Dill Oil

Chemical properties

Dill weed oil, which is the most important, is obtained by steam distillation of the dill weed (herb) before the fruits becomemature. Itsmain constituents are ??-phellandrene (10–20%), limonene (30–40%), carvone (30–40%), and the so-called (+)-dill ether (up to 10%). The latter is responsible for the typical organoleptic properties of the dill plant and, thus, of dill weed oil. Annually, ～150 t are produced mainly in the United States and Canada, smaller quantities come from Eastern Europe (Bulgaria, Hungary, Ukraine).

Chemical properties

In North America, there are two forms of dill encountered: Dill weed oil (A. graveolens) and Dill seed oil (A. sowa Robx.) (usually of Indian origin). Dill seed oil is also separately described under Dill Indian (see). (1) Dill weed oil: In the United States, the essential oil is obtained by steam distillation of the fresh herb (stalks, leaves and seeds). American dill weed has a strong, fresh, somewhat spicy, aromatic odor and a warm, slightly burning taste. (2) Dill seed oil: Dill seed oil is obtained by steam distillation of the fruits (seeds). The oil has a caraway-like odor and flavor because of the higher carvone content as compared to dill weed oil.

Physical properties

Dill weed oil: American dill weed oil is a pale-yellow to yellow liquid. Dill seed oil: The oil is a slightly yellow liquid.

Occurrence

Found in the plant of A . graveolens, L. (Fam. Umbelliferae) (Guenther, 1950).

Preparation

By steam distillation of the freshly cut plants of A . graveolens L. (Guenther, 1950).

Definition

Extractives and their physically modified derivatives. Anethum graveolens, Umbelliferae.

Essential oil composition

Dill seed oil: Limonene (5.9%), α-pinene (1.3%), γ-terpinene (0.1%), decanal (0.2%), terpinen-4-ol (0.1%), β-elemene (0.1%), cis-dihydrocarvone and caryophyllene (0.8%), trans-hydrocarone (16.6%), carvone (20.9%), dillapiole (52.5%).
Dill weed oil: The major constituents are carvone (35%), limonene (25%), α-phellandrene (29%), 3,7-dimethyl-4,5,6,7-tetrahydrocoumaran (2.9%). In addition, myristicin, dillapiole and unidentified waxes have been reported.

Pharmacology

Dill oil from parts of the A . graveolens plant at concentrations of 50-100 μg/ml had a spasmolytic effect on smooth muscle (isolated rabbit and guinea-pig intestine and guinea-pig lung) and a 5% emulsion in physiological saline given iv to cats at 5-10 mg/kg increased respiratory volume and depressed blood pressure (Shipochliev, 1968). The spasmolytic effect was considered to be chiefly myotropic.
In nearly 100 haemorrhoidal patients, one-third of whom were young, repeated oral doses and nightly enemas of an aqueous infusion prepared from 20-25 g dill plant (A. graveolens) in 200-250 g water caused complete and lasting reduction of venous knots in 2-3 wk (Freise, 1938).

Safety Profile

Mildly toxic by ingestion. A skin irritant. Mutation data reported. When heated to decomposition it emits acrid smoke and fumes.