Microscopical Transverse section of the leaf shows upper epidermis, a layer rectangular cells in Sectional view or slightly wavy-walled cells in surface view,stomata absent. Mesophyll composed of 2 to 3 layers of palisafe and several layers of spongy cells withidioblasts containing calcium oxalate prismatic crystals;fibrovascular bundle and schizolysigenous oil cavity containing oil droplets located in spongy tissues. Fibrovascular bundle composed of fibre surrounding amphicribal vascular bundle; xylem composed of spiral,reticulate,and border-pitted vessels and xylem parenchyma some of which containing prismatic crystals of calcium oxalate. Collenchyma,2 to 3 layer of cells, located in the central part of midrib beneath lower epidermis. Lower epidermis,a layer of rectangular cells in sectional view or wavy-walled cells in surface view with anomocytic type of stomata (Fig. 2a)
Citrus Hystrix Leaf in powder possesses the diagnostic microscopical characters of the unground drug(Fig.2a)
Storage Citrus Hystrix Leaf should be stored in a cool,dry place and air-dried every 2of3 months. It should be used within 1 year.
Identification
A. Reflux 1 g of the sample,in powder with30 ml of ethanol for 15 minutes,and filter.To 2 ml of the filtrate,add a few drops of ammonium molybdate TS: a yellowish green precipitate is produced.
B.To 2 ml of the filtrate obtained from test A,add a few drops of a freshly prepared 1 per cent w/v solution of iron( lll ) chloride: a deep greenish brown colour is produced.
C.extract 1 g of the sample, in powder, with 10 ml of chloroform, shake occasionally for 20 minutes,and filter. Evaporate 2 ml of the filtrate to dryness, dissolve the residue in 2 ml of acetic anhydride, and add slowly 1ml of sulfuric acid to make two layers: a brown colour forms at the zone of contact and the upper layer is green.
D.carry out the test as described in the ‘’Thin-layer Chromatography” (Appendix 3.1),using silica gel 60 F254 as the coating substance and chloroform as mobile phase bet allowing the solvent ascend 15 cm above the line of application. Apply to the plate, 10 ul of the test solution prepared by refluxing 1 g of the sample, in powder, with 30 ml of ethanol for 15 minutes, filtering, and concentrating the filtrate to 5 ml. After removal of the plate, allow it to dry in air, and examine under ultraviolet light (254 nm, 366 nm), locating the spots (Table 1); see also Fig. 3. Spray the plate with anisaldehyde TS and heat at 105 for 5 minutes. Several spots of different colours are observed (Table 1); see also Fig. 3.