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       Alexandrian Senna Leaf is the dried leaflets of Senna alexandriana Mill. var. alexandriana
(Cassia acutifolia Delile, Cassia angustifolia Vahl) (Family Leguminosae), Herbarium
Specimen Number: DMSC 5366, Crude Drug Number: DMSc 1241.
Constituents Alexandrian Senna Leaf contains hydroxyanthracenes and its glycosides (e.g.,
aloe-emodin, sennosides A and B). It also contains flavonoids, sterols, etc.
Description of the plant (Fig. 1) Perennial herb 0.5 to 1.5 m tall; stem erect, glabrous,
sparsely pubescent or strigulose. Leaves paripinnately compound, alternate; petiole up to
5 cm long; stipule subulate to lanceolate; leaflets 3- to 8-paired, elliptic to lanceolate, 2.5 to
5 cm long, 1 to 1.5 cm wide, apex acute to obtuse, base oblique, margin entire, pubescent on
both surfaces. Inflorescence racemose, terminal or axillary, up to 15 cm long; bract obovate,
7 to 8 mm long. Flower yellow; sepals 5, obovate, 1 to 1.3 cm long, 6 to 8 mm wide; petals 5,
bright yellow with distinct veins, obovate, 1 to 1.7 cm long, 0.7 to 1 cm wide, shortly clawed;
stamens 10, upper 3 reduced to staminodes, 7 perfect with 2 lower largest; ovary superior,
densely hairy, stipitate. Fruit a dehiscent pod, oblong to broadly elliptic or reniform, 4 to
7 cm long, about 2 cm wide, green when young, becoming brownish when mature, flattened.
Seeds 4 to 10; stipe 2 to 3 mm long.
Description Odour, faint, characteristic; taste, mucilaginous, slightly bitter.
     Macroscopical (Fig. 1) Green to brownish green leaflet, entire or broken; entire leaf elongated,
lanceolate, 1.5 to 5 cm long, 0.5 to 2 cm wide, apex acute to obtuse, base oblique, blade thin,
sometimes marked with transverse or oblique lines, abaxial surface with visible pinnate
vernation, margin with anastomosing lateral veins, both surfaces pubescent.
      Microscopical (Figs. 2a‒2c) Transverse section of the leaflet through the midrib shows
upper epidermis, mesophyll, vascular tissue, and lower epidermis. Upper epidermis: cuticle
layer, 1 to 2 layers of rectangular cells and thin-walled cells (some containing mucilage),
slightly sunken stomata, and warty-walled unicellular trichomes. Mesophyll: unifacial,
a layer of cylindrical palisade cells, parenchyma, some of which containing rosette aggregate
or prismatic crystals, and angular collenchyma in the midrib. Vascular tissue: collateral bundle,
surrounded with fibres and prismatic sheath; and parenchyma, some containing rosette
aggregate crystals. Lower epidermis: cuticle layer, 1 to 2 layers of rectangular cells, slightly
sunken stomata, and warty-walled unicellular trichomes.
     In surface view, the lamina shows upper epidermis and lower epidermis. Both epidermises:
polygonal shaped, warty-walled unicellular trichomes; stomata, mostly paracytic, some
anomocytic and anisocytic, and cicatrices; some containing mucilage.
Alexandrian Senna Leaf in powder possesses the diagnostic microscopical characters of
the unground drug. Warty-walled unicellular trichomes, epidermal cells containing
mucilaginous substance, fibres with prismatic sheath, and mesophyll with abundant prismatic
and rosette aggregate crystals are characteristic.

Packaging and storage Alexandrian Senna Leaf shall be kept in well-closed containers,
protected from light, and stored in a dry place.
Identification
     A. To 1 g of the sample, in powder, add 30 mL of 0.5 M potassium hydroxide and 2 mL
of a 3 per cent v/v solution of hydrogen peroxide, and heat on a water-bath for 10 minutes.
Allow to cool and filter. Acidify the filtrate with sufficient amount of glacial acetic acid and
then shake with 20 mL of dichloromethane. Separate the dichloromethane layer and mix well
with 2 mL of ammonia TS: the aqueous layer becomes pinkish red.
