| Abstract: |
Tarchonanthus camphoratus L. (Compositae) is a large shrub, it attains a height of 5 meters. It shows monopodial branching. The plant grows in the steep rocky slopes, 1600-1800 m above sea level. It prefers sandy soil and climate of moderate humidity.By reviewing the available current literature, nothing could be traced about the plant including its active constituents, so this stimulated the following work:Part I : Botanical study; including :the macro- and micromorphology of the different organs of the plant viz. leaves, stems, male and female capitulum, and finally the fruit in addition to their powdered forms.Part II : Phytochemical study ; including : phytochemical screening , extraction, fractionation, isolation and identification of the different constituents of the dried aerial parts.Part III : Investigation of some pharmacological effects of the ethanolic extract of Tarchonanthus camphoratus L. including:1. Analgesic and anti-inflammatory effects.2. Anti-convulsant effect.PART IBotanical study of Tarchonanthus camphoratus L.Chapter IMacromorphology of Tarchonanthus camphoratus L. :Tarchonanthus camphoratus L. is a large shrub with a strong camphoraceous odour.It attains a height of 5 meters.It shows monopodial branching and carries alternate,petioled,coriaceous leaves.The plant is dioecious.It prefers sandy soil and climate of moderate humidity.1. Macromorphology of the Leaf :The leaves are alternate petioled and coriaceous.Each leaf is about 8-15 cm long and 1.5-4 cm wide.Its shape is lanceolate-oblong or ovate,acute at the base,subacute or obtuse at the apex,quite entire or denticulate, camphoraceous odour and a very bitter taste.2. Macromorphology of the Stem :The main trunk of the plant is erect,cylindrical in shape and solid.It is usually fairly a tall shrub but can grow to 5 meters tree.3. Macromorphology of the Capitulum :i.Male capitulum:It is globose to hemispherical in shape about 0.8-1.2 cm in diameter. The involucre is uniseriate, united at the lower half while free from above. It is ovate in shape, tomentose outside while glabrous from inside.The receptacle is flat to nearly concave bearing very dense silky hairs.ii. Female capitulum :It is globose to hemispheric-conical , about 5 mm in diameter. The involucre is biseriate where the involucral bracts are free , tomentose outside and glabrous inside. The outer ones are ovate in shape while the inner ones are ovate-oblong. The receptacle is more or less concave bearing very dense silky hairs.4. Macromorphology of the Fruit :The fruit is obovate-oblong, compressed and very wooly.CHAPTER IIMICROMORPHOLOGY OF TARCHONANTHUS CAMPHORATUS L.1. Micromorphology of the Leaf :The upper epidermis :It consists of one layer of radially elongated cells having straight beaded anticlinal walls and covered with very thick but smooth cuticle. Stomata are found sunken with hairs.Hairs of non-glandular type are found, which are long uniseriate, unicellular or multicellular, covered with smooth cuticle, having wide lumen and acute apex.The lower epidermis :Similar to those of the upper epidermis with the cells slightly smaller than those of the upper epidermis.Stomata are sunken with a thick layer of hairs.Hairs present are the same as those found on the upper epidermis in addition to short glandular hairs having bicellular head and multicellular stalk.The mesophyll :It is of dorsiventral type, consists of palisade and spongy tissues. The upper palisade cells are arranged in 2 layers abaxially and beneath are present the spongy parenchyma arranged also in 2 layers abaxially.The cortical tissue :It is represents a wide zone surrounding the vascular bundles. There are an upper and a lower subepidermal collenchymatous masses. Both are being thin-walled, more or less isodiametric rows with small intercellular spaces.The vascular system :It is represented by about 5 normal vascular bundles of the midrib and few smaller ones on each side representing the veins. The bundle is collateral and formed of an upper arc of radiating xylem and a lower patch of phloem.The xylem:The xylem consists of lignified mostly spiral, sometimes pitted and annular vessels. The vessels are separated by thin-walled cellulosic wood parenchyma.The phloem:The phloem is wide and consists