สารบัญ

Thai name มหาหิงคุ์ (MAHAA HINGU)

Category  Carminative; antispasmodic.

               Asafoetida is the oleo-gum-resin obtained by incising or cutting the living rhizome and roots of Ferula assa-foetida L.; F. foetida (Bunge) Regel; F. rubricaulis Boiss., and probably of other species of Ferula (Family Apiaceae).

Constituents  Asafoetida contains about 10 to 17 per cent of volatile oil, 40 to 64 per cent of resin and about 25 per cent of gum.  The main constituent of the oil is (E)-1-propenyl sec-butyl disulfide with a number of related organic disulfides and some terpenes. The resin consists of asaresinotannol, both free and combined with ferulic acid.  Umbelliferone and sesquiterpene coumarins including umbelliprenin and galbanic acid (asacoumarin B) are also present.  

Description  Asafoetida occurs as a soft mass, sometimes almost semi-liquid, or as irregular, more or less pliable masses composed of agglutinated tears embedded in a weak brown to moderate yellowish brown matrix, or as loose ovoid tears, from 0.5 to 4 cm in diameter, with a few vegetable fragments.  It becomes hard and occasionally brittle on drying.  The surface of the freshly fractured tears is white to moderate yellowish brown, changing gradually on exposure to air or light to a strong pink and finally to a moderate yellowish brown or alternatively remaining nearly white.  When moistened with water, the tears become moderate orange to weak yellow.  Odour, powerful, persistent and fetid; taste bitter, alliaceous and acrid.

Other relevant information
 1. The plant yielding asafoetida is native to central Asia, particularly eastern Iran and Afghanistan. 
 2.  Pure asafoetida tear usually contains 65 to 75 per cent of substances soluble in ethanol (90 per cent) and yields about 3 to 5 per cent of ash.

Packaging and storage  Asafoetida shall be kept in tightly closed containers and stored at a temperature not exceeding 25°.

Identification
  A.  Triturate the sample with water:  a yellowish orange emulsion is obtained.  Upon the addition of ammonia TS, the emulsion becomes greenish yellow.
 B.  Heat a fragment of the sample with sulfuric acid:  a reddish brown solution is formed.  Subsequently dilute the solution with water, filter and render it alkaline with ammonia TS:  the solution acquires a purplish blue fluorescence.
 C.  To 10 ml of the ethanolic extract of 2 g of the sample, add a few drops each of phloroglucinol TS and of hydrochloric acid:  a pink colour is produced in the mixture.
 D.  Carry out the test as described in the “Thin-Layer Chromatography” (Appendix 3.1).  
   Standard solution  A solution containing 100 µg per mL of ferulic acid in methanol. 
  Test solution   Extract about 25 g of the sample, in powder, with 100 mL of methanol, shake and filter.  Evaporate the filtrate to obtain a brown extract.  Transfer the extract to a 25-mL volumetric flask.  Add 10 mL of methanol, sonicate for 10 minutes, allow to cool to room temperature, dilute to volume, and mix.
  Adsorbent  Silica gel 60F254 (HPTLC plate) 
   Mobile phase  Toluene, ethyl acetate and formic acid (60:40:10)
  Application volume  Apply 10 µL each of Standard solution and Test solution.
   Development  Allow the solvent front to ascend 8 cm above the line of application.  Dry the developed plate in air. 
  Detection  Examine the plate under ultraviolet light (254 nm).  Spray the plate with anisaldehyde TS, heat at 105° for 5 to 10 minutes and examine under visible light.  Observe the result.
   Results  When examined under ultraviolet light (254 nm), the test solution shows a quenching band due to ferulic acid in the middle of the chromatogram, corresponding in R_f to the band shown by the standard solution. 
   When examined under visible light, the test solution shows a dark purple band due to ferulic acid, corresponding in colour and R_f to the band obtained from the standard solution. 

Acid-insoluble ash  Not more than 3 per cent w/w (Appendix 7.6). 

Total ash  Not more than 15 per cent w/w (Appendix 7.7).

Tests for Adulterants
  Ammoniac  Triturate 500 mg of Asafoetida with 12 mL of water until an emulsion is formed, mix 2 mL of this emulsion with 5 mL of water and add 5 mL of sodium hypobromite TS to form a separate layer:  no yellowish orange to red colour is produced in the mixture upon adding.
 Galbanum  Add to 10 mL of the ethanolic extract of 2 g of Asafoetida enough hydrochloric acid to produce a faint turbidity:  the mixture has a bluish green colour which fades as the mixture stands. 
 Rosin  Triturate 1 g of Asafoetida with 10 mL of petroleum ether (boiling range, 40° to 60°) for 2 minutes, filter into a test-tube, and add to the filtrate 10 mL of a freshly prepared 0.5 per cent w/v solution of copper(II) acetate; shake well and allow the liquids to separate:  the ethereal layer should not show a green colour.

Ethanol-insoluble substance  Not more than 50 per cent w/w.  Place about 5 g, accurately weighed, in a small beaker furnished with a glass rod and tared.  Add 50 mL of ethanol (90 per cent) and boil gently.  Filter the hot solution through a tared filter paper and boil the residue with further quantities of ethanol (90 per cent) until all soluble substances are removed, using the glass rod to disintegrate the insoluble substances.  Wash the filter paper with hot ethanol (90 per cent), transfer the paper to the beaker, dry to constant weight at 100°, and weigh.