     B. Carry out the test as described in the “Thin-Layer Chromatography” (Appendix 3.1),
using silica gel F254 as the coating substance and a mixture of 40 volumes of ethyl acetate,
40 volumes of propanol, 30 volumes of water, and 1 volume of glacial acetic acid as the mobile
phase and allowing the solvent front to ascend 8 cm above the line of application. Apply to
the plate as bands of 6 mm, 2 μL of solution (A), 1 μL each of solutions (B) and (D), and 7 μL
of solution (C). Prepare solution (A) by sonicating 500 mg of the sample, in No. 250 powder,
with 5 mL of a mixture of equal volumes of ethanol and water for 10 minutes. Centrifuge the
resulting solution at 2683 × g (4000 rpm) for 5 minutes and use the supernatant. For
solution (B), dissolve 5 mg of sennoside B in 1 mL of methanol. For solution (C), dissolve 5 mg
of sennoside A in 1 mL of methanol. For solution (D), dissolve 5 mg of rhein in 1 mL of methanol.
After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm),
marking the quenching bands. The chromatogram obtained from solution (A) shows three
quenching bands (hR_f values 31 to 35, 50 to 54, and 88 to 92) corresponding to sennoside B,
sennoside A, and rhein from solutions (B), (C), and (D), respectively. Spray the plate with
a 5 per cent w/v solution of potassium hydroxide in methanol and heat at 110º for 10 minutes.
Immediately examine the plate under ultraviolet light (366 nm); the bands due to sennoside B,
sennoside A, and rhein are orange-brown, yellow, and pink-brown fluorescent, respectively.
Other two pink fluorescent bands are also observed (Fig. 3).
Loss on drying Not more than 8.0 per cent w/w after drying at 105º to constant weight
(Appendix 4.15).
Foreign matter Not more than 2.0 per cent w/w (Appendix 7.2).
Acid-insoluble ash Not more than 1.0 per cent w/w (Appendix 7.6).
Total ash Not more than 12.0 per cent w/w (Appendix 7.7).
Content of hydroxyanthracene glycosides Not less than 1.8 per cent w/w of
hydroxyanthracene glycosides, calculated as sennoside B (C₄₂H₃₈O₂₀) when determined by
the following method. (Note Carry out the determination protected from light.)
Sample preparation Place 150 mg of Alexandrian Senna Leaf, in fine powder, accurately
weighed, in a 100-mL round-bottomed flask. Add 30.0 mL of water, mix, weigh, and place
in a water-bath. Heat under a reflux condenser for 15 minutes. Allow to cool, weigh, and
adjust to the original weight with water. Centrifuge the resulting solution at 2683 × g (4000 rpm)
for 5 minutes and transfer 20.0 mL of the supernatant liquid to a 150-mL separator. Add
0.1 mL of dilute hydrochloric acid and shake with three 15-mL portions of chloroform. Allow
to separate and discard the chloroform layer. Add 100 mg of sodium hydrogen carbonate and
shake for 3 minutes. Centrifuge and transfer 10.0 mL of the supernatant liquid to a 100 mL
round-bottomed flask with a ground-glass neck. Add 20 mL of iron(III) chloride TS and mix.
Place the flask in a water-bath so that the water level is above that of the liquid in the flask,
and heat under a reflux condenser for 20 minutes. Add 3 mL of hydrochloric acid and heat for

a further 20 minutes, with frequent shaking, to dissolve the precipitate. Cool, transfer the
mixture to a separator, and shake with three 25-mL portions of ether previously used to rinse
the flask. Combine the three ether layers and wash with two 15-mL portions of 15 mL of
water. Transfer the combined ether layers to a volumetric flask and dilute to 100.0 mL with
ether. Evaporate 10.0 mL carefully to dryness and dissolve the residue in 10.0 mL of a 0.5 per
cent w/v solution of magnesium acetate in methanol.
     Procedure Measure the absorbance of Sample preparation at 515 nm using methanol as the
blank.
     Calculation Calculate the percentage content of hydroxyanthracene glycosides, calculated
as sennoside B, in the portion of Alexandrian Senna Leaf taken, utilizing the specific absorbance
of sennoside B to be 240, by the expression:
                                                        1.25x A/W,
where A is the absorbance of the sample at 515 nm and W is the weight, in g, of the
Alexandrian Senna Leaf taken.