Angelica archangelica root
Angelicae archangelicae radix
DEFINITION
Whole or cut, carefully dried rhizome and root of Angelica archangelicaL. (syn. A. officinalis Hoffm.).
Content: minimum 2.0mL/kg of essential oil (dried drug).
CHARACTERS
Bitter taste.
IDENTIFICATION
A. The rhizome is greyish-brown or reddish-brown, with transversely annulated thickenings. The base bears greyish-brown or reddish-brown, cylindrical, longitudinally furrowed, occasionally branched roots often with incompletely encircling, transverse ridges. The apex sometimes shows remnants of stem and leaf bases. The fracture is uneven. The transversely cut surface shows a greyish-white, spongy, distinctly radiate bark, in which the secretory channels are visible as brown spots, and a bright yellow or greyish-yellow wood which, in the rhizome, surrounds the greyish or brownish-white pith.
B. Microscopic examination (2.8.23). The powder is brownish-white. Examine under a microscope using chloral hydrate solutionR. The powder shows the following diagnostic characters (Figure 1857.-1): fragments of cork consisting of several layers of thin-walled, greyish-brown or reddish-brown cells, in surface view [C] or in transverse section [E]; large, yellowish-brown secretory channels, whole or fragmented, in transverse section [A] or in longitudinal section [F]; fragments of medullary rays, 2or 4 cells wide[G]; fragments of xylem [B] consisting of lignified vessels with reticulate thickening [Ba] occurring singly or in small groups, and unlignified parenchyma in which some of the cells associated with the vessels are collenchymatously thickened. Examine under a microscope using a 50per centV/V solution of glycerolR. The powder shows numerous, simple starch granules 2-4µm in diameter, free or included in parenchyma cells [D].
C.Examine the chromatograms obtained in the test for other species of Angelica, Levisticum and Ligusticum described in the European Pharmacopoeia.
ResultsA: see below the sequence of zones present in the chromatograms obtained with the reference solution and the test solution. Furthermore, other faint fluorescent zones may be present in the chromatogram obtained with the test solution.
Top of the plate(Z)-Ligustilide: a bluish-white fluorescent zone
______/ ______
Osthole: a blue fluorescent zone / A blue fluorescent zone
Imperatorin: a whitish fluorescent zone / A whitish fluorescent zone
A blue fluorescent zone
______/ ______
3 blue fluorescent zones
Reference solution / Test solution
ResultsB: see below the sequence of zones present in the chromatograms obtained with the reference solution and the test solution. Furthermore, other faint quenching zones may be present in the chromatogram obtained with the test solution.
Top of the plate(Z)-Ligustilide: a blue fluorescent zone
______/ ______
Osthole: a quenching zone / A quenching zone
Imperatorin: a quenching zone / A quenching zone
A quenching zone
______/ ______
Several quenching zones
Reference solution / Test solution
Figure 1857.-1. – Illustration for identification testB of powdered herbal drug of angelica archangelica root
Dandelion root
Taraxaci officinalis radix
DEFINITION
Whole or cut, dried underground parts of Taraxacum officinale F.H.Wigg.
CHARACTERS
Bitter taste.
IDENTIFICATION
A.The dark brown or blackish taproot shows little branching and is deeply wrinkled longitudinally on the outer surface. The thickened crown shows many scars left by the rosette of leaves. The fracture is short. A transverse section shows a greyish-white or brownish cortex containing concentric layers of brownish laticiferous vessels and a porous, pale yellow, non-radiate wood.
B.Reduce to a powder (355) (2.9.12). The powder is yellowish-brown. Examine under a microscope using chloral hydrate solutionR. The powder shows the following diagnostic characters (Figure 1852.-1): fragments of brown or reddish-brown cork, in surface view[G] and transverse section [C] with flattened, thin-walled cells [Ca], sometimes accompanied by parenchyma [Cb]; reticulate lignified vessels [E, J,M]; fragments of parenchyma [A, D, K, L], some containing branched laticiferous vessels, in longitudinal section [Ka] and transverse section [Da]; granular contents of laticiferous vessels [B, H]. Examine under a microscope using glycerolR. The powder shows numerous irregular, angular inulin fragments, free [F] or included in the parenchyma cells [La].
C.Thin-layer chromatography (2.2.27).
Test solution. To 2.0g of the powdered herbal drug (355) (2.9.12) add 10mL of methanolR. Heat in a water-bath at 60°C or sonicate for 10min. Cool and filter.
Reference solution. Dissolve 2mg of chlorogenic acidR and 2mg of rutinR in methanolR and dilute to 20mL with the same solvent.
Plate: TLC silica gel F254 plateR (5-40µm) [or TLC silica gel F254 plateR (2-10µm)].
Mobile phase: anhydrous formic acidR, waterR, ethyl acetateR (10:10:80V/V/V).
Application: 20µL [or 5µL] as bands of 10mm [or 8mm].
Development: over a path of 12cm [or 7cm].
Drying: in air.
