, and optical rotations.

Herbicidal activity of sulforaphene from stock (Matthiola incana).

A herbicidal compound was isolated from extracts ofMatthiola incana and identified as sulforaphene (4-methylsulfinyl-3-butenyl isothiocyanate). The ED50 of this compound against velvetleaf seedlings was approximately 2×10−4 M. Glucoraphenin, the glucosinolate that is the natural precursor of sulforaphene, was less phytotoxic, with an ED50 of near 6×10−3M.

Dimethyl-(4-methyl-1-cyclohexenyl)methyl and 2-(1-Methylethylidene)-5-methylcyclohexyl Ethers from Pulegone1

Abstract NaBH4 reduction of pulegone (1) in short chain alcohols followed by acidification of the reaction mixture gives dimethyl-(4-methyl-1-cyclohexenyl) ethers. Acid catalyzed transetherification of these ethers in longer chain alcohols yields mixtures of the title compounds.