Foeniculum vulgare (fruit)

Nomenclature

Foeniculum vulgare Mill.   Apiaceae  
Syn. mishreya; shatapushpa  
Standardized common name (English): fennel  
Pinyin name(s): hui xiang; xiao hui xiang (fruit)

Botanical Voucher Specimen

Source: MOBOT, Tropicos.org	Source: Trish Flaster, MSc, Botanical Liaisons, LLC

Organoleptic Characteristics

[Foeniculum vulgare has an] aromatic odor; taste strong, sweet and camphoraceous. The odor of fennel seed is fragrant, its taste warm. sweet, and agreeably aromatic. Source: United States Dispensatory (1918)

Macroscopic Characteristics

Fennel Fruit is the ripe fruit of Foeniculum vulgare, Mill., collected from cultivated plants, and dried. Foeniculum vulgare is a stout, glabrous biennial or perennial, aromatic herb, with leaves dissected into numerous filiform segments. The flowers are in large, flat, terminal umbels, with from thirteen to twenty rays, and destitute both of general and partial involucres. The corolla consists of five petals, which, as well as the stamens, are golden yellow. The fruit is ovate, and of a dark color, especially in the grooves. Mericarps usually separate, each being broadly elliptical, more or less curved, from 4 to 10 mm. in length and from 1 to 3.5 mm. in breadth, some having a slender stalk from 2 to 10 mm. in length; dorsal surface convex, yellowish-green to grayish brown, with three prominent, longitudinal primary ribs and at the summit a short, conical stylopodium; commissural surface with three narrow, light brown, longitudinal areas separated by two dark brown or brownish-black areas containing the vittae or oil-tubes; odor and taste aromatic and characteristic. Sweet Fennel bears a general resemblance to F. vulgare, but differs in having its stem somewhat compressed at the base, its radical leaves somewhat distichous, and the number of rays in the umbel only from 6 to 8. It is also a much smaller plant, being only about a foot high; its flowers appear earlier, and its young sweet shoots or turiones are eaten in Italy boiled or as a salad. Seeds are described as small, oblong, straight or slightly curved, from three to ten millimetres long, and from two to four millimetres in diameter. Greenish or greenish-brown. Each of the two mericarps with five prominent principal ridges and six large vittae. Source: United States Dispensatory (1918) Source: PlantaPhile Source: PlantaPhile

Microscopic Characteristics

Under the microscope, transverse sections of Fennel show a pentagonal mericarp, four of the edges being nearly equal and slightly concave, the other or commissural surface being much longer and more or less undulate; cells of the seed-coat closely united with those of the pericarp, giving the section two very distinct areas, the inner and larger portion (endosperm) more or less rounded pentagonal and somewhat reniform, composed of polygonal cells, filled with aleurone grains containing rosette aggregates of calcium oxalate and a thin protoplasmic layer enclosing a fixed oil; the outer or pericarp layer distinguished by large elliptical vittae with thick, brown walls, occurring singly and alternating with the primary ribs, and two vittae on the dorsal surface, making usually six vittae in all, there sometimes being, however, one or two vittae additional; in the central portion of each of the ribs occurs a nearly circular, fibro-vascular bundle with a few tracheae and numerous thin-walled, strongly lignified sclerenchymatous fibers. The powder is yellowish-brown consisting of irregular angular fragments; tissues of endosperm, colorless, the cells filled with aleurone grains, each containing a rosette aggregate of calcium oxalate, about 0.002 mm. in diameter; fragments containing yellowish-brown vittae, from 0.1 to 0.2 mm. in width; sclerenchymatous fibers few, strongly lignified and with numerous, oblique, simple pores; parenchyma cells with more or less thick walls and simple pores and occasionally reticulately thickened; tracheae few and either spiral or annular; in mounts made with hydrated chloral T.S., numerous globules of a fixed oil separate. Source: United States Dispensatory (1918) Yellow fragments of a wide secretory canal of Foeniculum vulgare fruit observed at 400x with Acidified Chloral Hydrate Glycerol Solution. Source: Elan M. Sudberg, Alkemist Laboratories Cells of the mericarp from Foeniculum vulgare fruit observed at 400x with Acidified Chloral Hydrate Glycerol Solution. Source: Elan M. Sudberg, Alkemist Laboratories