Detection: heat at 100°C for 5min; spray with or dip briefly into a 10g/L solution of diphenylboric acid aminoethyl esterR in methanolR and dry at 100°C for 5min; spray with or dip briefly into a 50g/L solution of macrogol 400R in methanolR; heat at 100°C for 5min and examine in ultraviolet light at 365nm.
Results: see below the sequence of zones present in the chromatograms obtained with the reference solution and the test solution. Furthermore, other faint zones may be present in the chromatogram obtained with the test solution.
Top of the plateA light blue zone
______/ ______
Chlorogenic acid: a blue zone / A blue zone (chlorogenic acid)
______/ ______
Rutin: a yellowish-brown zone
Reference solution / Test solution
Figure 1852.-1. – Illustration for identification testB of powdered herbal drug of dandelion root
Devil’s claw root
Harpagophyti radix
DEFINITION
Cut and dried, tuberous secondary roots of Harpagophytum procumbensDC. and/or Harpagophytum zeyheriDecne.
Content: minimum 1.2per cent of harpagoside (C24H30O11; Mr494.5) (dried drug).
CHARACTERS
The root is greyish-brown or dark brown.
IDENTIFICATION
A. It consists of thick, fan-shaped or rounded slices or of roughly crushed discs. The darker outer surface is traversed by tortuous longitudinal wrinkles. The paler cut surface shows a dark cambial zone and xylem bundles distinctly aligned in radial rows. The central cylinder shows fine concentric striations. Seen under a lens, the cut surface presents yellow or brownish-red granules.
B.Reduce to a powder (355) (2.9.12). The powder is brownish-yellow. Examine under a microscope using chloral hydrate solutionR. The powder shows the following diagnostic characters (Figure 1095.-1): fragments of cork consisting of yellowish-brown, thin-walled cells, in surface view[B] and in transverse section [C]; fragments of cortical parenchyma consisting of large, thin-walled cells [E, K, N, P], sometimes containing reddish-brown granular inclusions and isolated yellow droplets (P); fragments of reticulately thickened or pitted vessels [D, F, G,M] and fragments of lignified parenchyma [L], sometimes associated with vessels, from the central cylinder; prism crystals [A] and rare small needles of calcium oxalate in the parenchyma. The powder may also show rectangular or polygonal sclereids with dark reddish-brown contents [H,J]. With a solution of phloroglucinol in hydrochloric acid, the parenchyma turns green.
C.Thin-layer chromatography (2.2.27).
Test solution. Heat 1.0g of the powdered herbal drug (355) (2.9.12) with 10mL of methanolR on a water-bath at 60°C for 10min. Filter and reduce the filtrate to about 2mL under reduced pressure at a temperature not exceeding 40°C.
Reference solution. Dissolve 1mg of harpagosideR and 2.5mg of fructoseR in 1mL of methanolR.
Plate: TLC silica gel plateR (5-40µm) [or TLC silica gel plateR (2-10µm)].
Mobile phase: waterR, methanolR, ethyl acetateR (8:15:77V/V/V).
Application: 20µL [or 5µL] as bands.
Development: over a path of 10cm [or 7.5cm].
Drying: in a current of warm air.
Detection A: examine in ultraviolet light at 254nm.
Results A: see below the sequence of zones present in the chromatograms obtained with the reference solution and the test solution; the chromatogram obtained with the test solution shows other distinct zones, mainly above the zone due to harpagoside. Furthermore, other faint zones may be present in the chromatogram obtained with the test solution.
Top of the plate______/ ______
Harpagoside: a quenching zone / A quenching zone: harpagoside
______/ ______
Reference solution / Test solution
DetectionB: spray with a 10g/L solution of phloroglucinolR in ethanol (96per cent)R and then with hydrochloric acidR; heat at 80°C for 5-10min and examine in daylight.
ResultsB: see below the sequence of zones present in the chromatograms obtained with the reference solution and the test solution; the chromatogram obtained with the test solution also shows several yellow or brown zones above the zone due to harpagoside. Furthermore, other faint zones may be present in the chromatogram obtained with the test solution.
Top of the plate______/ ______
Harpagoside: a green zone / A green zone (harpagoside)
______/ ______
A yellow zone
A light green zone
Fructose: a yellowish-grey zone / A yellowish-grey zone may be present (fructose)
A brown zone
Reference solution / Test solution
Figure 1095.-1. – Illustration for identification testB of powdered herbal drug of devil’s claw root
Ginger
Zingiberis rhizoma
DEFINITION
Dried, whole or cut rhizome of Zingiber officinale Roscoe, with the cork removed, either completely or from the wide, flat surfaces only.
Content: minimum 15mL/kg of essential oil (anhydrous drug).
CHARACTERS
Characteristic aromatic odour.
Spicy and burning taste.
