Further observations on the paraffins and primary alcohols of plant waxes

The lipids of the common house cricket,Acheta domesticus L. II. Hydrocarbons

The hydrocarbons of the common house cricketAcheta domesticus L. consist ofn-alkanes (4%), 2-methylalkanes (20%), x-methylalkanes (59%), an unidentified series of alkanes (trace), and olefins (16-185). The major n-alkane isn-nonacosane (3.5%). The major 2-methylalkanes are 2-methyloctacosane (8%) and 2-methyltriacontane (11%). The members of the homologous x-methylalkane series consist of mixtures of methylalkanes in which the methyl side-chain is located on the 13th, 15th, and 17th carbon atom in the chain. The major x-methylalkanes are the homologues containing 31 (3%), 33 (6.5%), 35 (12.5%), 37 (27%), and 39 (2.5%) carbon atoms. The olefins are a mixture of straight-chain and 2-methyl-alkenes and alkadienes. The major olefins contain 31 (3%) and 37 (7.5%) carbon atoms.

Chemical and pharmacological observations on some Hebe species

Examination of oven-dried leaves and twigs of four species of Hebe indigenous to New Zealand—H. stricta, H. odora, H. bollonsii and H. corriganii—has revealed D-mannitol and condensed tannins to be major constituents. Identification of some of the minor constituents, namely alkanes, fatty acids and aliphatic alcohols was achieved by means of gas-liquid chromatography. Pharmacological studies with the condensed tannin fractions of H. stricta and H. odora have indicated that the reputation of H. stricta as a constipatory agent is attributable to tannins; this agrees with earlier assumptions.

Composition of suberin-associated waxes from the subterranean storage organs of seven plants : Parsnip, carrot, rutabaga, turnip, red beet, sweet potato and potato

The waxes associated with the suberin in the periderm of the underground storage organs of parsnip (Pastinaca sativa L.), carrot (Daucus carota L.), rutabaga (Brassica napobrassica Mill.), turnip (Brassica rapa L.), red beet (Beta vulgaris L.), sweet potato (Ipomoea batatas L.) and potato (Solanum tuberosum L.) were isolated, fractionated into hydrocarbon, wax ester, free fatty alcohol and free fatty acid fractions, and analyzed by combined gas chromatography and mass spectrometry. The amount of wax extracted from the periderm of the storage organs ranged from 2 to 32 μg/cm(2). The hydrocarbons from the suberin layer have a broader chain-length distribution, a predominance of shorter carbon chains, and a higher proportion of even-numbered carbon chains than the leaf alkanes from the same plants. The major components of the free and esterified fatty alcohols and fatty acids have an even number of carbon atoms, and are similar in chain-length distribution to their counterparts found covalently attached to the suberin polymers; however, these suberin components are shorter in chain length than their cuticular analogues from the leaves. Also extracted from the storage organs were polar components which included fatty alcohols and fatty acids in a conjugated form, and ω-hydroxy acids and dicarboxylic acids. Evidence is presented that removal of the wax from the periderm of whole storage organs results in a decrease in diffusion resistance to moisture.

Interference of alkanes in the gas chromatographic analysis of cannabis products

Leaves of young marihuana plants (Cannabis sativa L.) were found by gas liquid chromatography to contain appreciable amounts of two long-chain alkanes, n-heptacosane and n-nonacosane. These alkanes, along with other straight chain alkanes ranging from C19 to C32 could also be detected as minor components in a variety of other marihuana and hashish samples. Depending on the polarity of the g.l.c. column used, the alkanes may have retention times similar to those of the major cannabinoids and thus interfere with qualitative and quantitative analyses of the latter. The findings indicate that g.l.c. alone cannot be used as an accurate and reliable technique for cannabinoid analysis, unless the alkanes are previously removed. However, the alkane composition may be of additional advantage in determining the origin of seized cannabis samples.

Olefins of high molecular weight in two microscopic algae

The hydrocarbon composition of two algae, a golden-brown (Bot-ryococcus braunii) and a blue-green (Anacystis montana), has been investigated by gas chromatography-mass spectrometry. Both show distributions of aliphatic hydrocarbons of odd carbon numbers in the medium and high ranges of molecular weight, with maxima at n-C(17) and n-C(29) for B. braunii and n-C(17) and n-C(29) for A. montana. With the exception of the n-heptadecane of A. montana all the hydrocarbons are monoenes, dienes, or trienes. Since certain continental sediments and oils show similar distributions of alkanes with respect to carbon number, these organisms may be the precursors of the hydrocarbons in these formations.

Paraffinic Hydrocarbons in Pasture Plants

The gas chromatographicmass spectrometric technique recently developed by Ryhage has been applied to the analysis of paraffins extracted from pasture plants, specifically, whole plant and leaves of spotted bur clover (Medicago arabica). Normal alkanes from C(18) to C(35) have been found. The C(29), C(31), and C(33) normal saturated hydrocarbons predominate and n-C(31) is the major component. In the range from C(24) to C(34) the ratio of alkanes with an even number of carbon atoms to those with an odd number is approximately 8 for the whole plant and 5 for the leaves. The distribution of paraffins is similar to that reported for cattle manure and also resembles that of some soils and sediments.