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          Senna Garrettiana Heartwood is the dried heartwood of Senna garrettiana (Craib) H. S. Irwin & Barneby (Cassia garrettiana Craib) (Family Leguminosae-Caesalpinioideae), Herbarium Specimen Number: DMSC 5225, Crude Drug Number: DMSc 1098.

Constituents Senna Garrettiana Heartwood contains anthraquinones (e.g., aloe-emodin, cassialoin, chrysophanol, emodin) and stilbenes (e.g., cassigarols, piceatannol).

Description of the plant (Fig. 1) Tree up to 10 m tall; bark greyish black, cracked. Leaves even-pinnate, alternate; rachis 10 to 20 cm long; petiole 4 to 5 cm long; stipule early caducous; leaflets 6 to 9 pairs, lanceolate to broadly ovate, 5 to 9 cm long, 2 to 5 cm wide, apex acuminate, base rounded, margin entire, glabrous to pubescent; petiolule 4 to 6 mm long. Inflorescence compound raceme, terminal, 9 to 20 cm long; bract ovate, about 4 mm long, apex acute, caducous; bracteole minute. Flower bright yellow; pedicel 2.5 to 4 cm long; sepals 5, unequal, 2 outer smaller, about 5 mm long, 3 inner twice as long, broadly elliptic, puberulous outside; petals 5, obovate or obovate-elliptic, 1 to 1.8 cm long, 0.8 to 1.2 cm wide, with claw, about 4 mm long; stamens 10, 2 longest with flattened filaments, 7 to 8 mm long, anther 7 to 9 mm long, curved, opening by apical pores, 5 shorter with smaller anthers, and 3 stamens reduced, about 3 mm long; ovary superior, glabrous or puberulous, style short, stigma indistinct. Fruit pod, flattened, 15 to 22 cm long, 2 to 4 cm wide, often slightly twisted, glabrous or puberulous; stalk 3 to 5 cm long. Seed ovoid or oblong-ovoid, 6 to 9 mm long, about 5 mm wide, brownish.

Description Odour, mild; taste, bland.
       Macroscopical (Fig. 1) Longitudinally sliced heartwood, rough, dense, hard, reddish brown to dark-brown.
       Microscopical (Figs. 2a, 2b, 2c, 2d) Transverse section of the heartwood shows a diffused-porous wood type consisting of vessels, axial parenchyma, xylem rays, and fibres. Vessel, large, solitary or in cluster of 2 to 4, scattered, some containing brown substance. Axial parenchyma, paratracheal type, slightly thick-walled cells, some containing brown substance. Xylem ray, 1 to 2 layers, rectangular cells, some containing brown substance. Fibre, thick-walled cells, some containing brown substance. Radial and tangential longitudinal sections of the heartwood show vessels, axial parenchyma, xylem ray, and fibres. Vessel, large cylindrical, bordered-pitted, some containing brown substance. Axial parenchyma, rectangular, slightly thick-walled cells, some containing brown substance. Xylem ray: homocellular type, rectangular, porous, slightly thick-walled cells, some containing brown substance or prismatic crystals, in radial longitudinal view; uniseriate rays and mostly biseriate rays, in tangential longitudinal view. Fibre, thick-walled cells, some containing brown substance. Senna Garrettiana Heartwood in powder possesses the diagnostic microscopical characters of the unground drug. Groups of fibres, some containing brown substance are unique. Large bordered-pitted vessels may also be observed. 

Packaging and storage Senna Garrettiana Heartwood 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 fine powder, add 10 mL of dichloromethane, warm on a water-bath for 5 minutes and filter. To 1 mL of the filtrate, add 1 mL of a 10 per cent w/v solution of potassium hydroxide: the aqueous layer becomes red.
       B. Reflux 1 g of the sample, in fine powder, with 20 mL of ethanol for 15 minutes and filter. To 2 mL of the filtrate, add a few drops of iron(III) chloride TS: a dark blue colour is produced.
       C. 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 60 volumes of toluene, 40 volumes of ethyl acetate and 5 volumes of formic acid as the mobile phase and allowing the solvent front to ascend 10 cm above the line of application. Apply separately to the plate as bands of 8 mm, 5 µL each of the following solutions. Prepare solution (A) by refluxing 1 g of the sample, in fine powder, with 10 mL of ethanol for 10 minutes and filtering. Evaporate the filtrate to dryness and dissolve the residue in 2 mL of ethanol. For solution (B), dissolve 1 mg of piceatannol in 1 mL of ethanol. After removal of the plate, allow it to dry in air and examine the plate under ultraviolet light (254 nm), marking the quenching bands. The chromatogram obtained from solution (A) shows a quenching band (hRf value 48 to 51) corresponding to the piceatannol band from solution (B); other quenching bands are also observed. Subsequently examine the plate under ultraviolet light (366 nm) through the cut-off filter, the band corresponding to piceatannol shows blue fluorescence. Several other fluorescent bands of different colours are also observed. Spray the plate with anisaldehyde TS and heat at 105° for 5 minutes; the band due to piceatannol is purple. Several other bands of different colours are observed. (Table 1); see also Fig. 3.

Table 1 hR_f Values of Components in Ethanolic Extract of the Heartwood of Senna garrettiana (Craib) H. S. Irwin & Barneby

       *piceatannol

Loss on drying Not more than 8.0 per cent w/w after drying at 105° to constant weight (Appendix 4.15).

Foreign matter Not more than 2.0 per cent w/w (Appendix 7.2).

Total ash Not more than 9.0 per cent w/w (Appendix 7.7).

Ethanol-soluble extractive Not less than 6.0 per cent w/w (Appendix 7.12).

Water-soluble extractive Not less than 3.0 per cent w/w (Appendix 7.12).