F. R. Earle

Search for new industrial oils. XIV. Seed oils of labiatae

Seed of 194 species in 56 genera of Labiatae, representing six of the eight subfamilies, were analyzed for oil and protein and for fatty acid composition of the oil. The oils are diverse and include some that contain up to 70% oleic acid, 79% linoleic acid, or 72% linolenic acid. An allenic function occurs in a third of the samples from the subfamily Stachyoideae and in the one sample analyzed from the Prasioideae. A method for determining the allene was devised. Oils fromTeucrium species containtrans unsaturation in unidentified components. Oils from twoLamium species have both allenic andtrans unsaturation. Two species ofThymus appear to produce hydroxy acids.

Search for new industrial oils. VII

Seed oils from 37 plant species in 18 families have been analyzed for fatty acid composition by the isomerization method. The variability encountered is evidenced by the range in content of component acids: from 0–23% for apparent linolenic acid, from 8–74% for apparent linoleic acid, and from 2–88% for apparent oleic acid. Dimorphecolic acid has been found to the extent of approximately 60% in a second species ofDimorphotheca, D. pluvialis (L.) Moench, and in the closely related species,Osteospermum ecklonis (DC.) T. Norl.O. spinescens Thunb. contained instead 30% of a conjugated triene, presumably the same as the 8,10,12-octadecatrienoic reported from the relatedCalendula officinalis L. Oils rich in monoenoic acids are mostly in the Umbelliferae and Araliaceae and presumably contain petroselinic acid as well as oleic.

Search for new industrial oils. XIII. Oils from 102 species of cruciferae

Seed from additional species of Cruciferae have been analyzed for crude protein, oil and fatty acids in the oil. Oils were like those reported earlier from other crucifers, except forCardamine impatiens which is unique among known seed oils because it contains some 25% dihydroxy acids. Erucic acid is present (0.3–55%) in about three-fourths of the 102 samples. Eicosenoic acid is a major constituent (32–53%) in four species and monohydroxy acids (45–72%) in another four. Linolenic acid occurs (2–66%) in oil of all species.

Analyses of Seed Samples from 113 Plant Families

Such classical works as those by Wiesner (15) and Wehmer (14) cover much of the earlier chemical knowledge of plant constituents. More recently, specialized research teamns have expended considerable effort in particular fields of plant eomposition, with emphasis on constituents of pharmaceutical iinportance, such as alkaloids (16), steroids (13), and tranquilizers. The current U. S. Department of Agriculture program of searching for potential new crops to provide raw miiaterials for industry (other than the pharmaceutical industry) is probably the most comprehensive effort of this type ever attempted under coordinated sponsorship of one agency and encompasses botanical, chemical, and agronomic talents. More than 3,000 seed samples from a wide spectrum of the plant kingdom have been screened in this search for new sources of industrial raw materials. The present paper reports analytical results on nearly half of these.3 Similar reports will be published as data are compiled on later accessions. As in the past (1-4, 6-12, 17), reports on oils of unusual composition or on plant groups of special promise will be fortheoming as the screening program progresses. In such a program more leads are developed than can be pursued. It is hoped that analytical data of the type in this paper will stimulate chemists and plant scientists to undertake research on some of the uncultivated or little-known species.

Search for new industrial oils. V. Oils of cruciferae

Seeds from 37 species of plants in the family Cruciferae were analyzed for oil and protein, and the fatty acid composition of the oils was determined by gas-liquid chromatography. Erucic acid, generally considered characteristic of crucifer oils, occurs in about three-fourths of these species in amounts ranging from 3 to 59%. Some oils free of erucic acid contain up to 63% linolenic acid or up to 58% eicosenoic.

Chemical Analyses of Seeds II: Oil and Protein Content of 759 Species

The large plant screening program of the U. S. Department of Agriculture continues to reveal chemical compositions significant both to fundamental understanding of the plant kingdom and to future practical usage of selected species as crop plants. To date more than 5,000 seed samples from 160 plant families have been chemically ana- lyzed. The present paper reports results on 1,010 samples, representing 32 orders, 103 families, 465 genera, and 759 species of seed plants. Presentation of data follows the format used in the first paper of this series (1).

Compositional data on sunflower seed

Comparative data are provided on the composition of achenes from sunflower varieties Armavirec, Peredovik, VNIIMK 8931, Smena, Krasnodarets, Arrowhead and Mingren. Handseparated achene components were analyzed. Kernel oil from seed raised in northern United States or southern Canada typically contains about 70% of linoleic acid. In addition to other common acids, traces of C17, C20, C22, C24 acids and linolenic acid are present. The amino acid composition of sunflower kernel protein suggests that the meal may be a valuable ingredient of high-quality feed or food materials. The hull is primarily cellulose, lignin and pentosans; hull lipid and protein differ in composition from the corresponding kernel constituents.

Search for new industrial oils. VI. Seed oils of the genusLesquerella

Fatty acid composition of seed oil from 14 species of the genusLesquerella has been determined by gas-liquid chromatography. All but two species contain hydroxyeicosenoie acid in amounts ranging from 45 to 74%. The remaining two species contain about 50% C18 hydroxy acids, but none of the C20 hydroxy acid.

Search for new industrial oils. XI. Oils of boraginaceae

Analysis of seed oils from 29 species of the family Boraginaceae revealed widespread occur-rence of 6,9,12-octadecatrienoic and C18 noncon-jugated tetraenoic acids in addition to linolenic and other common C16 and C18 acids. The 6,9,12-octadecatrienoic acid ranged in amount from 0-27%, tetraene from 0-17%, and linolenic acid from 0.3-50%. Iodine values of the oils ranged from 88-225.

Boron trifluoride as catalyst to prepare methyl esters from oils containing unusual acyl groups

The procedure of Metcalfe et al. (3) for the preparation of fatty acid methyl esters, using boron trifluoride as catalyst, is shown to be suitable for use with oils containing fatty acids of unusual structures, such as conjugated unsaturation, hydroxyl or epoxy groups, and cyclopropenes in addition to oils with only the common acids. In some cases, boron trifluoride was less destructive to unusual groups than conventional mineral acid catalysts; in others, derivatives were formed that were suitable for quantitation in subsequent gas chromatographic analysis.