IDENTIFICATION
A. The rhizome is laterally compressed, bearing short, flattened, obovate oblique branches on the upper side, each sometimes having a depressed scar at the apex; the whole rhizomes are about 5-10cm long, 1.5-3cm or 4cm wide and 1-1.5cm thick, sometimes split longitudinally. The scraped rhizome with a light-brown external surface shows longitudinal striations and occasional loose fibres; the outer surface of the unscraped rhizome varies from pale to dark brown and is more or less covered with cork that shows conspicuous, narrow, longitudinal and transverse ridges; the cork readily exfoliates from the lateral surfaces but persists between the branches. The fracture is short and starchy with projecting fibres. The smoothed transversely cut surface exhibits a narrow cortex separated by an endodermis from a much wider stele; it shows numerous, scattered, fibrovascular bundles and abundant scattered oleoresin cells with yellow contents. The unscraped rhizome shows, in addition, an outer layer of dark brown cork.
B.Reduce to a powder (355) (2.9.12). The powder is pale yellow or brownish. Examine under a microscope using chloral hydrate solutionR. The powder shows the following diagnostic characters (Figure 1522.-1): groups of large, thin-walled, septate fibres, with one wall frequently dentate[C, D, G]; fragments[K] containing vessels with reticulate thickening[Ka] often accompanied by narrow, thin-walled cells containing brown pigment[Kb] and amyliferous parenchyma[Kc]; abundant reticulate vessels, fairly large, isolated[H, L]; abundant thin-walled parenchyma of the ground tissue[J,M], some cells containing brown oleoresin[Ja]; fragments of brown cork, usually seen in surface view[F] but sometimes in transverse section[E]. Examine under a microscope using a 50per centV/V solution of glycerolR. The powder shows abundant starch granules, simple, flattened, oblong or oval or irregular, up to about 50µm long and 25µm wide, with a small point hilum situated at the narrower end; sometimes, granules show faint, transverse striations, and may be free[A], agglomerated[B] or included in parenchymatous cells(Kc).
C.Thin-layer chromatography (2.2.27).
Test solution. To 1.0g of the powdered herbal drug (710) (2.9.12) add 5mL of methanolR. Shake for 15min and filter.
Reference solution. Dissolve 10µL of citralR and 10mg of resorcinolR in 10mL of methanolR. Prepare the solution immediately before use.
Plate: TLC silica gel plateR.
Mobile phase: hexaneR, etherR (40:60V/V).
Application: 20µL as bands.
Development: in an unsaturated tank, over a path of 15cm.
Drying: in air.
Detection: spray with a 10g/L solution of vanillinR in sulfuric acidR and examine in daylight while heating at 100-105°C for 10min.
Results: the chromatogram obtained with the reference solution shows in the lower half an intense red zone (resorcinol) and in the upper half 2 violet zones (citral); the chromatogram obtained with the test solution shows below the zone due to resorcinol in the chromatogram obtained with the reference solution 2 intense violet zones (gingerols) and in the middle, between the zones due to resorcinol and citral in the chromatogram obtained with the reference solution, 2 other less intense violet zones (shogaols); other zones may be present.
Figure 1522.-1. – Illustration for identification testB of powdered herbal drug of ginger
Rhubarb
Rhei radix
DEFINITION
Rhubarb consists of the whole or cut, dried underground parts of Rheum palmatumL. or of Rheum officinale Baillon or of hybrids of these two species or of a mixture. The underground parts are often divided; the stem and most of the bark with the rootlets are removed. It contains not less than 2.2per cent of hydroxyanthracene derivatives, expressed as rhein (C15H8O6, Mr284.2), calculated with reference to the dried drug.
CHARACTERS
Characteristic, aromatic odour.
IDENTIFICATION
A. The appearance is variable: disc-shaped pieces up to 10cm in diameter and 1cm to 5cm in thickness; cylindrical pieces; oval or planoconvex pieces. The surface has a pinkish tinge and is usually covered with a layer of brownish-yellow powder. It shows, especially after moistening, a reticulum of darker lines. This structure causes the marbled appearance of the drug. The fracture is granular. The transverse section of the rhizome shows a narrow outer zone of radiating brownish-red lines. These medullary rays are crossed perpendicularly by a dark cambial ring. Inside this zone is a ring of small star-spot formations of anomalous vascular bundles. The root shows a more radiate structure.
B. Reduce to a powder (355) (2.9.12). The powder is orange to brownish-yellow. Examine under a microscope using chloral hydrate solutionR. The powder shows the following diagnostic characters: large calcium oxalate cluster crystals, which may measure more than 100µm, and their fragments; reticulately thickened non-lignified vessels measuring up to 175µm. Numerous groups of rounded or polygonal, thin-walled parenchyma cells. Sclereids and fibres are absent. Examine under a microscope using a 50per centV/V solution of glycerolR. The powder shows simple, rounded or compound (2 to 4) starch granules with a star-shaped hilum.
C.Examine by thin-layer chromatography (2.2.27), using a suitable silica gel as the coating substance.
Test solution. Heat 50mg of the powdered herbal drug (180) (2.9.12) in a water-bath for 15min with a mixture of 1mL of hydrochloric acidR and 30mL of waterR. Allow to cool and shake the liquid with 25mL of etherR. Dry the ether layer over anhydrous sodium sulfateR and filter. Evaporate the ether layer to dryness and dissolve the residue in 0.5mL of etherR.