Title of Invention

A PROCESS FOR THE ISOLATION OF ESSENTIAL OIL FROM AMBRETTE SEEDS

Abstract This invention provides a process for isolation of essential oil from ambrette seeds. This invention leads to the production of ambrette essential oil in higher yields and as close to the composition as its natural occurrence with little or minimum production of side products and with a superior flavour value.
Full Text This invention relates to a process for isolation of essential oil from ambrette seeds. This invention leads to the production of ambrette essential oil in higher yields and as close to the composition as its natural occurrence with little or minimum production of side products and with a superior flavour value.
Abelmoschus moschatus Linn Syn. Hybiscus Abelmoschus of family Malvaceae, popularly known as ambrette is native to India. It is cultivated in tropical regions of Asia, Africa and South America mainly for seeds, which have a characteristic musk odour. The essential oil is widely used as a fixative in fragrance formulations. The liquid oil is a valuable adjunct to high grade perfume compositions to which it imparts a strong and characteristic musk note. It possesses a much smoother note than synthetic musk compounds. The liquid oil of commerce is noted for its rich, sweet floral-musky distinctly wine like odor with a bouquet and 'roundness' rarely found in any other perfumery material and a tenacity of odour that is almost incredible. While the synthetic musk compounds have been shown to cause photo sensitivity and dermatitis in sensitive individuals, the extracts of ambrette seeds have been classified as Generally Recognized As Safe (GRAS) for use in baked foods, candies and alcoholic beverages. Abrettolide and farnesyl acetate are reported to be non-toxic.
The product of commerce presently available is the essential oil obtained by steam distillation of crushed or uncrushed seeds, which immediately after distillation possesses a disagreeable note. It needs to be stored for several months before it matures and becomes suitable for use in blending.
Another procedure described in the literature are extraction of crushed seeds with halogenated solvents CH2CC12 or forane and hydro distillation of the oleoresin. A third

procedure comprises of extraction of coarsely broken seeds with rectified spirit and partial separation of lipids by chilling at 0° C.
In the hitherto known processes, especially the first two, the essential oil is obtained by direct hydro distillation of seeds or its oleoresin involving direct contact with steam. They produce essential oils containing high amounts of farnesol obtained by hydrolysis of the major constituent farnesyl acetate. Abrettolide(s) responsible for the characteristic musk odour also gets partly hydrolysed. These data is presented in the following table.
Recovery of Essential oil of Ambrette seeds by different methods:
(Table Removed)
The main object of the present invention is to provide a cold process for the
extraction of fragrance components in ambrette seeds and their isolation as
close to the nature as possible and in improved yields.
The novelty in the present invention resides in the production of fragrant
essential oil from ambrette seeds, in higher yields and in superior quality close
to its natural occurrence, and suitability of the extracted seeds for recovery of
fatty oil.
Accordingly the present invention provides a process for the isolation of
essential oil from ambrette seeds which comprises:
extracting the ambrette seeds with a low molecular weight C-i - C4 alcoholic
solvent in a solid to liquid ratio ranging from 1:2 to 1:7 in a reactor under
stirring for a period of 1 to 8 hrs at a temperature ranging between 20° - 30°C,
removing the solvent from the above said alcoholic extract under vacuo to
obtain the oleoresin followed by liquid-liquid extraction of the said oleoresin
with a hydrocarbon or a chlorinated hydrocarbon solvent as herein described
to isolate the essential oil from the polar glycosides and pectins, purifying the
above said essential oil by treating it with a suitable adsorbent as defined
herein and further removing the solvent under vacuo to obtain the desired
essential oil with a superior odour profile.
In an embodiment of the present invention the alcoholic solvent used is
selected from the group consisting of methanol, ethanol, propanols and
butanols.i
In yet another embodiment wherein the extraction is carried out using a co current or a counter current flow.
In yet another embodiment the solvent used for liquid-liquid extraction of the oleoresin is selected from the group consisting of pentane, hexane, heptane, dichloro methane and carbon tetrachloride.
In yet another embodiment the adsorbent used is selected from the group consisting of active charcoal, Fuller's earth, silica gel and alumina.
The following examples are given by the way of illustration of the present invention and therefore should not be construed to limit the scope of the invention.
Example-1
A mixture of 1 kg of air dried ambrette seeds and 3 litres of methanol are stirred in a reactor for 6 hours at 25°C. The methanolic extract and raffinate seeds are separated by filtration and the methanol is recovered by distillation under vacuo. The oleo resin thus obtained weighed 12g. Liquid-liquid extraction of the residue with 60 ml of dichloromethane gave a predominantly non-polar fraction. The solution thus obtained is treated with 5 grams of silica gel and the solution separated from the adsorbent. Complete removal of the dichloromethane solvent afforded 2.9 g. of a colourless to pale yellow oil with a sweet pleasant odour, completely devoid of unpleasant odours. The oil can be used immediately in blending and needs no maturing.

