Chemistry of Essential Oils

(Tuis.) #1

ZINGIBEKACE^S 101


OIL OF ALPINIA GALANGA.
The rhizome and roots of Alpinia galanga yield 004 per cent, of
essential oil having the following characters:—
Specific gravity 0
978 to 0-985
Optical rotation + 4° „ + 6°
Refractive index 1-5164
Acid value 1-8
Ester „ 145-6
The oil contains about 50 per cent, of methyl cinnamate, and 20 to
30 per cent, of eucalyptol. Camphor and d-pinene are also present.


OIL OP ALPINIA MALACCENSIS.
The fresh roots of Alpinia malaccensis yield, according to Schimmel
cCo., about 0 25 per cent, of essential oil having the following char-
acters :—
Specific gravity 1-039 to 1-047 at 27°
Optical rotation.+ 0° 15' to + 1° 30'
Solidifying-point 25-5°
Saponification value 256 to 278-5
Refractive index 1-5477
It contains methyl cinnamate.
The leaves also yield an oil which has been examined by van Bom-
burgh,^1 who obtained 016 per cent, from the fresh leaves. The oil has
the following characters :—
Specific gravity 1-020 at 26°
Optical rotation,.+ 6° 5'
It contains a-pinene, and about 75 per cent, of methyl cinnamate.
OIL OF ALPINIA NUTANS.
The root of this plant yields an essential oil having a specific gravity
0-950 at 29°. It distils principally at a temperature below 230°. The
higher boiling fractions contain an ester of (probably) cinnamic acid.
The oil from the leaves has recently been examined by Kafuku
2
who
obtained 0
053 per cent. It had the following characters :—
Specific gravity at 19° 09301
Optical rotation + 38

Refractive index.1-4750
Saponification value 9-88
„ „ (after acetylation) 36-1
It contains 30 per cent, of d-camphor, 17 per cent, of d-camphene,
cineol, an ester of cinnamic acid, a sesquiterpene, a high boiling
phenol, and probably limonene.
OIL OF CARDAMOMS.
The oils from different kinds of cardamoms, although similar in
general properties, differ to a certain extent chemically. The seeds from
which the oil is distilled are chiefly exported from South-West India
and Ceylon in their pericarps, forming the cardamoms of commerce.
The following description
3
of the principal characters of the more
important varieties of cardamoms is of interest:—
" My sores.—Divided into rounds and longs. The former are what
1
2 Kon. Akad. Weten. Ammerdam (1898), 550.
3 J. Chem. Ind. Tokyo, 20 (1917), 349.
Chemist and Druggist Diary, 1899, 500.

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