Many Eucalyptus waxes contain as major
components long-chain β-diketones, which may be readily separated from the
rest of the wax as insoluble copper complexes. The most commonly occurring β-diketone
is n-tritriacontan-16,18-dione, but in two species, Eucalyptus risdoni and E.
coccifera, β-diketones of shorter chain length predominate. From the waxes
of several Eucalyptus species a new flavone, 5-hydroxy-
4',7-dimethoxy-6,8-dimethylflavone, and a new triterpene, 11,l2-dehydroursolic
lactone acetate, have been isolated.
Gas chromatography has been used to
determine the chain length distribution of β-diketones, hydrocarbons, and
esters from several waxes. The esterified alcohols of Eucalyptus globulus and
E. risdoni belong to two series-long-chain n-alkan-1-ols of predominantly even
carbon number, and n-alkan-2-ols of medium chain length and predominantly
uneven carbon number (n-C9, n-C11, n-C13, and
n-C15).
A quantitative analysis has been made of
the composition of each of the classes of aliphatic constituents known to exist
in hydrolysed wool wax. These classes consist of α-hydroxy acids, ω-hydroxy
acids, alkanoic acids, monohydric alcohols, and α,β-diols. Each has
been found to contain members of the normal, iso-, and anteiso-homologous
series of compounds.
The analysis was carried out by
saponification of the wax and separation of the constituents into the above
classes which were separately reduced to the corresponding hydrocarbon
mixtures. The composition of these mixtures was determined by gas
chromatographic separation.
S m r y A quantitative examination has been made of the components of hydrolysed beeswax.This was achieved by separation into hydrocarbons, monohydric alcohols, " diols ", acids, and hydroxyacids. The alcohol and acid fractions were reduced to the corresponding hydrocarbon mixtures and these together with the naturally occurring hydrocarbons were examined by gas chromatography, which demonstrated their straight-chain character and gave the chain lengths and percentage composition of the components.
The hydrolytic products of carnauba wax,
previously shown to consist mainly of straight-chain alcohols, α,ω-diols, alkanoic acids, and ω-hydroxyalkanoic
acids, have been reexamined by gas chromatographic methods to provide a
qualitative and quantitative knowledge of the components. These components,
shown to be almost entirely straight chain in character, are largely even
carbon numbered compounds, but odd chain-lengths are present. The hydrocarbons
are likewise of odd and even carbon number with the odd members (90%)
predominating.
An unidentified compound, possibly an
unsaturated steroid diol, has been isolated from the unsaponifiable fraction.
Sugar-cane cuticle wax previously found to
consist of long-chain aldehydes, alcohols, acids, and hydrocarbons (Lamberton
and Redcliffe 1960) has been re-examined by gas chromatography to identify and
estimate the individual constituents. The aldehydes, alcohols, and acids, all
straight chain, are principally of even carbon number in each instance with the
C28 member predominant, but appreciable amounts of odd carbon
homologues are also present. The hydrocarbons are also of odd and even carbon
number but with the odd members in greater amounts and n-heptacosane as the
major hydrocarbon constituent.
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