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(-3)M.

Natural products phytotoxicity A bioassay suitable for small quantities of slightly water-soluble compounds.

A large variety of secondary metabolites that can inhibit germination and/or seedling growth are produced by plants in low quantities. The objective of this study was to develop a bioassay capable of reliably assessing reductions in germination percentage and seedling length of small-seeded plant species caused by exposure to minute quantities of these compounds. The germination and growth of alfalfa (Medicago saliva), annual ryegrass (Lolium multiflorum), and velvetleaf (Abutilon theophrasti) were evaluated against six known phytotoxins from five chemical classes; cinmethylin (a herbicidal cineole derivative) was selected as a comparison standard. Each phytotoxin, dissolved in a suitable organic solvent, was placed on water-agar in small tissue culture wells. After the solvent evaporated, imbibed seeds were placed on the agar; after three days, germination percentages and seedling lengths were measured. Compared to a commonly used filter paper procedure, this modified agar bioassay required smaller quantities of compound per seed for comparable bioassay results. This bioassay also readily permitted the measurement of seedling length, a more sensitive indicator of phytotoxicity than germination. Seedling length decreased sigmoidally as the toxin concentration increased logarithmically. Phytotoxicity was a function of both compound and plant species. Cinmethylin, a grass herbicide, reduced the length of annual ryegrass seedlings by 90-100%, whereas that of alfalfa and velvetleaf was inhibited slightly. The agar bioassay facilitated the rapid and reliable testing of slightly water-soluble compounds, requiring only minute quantities of each compound to give reproducible results.

Alchornea cordifolia seed oil: A rich source of a new C20 epoxide, (+)cis-14,15-epoxy-cis-11-eicosenoic acid.

A C20 homolog of vernolic acid has been found at the 50% level inAlchornea cordifolia, Euphorbiaceae, seed oil. This new acid, (+)cis-14,15-epoxy-cis-11-eicosenoic (alchornoic) acid, was isolated by high-pressure liquid chromotography and characterized by mass spectrometry, nuclear magnetic resonance and infrared spectroscopy, optical rotary dispersion, and ozonolysis-gas-chromotography.

Quantitative gas chromatography and gas chromatography-mass spectrometry of Cephalotaxus alkaloids.

Plants of the genus Cephalotaxus contaim many alkaloids, some of which have demonstrated antitumor activity. Analysis of crude alkaloid mixtures by gas chromatography provides quantitation of the active principles and other, non-active, alkaloids. Mass spectrometry is used to identify known alkaloids in extracts and to confirm the presence of previously unknown ones. Such data provide a means for predicting the biological activity of new plant accessions.

Effects of maturity and plant spacing on the morphine content of two varieties of Papaver somniferum L.

Two varieties of opium poppy were grown under irrigation for one season and their capsules analysed for morphine content by gas chromatography. Harvest of the capsules at 29-33 days after flowering (mature seed) gave 6.70 kg/ha morphine as compared to 5.36 kg/ha morphine in capsules harvested at 4-6 days after flowering. With constant row spacing (30 cm between double rows on ridges 102 cm apart), a plant spacing of 6 cm gave 20 per cent more morphine than either 12- or 18-cm spacing. There was no statistical difference in morphine content between a blue- and a white-seeded variety.

Cis-5-polyenoic acids inLarix leptolepis seed oil.

cis-5,cis-9-Octadecadienoic acid (2.7%) andcis-5,cis-9,cis-12-octadecatrienoic acid (24.9%) are present in the seed oil ofLarix leptolepis. The double bond positions were identified by ozonolysis and by gas chromatography-mass spectrometry of methoxy derivatives. Small quantities of branched chain acids of various chain lengths were indicated by gas chromatography. The presence of C17 and C19 branched methyl esters was confirmed by gas chromatography-mass spectrometry.

Occurrence ofCis-6-hexadecenoic acid as the major component ofThunbergia alata seed oil.

An unusual series of monoenoic fatty acids constitutes about 85% of the total acids in seed oil fromThunbergia alata. The major component in the oil,cis-6-hexadecenoic acid (82%), is accompanied by the homologous 4-tetradecenoic (ca. 0.2%) and 8-octadecenoic (1.8%) acids. Another homologous series is represented by 5-tetradecenoic (ca. 0.2%), 7-hexadecenoic (1.8%) and the familiar 9-octadecenoic (4.4%) acids. Traces (<0.1%) of three other acids, 6-tetradecenoic and 10- and 11-octadecenoic, are also present along with palmitic (5.8%), stearic (0.6%) and linoleic (2.2%) acids. Some of the monoenoic acids have not previously been known to occur in seed oils.

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.

TheTrans-6 fatty acids ofPicramnia sellowii seed oil.

The C18 monoenoic acids inPicramnia sellowii Planch. seed oil include bothcis-andtrans-6-octadecenoic acids, as well as oleic acid. The hexadecenoic acids are also thecis- andtrans-Δ6-isomers, and the eicosenoic acids have Δ6-unsaturation of undetermined geometric configuration. The C18 polyenoic acids detected are 9,12- and 6,9-octadecadienoic and 9,12,15- and 6,9,12-octadecatrienoic acids. Partial investigation of another species,P. pentandra Sw., revealed its oil to have a similar fatty acid composition.

Structure and intraglyceride distribution of coriolic acid.

Coriolic [(R)-13-hydroxy-cis-9,trans-11-octadecadienoic] acid (III, R=Z=H) was isolated as the methyl ester from twoCoriaria seed oils in 66 and 68% yields. The double bonds and hydroxyl group were located by periodate-permanganate oxidation before, and chromic acid oxidation after, hydrogenation of the double bonds. Alternatively the positions of the functional groups were indicated by a convenient micro-ozonolysis-gas-liquid chromatographic procedure. Determination of products from partial hydrolysis of theCoriaria oils with pancreatic lipase (EC 3.1.1.3) revealed a preference of the corioloyl group for the 1,3-positions in triglyceride molecules. The possible significance of coriolic acid as an intermediate in the biogenetic conversion of linoleic acid to conjugated trienoic acids is discussed.