108 THE CHEMISTKY OF ESSENTIAL OILS
OIL OF K^JMPFEBIA ETHELS.
The oil distilled from the tubers of Kampferia ethela has been
examined by Goulding and Roberts,
1
who obtained a total yield of 1'5
per cent., equivalent to 2-0 per cent, on the dry material. The plant
grows in large quantities in the extreme north-east of the Trans-
vaal, and could easily be cultivated. The oil has the following
characters:—•
Specific gravity 0-923 to 0-9437
Optical rotation + 19° 47' „ + 30-4°
Acid value. 1-0 „ 2- 3
Ester , 5 „ 11-5
„ „ (after acetylation) .... 33-6 „ 47-6
The oil is of pale yellowish-brown colour, having a rather pleasant
odour somewhat resembling that of orange flower oil, combined with a
less agreeable smell, recalling that of crushed ivy leaves. On fractional
distillation under low pressure in an atmosphere of carbon dioxide two
fractions were obtained: (1) (42 per cent.) distilling at 160° to 195°;
specific gravity -901; optical rotation - 4° 30'. (2) (25 per cent.) dis-
tilling at 195° to 270°; specific gravity -988 ; optical rotation + 26° 30'.
The residue (33 per cent.) deposited colourless crystals amounting to
about 8 per cent, of the original oil. The first fraction consisted chiefly
of terpenes and cineol. Dipentene was identified by means of the tetra-
bromide (melting-point 124°), and cineol by its iodol additive compound
(melting-point 112°). An estimation of the cineol by the resorcin
method showed that fraction 1 contained 44 per cent., equivalent to
18'5 per cent, of the original oil. Acetic acid was found to be present,
together with a phenolic body having a creosote-like odour, amounting
to 0*6 per cent, of the'original oil. From the second fraction linalol
was isolated and identified by conversion into citrylidene-cyanoacetic
acid, melting at 120° to 121°. A small quantity of methylanthranilic
acid was also separated, melting at 179°, probably present in the form
of its methyl ester. The crystalline substance separated from the por-
tion boiling above 270°, after repeated crystallisation from alcohol, had
a melting-point of 102° and optical rotation + 198° 20' in chloroform
solution. In dilute alcoholic solution it possesses the characteristic
odour resembling crushed ivy leaves, which was noticed in the oil
itself. It is highly unsaturated, and readily combines with about twice
its weight of bromine. It forms a hydroxylamine-oxime melting at
184°, an oxime melting at 166°, and a benzoyl derivative melting at 260
C
with decomposition. The heavy portion of the oil, amounting to 7 per
cent., appeared to consist of a solution of the ketone compound in liquid
constituents of high boiling-point, probably sesquiterpenes. The com-
position of the oil is summarised as follows :—
Per Cent.
Terpenes (dipentenes and probably pinene) ..... 21'8
Cineol 17-2
Ketonic compound (melting-point 102°).13-0
Alcohols (including linalol)
Esters (chiefly methyl methyl-anthranilate)
Phenols
Acids
Residue (probably chiefly sesquiterpene)(chiefly or entirely acetic acid)
ae (probably chiefly sesquiterpe:11-2
1-3
0-5
0*1
34-9
1
Jour. Chem. Soc. (1915), 314.