High Performance Thin Layer Chromatographic Identification

Sweet Fennel (fruit) HPTLC ID - NP and PEG reagent, UV 366 nm (Image electronically enhanced) Sweet Fennel (fruit) (Foeniculum vulgare ssp. vulgare var. dulce) Lane Assignments Lanes, from left to right (Track, Volume, Sample): 1 µL Bitter Fennel fruit 1 3 µL Bitter Fennel fruit 1 6 µL Bitter Fennel fruit 1 3 µL Bitter Fennel fruit 2 1 µL Sweet Fennel fruit 1 3 µL Sweet Fennel fruit 1 6 µL Sweet Fennel fruit 1 3 µL Sweet Fennel fruit 2 3 / 1µL Rutin, Caffeic acid (with incr. Rf) 3 µL Wild Fennel fruit 4 µL Fennel tea 3 µL Anise fruit 1 3 µL Anise fruit 2 3 µL Caraway fruit 1 3 µL Caraway fruit 2  Reference Sample(s) Reference: Dissolve 3 mg of rutin in 1 mL of methanol. Dissolve 1 mg of caffeic acid in 1 mL of methanol.  Stationary Phase Stationary phase, i.e. Silica gel 60, F254  Mobile Phase Ethyl acetate, formic acid, water 15:1:1 (v/v/v)  Sample Preparation Method Sample: Mix 500 mg of powdered sample with 5 mL of methanol and sonicate for 10 minutes, then centrifuge or filter the solutions and use the supernatants / filtrates as test solutions. Derivatization reagent: NP and PEG reagent, Preparation NP reagent: 1 g of natural products reagent in 200 ml ethyl acetate, Preparation PEG reagent: 10 g of polyethylene glycol 400 in 200 mL dichloromethane, Use: Heat the plate at 100°C for 5 min, dip (time 0, speed 5) while still hot, dry in air.  Detection Method Saturated chamber; developing distance 70 mm from lower edge; relative humidity 33%  Other Notes Images presented in this entry are examples and are not intended to be used as basis for setting specifications for quality control purposes. System suitability test: Rutin: orange fluorescent zone at Rf ~ 0.07; Caffeic acid: light bluish fluorescent zone at Rf ~ 0.77. Identification: Compare result with reference images. The fingerprint of the test solution is similar to that of the corresponding botanical reference sample. Additional weak zones may be present. The chromatogram of the test solution shows a yellow zone at Rf ~ 0.17, a light blue zone at Rf ~ 0.20, a faint yellow zone at Rf ~ 0.26 and a faint blue zone at Rf ~ 0.32. A light blue zone is seen in the center part of the chromatogram at Rf ~ 0.53 (yellow arrow). Test for other species: No intense dark blue zone is seen at Rf ~ 0.78 (white arrow, Bitter Fennel fruit). No light blue zone is seen at Rf ~ 0.62 (red arrow, Anise fruit or Caraway fruit). No brownish zones are seen at Rf ~ 0.32 and 0.38 (green arrows, Caraway fruit). Source: HPTLC Association

Foeniculum vulgare HPTLC ID - Vanillin/H2SO4 Reagent UV 365 nm Fennel (seed) (Foeniculum vulgare) Lane Assignments Lanes, from left to right (Track, Volume, Sample): 1 μL Eugenol ~0.1% in CH3OH 3 μL Foeniculum vulgare-1 (seed) 3 μL Foeniculum vulgare-2 (seed) 3 μL Foeniculum vulgare-3 (seed) 3 μL Foeniculum vulgare-3 (seed) 3 μL Foeniculum vulgare-4 (seed) 3 μL Foeniculum vulgare-5 (seed) 3 μL Foeniculum vulgare-6 (seed) Reference materials used here have been authenticated by macroscopic, microscopic &/or TLC studies according to the reference source cited below held at Alkemists Laboratories, Costa Mesa, CA.  Stationary Phase Silica gel 60, F254, 10 x 10 cm HPTLC plates  Mobile Phase toluene: ethyl acetate [9.5/0.5]  Sample Preparation Method 0.5g+5ml dichloromethane, sonicate/centrifuge/decant, evaporate to dryness with N2, qs 1.0 ml Toluene  Detection Method Vanillin/H2SO4 Reagent -> 110° C 5 min -> UV 365 nm  Reference see British Pharmacopoeia, 2003 Source: Elan M. Sudberg, Alkemist Laboratories

