Chemistry of Essential Oils

(Tuis.) #1
Below 175° 0.
Between 175°
„ 180°
190
°
„ 200°
„ 210°
„ 220°
Above 280°.

and 180".
„ 190°.
„ 200°.
„ 210°.
„ 220°.
„ 230°.

LABIATE


>..


• • •


»


Nothing distilled

. 10 per cent, was collected



  • 13 „

  • 11

  • 12

  • 18 „ „
    18
    18 , residue


267


Pinene and limonene are probably present. The high boiling-point
of the residual fraction, which has a refractive index of about 1*500,
points to the presence of a sesquiterpene. The oil is not soluble in 70
per cent, alcohol (10 volumes), but dissolves in 2 volumes of 80 per cent,
alcohol.
Other samples of this oil examined had specific gravities up to 0*924
and optical rotations from - 6° to + 10°.
Charabot and Fillet have prepared two samples of Spanish vervain
oil, the one distilled from the dried leaves, the other from the flowers,
the respective yield being 0*184 per cent, and 0*878 per cent. The oil
from the leaves had a rotatory power of - 10° 30', that from the flowers
+ 6° 50'. This latter appeared to be more rich in citral than the
former, containing 70 per cent, and about 10 per cent, of alcohols.

OLL OF LOPHANTHUS BUGOSUS.

This plant is found wild in North America and in Eastern Asia.
The oil has been examined by Vilmorin and Levallois.^1 It is an amber-
yellow liquid, soluble in all proportions of 95 per cent., and in 5 volumes
of 85 per cent, alcohol. It has the following characters :—


Specific gravity at 4°
Optical rotation
Ester value ....
„ „ (after acetylation)

0-962 to 0-967
+ 5° „ + 6°
3-7
7.4
The principal constituent is methyl-chavicol, and it also contains
limonene.

OLL OF LOPHANTHUS ANISATUS.

The herb, Lophanthus anisatus, yields about 0*1 per cent, of essential
oil having an odour t resembling that of tarragon. It has the following
characters:—
Specific gravity
Refractive index ... ...
Optical rotation
Acid value
Ester „


The principal constituent is methyl-chavicol.

OIL OF NEPETA.
Umney and Bennett
2
have examined the oil distilled in Sicily from
the catmint, Nepeta Cataria. It has the following characters :—


Specific gravity 0-927
Optical rotation + 12°

0-948 to 0-964
1-5165


  • 7° 10'
    2-8
    14-0


' Bull. Soc. Chim. (1914), 342.^3 Pharm. Jour., 75 (1905), 861.
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