of cellulosic thin walled sieve elements.The pericycle:The pericyclic fibers represent 2-3 rows constituting the pericycle, each fiber thin lignified with a narrow lumen and rounded to tapering apex. Wood fibers are present which have wide lumen, rounded apices in addition to lignified walls.2. Micromorphology of the Petiole :The epidermis :It is formed of one layer of radially elongated cells as seen in T.S. having straight beaded anticlinal walls covered with very thick and smooth cuticle. Each cell bears a long hair identical to that found on the leaf surface. Stomata are found very rare sunken with a thick layer of non-glandular hairs.The ground tissue :It consists of of cartilagenous collenchyma forming about 4 rows following polygonal parenchyma with moderately small intercellular cells.The vascular system:The pericycle :It consists of a continuous lower arc of lignified pericyclic fibres with thick, lignified, sometimes pitted wall with narrow lumen and rounded apex.The phloem :It consists of a relatively wide zone.It is formed of thin walled sieve elements.The cambium :It is seen clearly consisting of tangentially elongated, radially arranged, thin walled meristematic cells.The xylem :It consists of lignified vessels with mainly spiral, pitted and rarely annular thickening. The vessels are separated by lignified tracheids and tracheidal vessels with lignified pitted walls.3. Micromorphology of the Stem :The epidermis :It is formed of one row of radially elongated cells, each bearing a unicellular or multicellular, thin walled, long, non-glandular hair. The cells have straight, slightly beaded anticlinal walls, covered with smooth cuticle.The cortex :It consists of 3 outer layers of collenchyma followed internally by 5-6 layers parenchyma being thin walled with narrow intercellular spaces.The vascular system:The pericycle :It is composed of 5-6 rows of fibers which are more or less continuous. The fibers have thick lignified walls, narrow lumens and acute apices.The phloem :It constitutes a markedly narrow zone. It is composed of sieve elements with cellulosic thin walls.The cambium :It is seen as a clear zone of about 2-5 rows of thin walled meristimatic cells which are subrectangular tangentially elongated and radially arranged.The xylem :It is formed of lignified vessels with mainly annular and pitted thickening.The pith :It is solid, wide and composed of large thin walled hexagonal to polygonal parenchyma with small intercellular spaces.4. Micromorphology of the peduncle:The epidermis:It is one row of radially elongated cells, each bearing a simple non-glandular hair, covered with smooth cuticle.The cortex:It consists of several rows of collenchyma followed internally by parenchymatous cells. Both cells are free of any contents.The pericycle:It is formed of continuous layer of sclerenchyma composed pericyclic fibres having thick lignified walls, narrow lumens and rounded apices.The phloem:It constitutes a narrow zone and formed of sieve elements.The cambium:It consists of several rows of thin walled meristimatic cells.The xylem:It is formed of lignified vessels with mainly annular and spiral thickening. The vessels are separated by tracheids and tracheidal vessels. Wood fibres are also seen having lignified walls, wide lumen and acute apices.The pith:It is solid narrow and composed of thin walled parenchymatous cells.5. Micromorphology of the involucral bract:The inner (upper)epidermis:It consists of one layer of radially elongated cells with no hairs or glands.The outer (lower) epidermis:It consists of one layer of radially elongated cells with non-glandular hairs similar to those found on the stem surface.The mesophyll:It consists of collenchyma followed by parenchymatous cells of small intercellular spaces.The Vascular system:It is represented by 3 vascular bundles, each is collateral formed of an inner radiating xylem and a lower patch of phloem.6. Micromorphology of the fruit (achene):The epidermis:It is composed of radially elongated cells each bearing a long hair identical to that found on the stem surface. Stomata are very rarely present.The pericarp:It is narrow, formed of parenchyma followed by a continuous layer of sclerenchyma.The testa:It consists of one layer of cells which have a very