Anise fruit HPTLC ID - NP and PEG reagent, UV 366 nm (Image electronically enhanced) Anise fruit (Pimpinella anisum) Lane Assignments Lanes, from left to right (Track, Volume, Sample): 1 µL Anise fruit 1 3 µL Anise fruit 1 6 µL Anise fruit 1 3 µL Anise fruit 2 1 µL Caraway fruit 1 3 µL Caraway fruit 1 6 µL Caraway fruit 1 3 µL Caraway fruit 2 3 / 1µL Rutin, Caffeic acid (with incr. Rf) 3 µL Bitter Fennel fruit 1 3 µL Bitter Fennel fruit 2 3 µL Sweet Fennel fruit 1 3 µL Sweet Fennel fruit 2 3 µL Wild Fennel fruit 3 µL Fennel tea  Reference Sample(s) Reference: Dissolve 3 mg of rutin in 1 mL of methanol. Dissolve 1 mg of caffeic acid in 1 mL of methanol.  Stationary Phase Stationary phase, i.e. Silica gel 60, F254  Mobile Phase Ethyl acetate, formic acid, water 15:1:1 (v/v/v)  Sample Preparation Method Sample: Mix 500 mg of powdered sample with 5 mL of methanol and sonicate for 10 minutes, then centrifuge or filter the solutions and use the supernatants / filtrates as test solutions. Derivatization reagent: NP and PEG reagent; Preparation NP reagent: 1 g of natural products reagent in 200 mL ethyl acetate; Preparation PEG reagent: 10 g of polyethyleneglycole 400 in 200 mL dichloromethane; Use: Heat for 3 min to 100°C, dip (time 0, speed 5) in NP reagent while still hot, dry, dip in PEG reagent.  Detection Method Saturated chamber; developing distance 70 mm from lower edge; relative humidity 33%  Other Notes Images presented in this entry are examples and are not intended to be used as basis for setting specifications for quality control purposes. System suitability test: Rutin: orange fluorescent zone at Rf ~ 0.07; Caffeic acid: light bluish fluorescent zone at Rf ~ 0.77. Identification: Compare result with reference images. The fingerprint of the test solution is similar to that of the corresponding botanical reference sample. Additional weak zones may be present. In the upper part of the chromatogram there are three prominent zones: a light blue zone at Rf ~ 0.88, a yellow zone at Rf ~ 0.76 and a light blue zone at Rf ~ 0.61. In the lower part of the chromatogram there is a sequence of three zones (yellow, light blue, yellowish) between Rf ~ 0.15 and 0.26. Right above the application position there is a yellow zone. Test for adulteration: In the middle of the chromatogram there are neither yellow zones at Rf ~ 0.32 and Rf ~ 0.38 (red arrows, Caraway fruit) nor a faint dark blue zone at Rf ~ 0.32 (blue arrow, Bitter Fennel fruit) nor a light blue zone at Rf ~ 0.53 (yellow arrow, Sweet Fennel fruit). Source: HPTLC Association

Bitter Fennel (fruit) HPTLC ID - NP and PEG reagent, UV 366 nm (image electronically enhanced) Bitter Fennel (fruit) (Foeniculum vulgare ssp. vulgare var. vulgare) Lane Assignments Lanes, from left to right (Track, Volume, Sample): 1 µL Bitter Fennel fruit 1 3 µL Bitter Fennel fruit 1 6 µL Bitter Fennel fruit 1 3 µL Bitter Fennel fruit 2 1 µL Sweet Fennel fruit 1 3 µL Sweet Fennel fruit 1 6 µL Sweet Fennel fruit 1 3 µL Sweet Fennel fruit 2 3 / 1µL Rutin, caffeic acid (with incr. Rf) 3 µL Wild Fennel fruit 4 µL Fennel tea 3 µL Anise fruit 1 3 µL Anise fruit 2 3 µL Caraway fruit 1 3 µL Caraway fruit 2  Reference Sample(s) Reference: Dissolve 3 mg of rutin in 1 mL of methanol. Dissolve 1 mg of caffeic acid in 1 mL of methanol.  Stationary Phase Stationary phase, i.e. Silica gel 60, F254  Mobile Phase Ethyl acetate, formic acid, water 15:1:1 (v/v/v)  Sample Preparation Method Sample: Mix 500 mg of powdered sample with 5 mL of methanol and sonicate for 10 minutes, then centrifuge or filter the solutions and use the supernatants / filtrates as test solutions. Derivatization reagent: NP and PEG reagent; Preparation NP reagent: 1 g of natural products reagent in 200 mL ethyl acetate; Preparation PEG reagent: 10 g of polyethylene glycol 400 in 200 mL dichloromethane; Use: Heat the plate at 100°C for 5 min, dip (time 0, speed 5) in NP reagent while still hot, dry in air, dip in PEG reagent.  Detection Method Saturated chamber; developing distance 70 mm from lower edge; relative humidity 33%  Other Notes Images presented in this entry are examples and are not intended to be used as basis for setting specifications for quality control purposes. System suitability test: Rutin: orange zone at Rf ~ 0.07; Caffeic acid: light bluish zone at Rf ~ 0.77. Identification: Compare result with reference images. The fingerprint of the test solution is similar to that of the corresponding botanical reference sample. Additional weak zones may be present. The chromatogram of the test solution shows a dark blue zone at Rf ~ 0.78 slightly above the position of reference caffeic acid and a dark blue zone at Rf ~ 0.31 (white arrows). Test for other species: No yellow zone is seen at Rf ~ 0.17 (red arrows, Anise fruit, Sweet Fennel fruit). A light blue zone is neither seen at Rf ~ 0.53 (yellow arrow, Sweet Fennel fruit) nor at Rf ~ 0.62 (yellow arrow, Anise fruit, Caraway fruit). No brownish zones are seen at Rf ~ 0.32 and 0.38 (green arrows, Caraway fruit). Source: HPTLC Association