Example-2
A mixture of 1 kg of air dried ambrette seeds and 3 litres of methanol are stirred in a reactor for 4 hours at 300C, The methanolic extract and raffmate seeds are separated by filtration and the methanol is recovered by distillation under vacuo. The oleo resin thus obtained weighed 1 Ig. Liquid-liquid extraction of the residue with 60 ml of hexane gave a predominantly non-polar fraction. The solution thus obtained is treated with 5 grams of silica gel and the solution separated from the adsorbent. Complete removal of the hexane solvent afforded 2.8 g. of a colourless to pale yellow oil with a sweet pleasant odour, completely devoid of unpleasant odours. The oil can be used immediately in blending and needs no maturing.
References:
1. N.Kerschbaum. Ber, 60B, 902-905 (1927).
2. G.Misra, V.N.Sharma, C.R.Mitra and K.N.Kaul., Indian patent No. 72408 (1960)
3. L.Cravo, F.Perinau, A.Gaset, Flav.Fragr. J., 7, 65-67 (1992)




We Claim:
1. A process for the isolation of essential oil from ambrette seeds which
comprises:
extracting the ambrette seeds with a low molecular weight C1 - C4 alcoholic solvent in a solid to liquid ratio ranging from 1:2 to 1:7 in a reactor under stirring for a period of 1 to 8 hrs at a temperature ranging between 20° - 30°C, removing the solvent from the above said alcoholic extract under vacuo to obtain the oleoresin followed by liquid-liquid extraction of the said oleoresin with a hydrocarbon or a chlorinated hydrocarbon solvent as herein described to isolate the essential oil from the polar glycosides and pectins, purifying the above said essential oil by treating it with a suitable adsorbent as defined herein and further removing the solvent under vacuo to obtain the desired essential oil with a superior odour profile.
2. A process as claimed in claim 1 wherein the alcoholic solvent used is
selected from the group consisting of methanol, ethanol, propanol and
butanol.
3. A process as claimed in claims 1 and 2 wherein the extraction is
carried out using a co current or a counter current flow.
4. A process as claimed in claims 1 - 3 wherein the solvent used for
liquid-liquid extraction of the oleoresin is selected from the group
consisting of pentane, hexane, heptane, dichloro methane and carbon
tetrachloride.

5. A process as claimed in claims 1 - 4 wherein the adsorbent used is
selected from the group consisting of active charcoal, Fuller's earth,
silica gel and alumina.
6. A process for the isolation of essential oil from ambrette seeds
substantially as herein described with references to the examples.


Documents:

910-del-2001-abstract.pdf

910-del-2001-claims.pdf

910-del-2001-correspondence-others.pdf

910-del-2001-correspondence-po.pdf

910-del-2001-description (complete).pdf

910-del-2001-form-1.pdf

910-del-2001-form-18.pdf

910-del-2001-form-2.pdf

910-del-2001-form-3.pdf


Patent Number 232936
Indian Patent Application Number 910/DEL/2001
PG Journal Number 13/2009
Publication Date 27-Mar-2009
Grant Date 23-Mar-2009
Date of Filing 03-Sep-2001
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI- 110 001, INDIA
Inventors:
# Inventor's Name Inventor's Address
1 YERRAMALLI RAMACHANDRA RAO REGIONAL RESEARCH LABORATORY, BHUBNESHWAR, ORRISA, INDIA
2 PRASHANTA KUMAR ROUT REGIONAL RESEARCH LABORATORY, BHUBNESHWAR, ORRISA, INDIA
3 KARTIK KUMAR BARIK REGIONAL RESEARCH LABORATORY, BHUBNESHWAR, ORRISA, INDIA
4 KABI SURYA JENA REGIONAL RESEARCH LABORATORY, BHUBNESHWAR, ORRISA, INDIA
PCT International Classification Number C09K 19/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA