Roger W. Miller

(S)-1,2-diacyl-3-acetins: Optically active triglycerides fromEuonymus verrucosus seed oil

The seed oil ofEuonymus verrucosus Scop., family Celastraceae, contains more than 90% 1,2-diacyl-3-acetins (monoacetotriglycerides). The constituent triglyceride acids, other than acetic, are the usual long-chain fatty acids.Thin-layer chromatography (TLC), infrared (IR) and hydrolysis with pancreatic lipase indicate that the acetic acid is esterified exclusively on the outer glycerol carbon atoms. The isolated mixed monoacetotriglycerides exhibit optical rotation caused by asymmetry of the central glycerol carbon atom. Comparison with synthetic products of known configuration shows that the natural material is essentially all (S)-1,2-diacyl-3-acetin.IR, TLC and GLC analyses indicate the presence of monoacetotriglycerides in seven other species of Celastraceae and five species in three other plant families in amounts from 13 to 98%.

Search for new seed oils. XV. Oils of boraginaceae

In a search for a preferred source of γ-linolenic (all-cis-6,9,12-octadecatrienoic) acid, seed oils of 33 species of Boraginaceae were examined. The desired triene was found primarily in the subfamily Boraginoideae in amounts ranging from 0.2 to 18%. Oils of this subfamily also contain 0.2 to 15% of the tetraene, all-cis-6,9,12,15-octadecatetraenoic acid. Total unsaturation and the relative proportions of the common acids varied widely in oils of the family. Monoene predominated in the subfamily Cordioideae, diene in Heliotropioideae, and a diverse composition among the Boraginoideae; seven had iodine values of 200 or above.Cordia verbenacea seed oil was unique among those examined in having 43% of C20 acids and 23% of components more volatile in gas chromatography than the usual triglycerides.

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.

OXYGENATED FATTY ACIDS OF ISANO OIL

Abstract Four new oxygenated acetylenic acid—8-oxo-octadeca-9,11-diynoic ( 1a ), 8-hydroxyoctadeca-10,12-diynoic ( 3a ), 8-oxo-octadeca-9,11-diyn-17-enoic

Composition ofCelastrus orbiculatus seed oil

The seed oil ofCelastrus orbiculatus (family Celastraceae) was reinvestigated to determine whether the benzoic acid that it contains is esterified with glycerol. Unlike acetic acid, benzoic acid is not incorporated in glycerides of this oil but, instead, is esterified with two sesquiterpenoid triols of the empirical formula C15H26O4.trans-Cinnamic acid also is esterified with these triols. Acetic acid is a component of these nonglyceride esters, as well as of the triglycerides. We found no evidence for the occurrence of formic acid in this oil. By countercurrent fractionation, we found that this oil contains 8% “ordinary” triglycerides, 59% mono-acetotriglycerides, and 33% nonglyceride substances.

Cephalomannine; a new antitumour alkaloid from Cephalotaxus mannii

Chemical investigation of the antileukaemic and cytotoxic principles of Cephalotaxus mannii has led to the isolation and characterization of cephalomannine, an alkaloidal taxane derivative structurally unrelated to the harringtonine series of alkaloids characteristic of most Cephalotaxus species.

cis-Enediyne chromophore of isano oil

The nonpolar fatty acids from isano oil have been reinvestigated to determine the source of the UV absorption long attributed to conjugatedcis-enediyne groupings. Proton magnetic resonance and mass spectra of certain fractions supported the occurrence of such structures, but discrete compounds with this grouping were not isolated. Part of this ubiquituous UV absorption ascribed to enediyne was found to be due instead to the same conjugated diynones identified previously in the oxygenated acid fraction of isano oil. The structures of methyl octadeca-9,11-diynoate and methyl isanate were correlated with their proton magnetic resonance, (PMR), carbon-13 magnetic resonance, and mass spectra.

(−)-(S,S)-12-hydroxy-13-octadec-cis-9-enolide, a 14-membered lactone from Crepis conyzaefolia seed oil

Abstract Crepis conyzaefolia (Gouan) Dalle Torre seed oil contains about 3% of (−)-( S , S )-12-hydroxy-13-octadec- cis -9-enolide ( 1 ), a lactone of (−)- threo -12,13-dihydroxyoleic acid. The absolute configuration of the acid has been established as D-12, L-13 (12- S , 13- S ) and the lactone has the same absolute configuration.