characteristic U-shaped thick thickening.7. Pollen grain morphology :It is isopolar, radially symmetrical, subprolate-prolate , broadly elliptic with broad ends in the equatorial view, rounded, triangular in polar view, 3-colporate , exine with blunt spinules.PART IIPhytochemical Study of Tarchonanthus camphoratus L.CHAPTER IPreliminary Phytochemical Screening of the Powdered Aerial PartsThe preliminary phytochemical screening of the air-dried powdered aerial parts revealed:1-The powdered air-dried aerial parts contain: carbohydrates and/or glycosides, volatile substances, alkaloids and/or basic nitrogenous substances, unsaturated sterols and/or triterpenes, flavonoids and lactones and/or esters.2-The powdered air-dried aerial parts don’t contain any crystalline sublimates, cardenolides, saponins, oxidase enzyme, cyanogenetic glycosides anthraquinones, coumarins and iridoids.CHAPTER IIExtraction, Fractionation and Isolation of the Constituents of the Powdered Aerial Parts Of Tarchonanthus camphoratus L.1-Extraction and Fractionation:The air-dried aerial parts (2Kg) were percolated successively with chloroform and 70% ethanol. The chloroformic and ethanolic extracts were concentrated under reduced pressure to give 150 and 40g residue respectively.2- Isolation of the Main Constituents of the Chloroformic Fraction of the Aerial Parts of Tarchonanthus camphoratus L.:a. Thin layer Chromatographic Screening :The chloroformic fraction was subjected to TLC screening using silica gel GF254 plates as adsorbent and systems I, II, III and IV as developers. The chromatograms of the chloroform fraction revealed the presence of at least 10 spots some of them were identified as α-amyrin, β-sitosterol, β-sitosterol glucoside, apigenin and luteolin which were identified by direct authentication, Rf values and co-chromatography.b. Column Chromatographic Fractionation of the Chloroform Fraction :The chloroformic fraction of the aerial parts of Tarchonanthus camphoratus L. was chromatographed over silica gel column and eluted with n-hexane and ethyl acetate in gradient elution to isolate all the contained compounds.3-Isolation of the Main Constituents of the Ethanolic Fraction of the Aerial Parts of Tarchonanthus camphoratus L.:a. Thin layer Chromatographic Screening :The ethanolic aqueous fraction was subjected to TLC screening using silica gel GF254 plates as adsorbent and systems IV and V as developers. The chromatograms of the ethanolic aqueous fraction revealed the presence of several spots some of them were identified while the rest were left for further study.b. Column Chromatographic Fractionation of the Ethanolic Aqueous Fraction :The ethanolic aqueous fraction of the aerial parts of Tarchonanthus camphoratus L. was chromatographed over silica gel column and eluted with chloroform and methanol in gradient elution to isolate some of the contained compounds.Chapter IIIStructure elucidation of the Isolated CompoundsThe structure elucidation of the isolated compounds was deduced on the basis of spectroscopic methods (IR, UV, ¹H-NMR, ¹³C-NMR and MS) in addition to comparison of the physical, chemical and chromatographic characters of these compounds with those of the available authentic samples. A list of the identified compounds was recorded in Table (23).Table(23): A list of the isolated compounds from Tarchonanthus camphoratus L.But upon publication of USP 30; dissolution parameters have been changed from 1000 ml water at 100 r.p.m for 60 minutes to 900 ml water at 75 r.p.m for 45 minutes. The conforming clonazepam 2 mg tablets according to USP 27 have been re-analyzed according to USP 30 dissolution parameters. It was found that these tablets are not conforming to specifications of USP 30. Therefore; many trials with different ideas have been recently done in order to produce tablets conforming to dissolution specifications.Wet granulation technique using polyethylene glycol 6000 (1 gm) dissolved in acetone (either 50 ml or 100 ml) has also been done where the ratio of clonazepam: PEG 6000 was 1:1.Different clonazepam: PEG 6000 ratios 1:2, 1:3, 1:5, 1:7 and 1: 9 have been used by dissolving clonazepam and PEG 6000 in acetone 33 ml and have been incorporated into tablets.
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