الفهرس 
Part 1 : Phytochemical and biological investigation of Tabebuia aurea leaves
Chapter I: Preliminary phytochemical screening of the powdered leaves of T.Only 14 pages are availabe for public view
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Abstract
Bignoniaceae is a large family of flowering plants comprises around 110 genera and 650 species. Tabebuia is the most important genus of Bignoniaceae including about 100 species distributed in tropical and subtropical regions around the world. T. aurea is considered an important remarkable species for the local population of the Brazilian Cerrado and traditionally used as anti-inflammatory and for snake bites.
In this study, we performed phytochemical and biological studies of T. aurea leaves as follows:
Chapter I
Preliminary phytochemical screening of the powdered leaves of T. aurea.
T. aurea leaves contained carbohydrates and/or glycosides, unsaturated sterols and/or triterpenes, flavonoids and tannins. It is free from crystalline sublimate substances, nitrogenous compounds and/or alkaloids, saponins, anthraquinones, cardiac glycosides and coumarins.
Chapter II
Extraction, fractionation and isolation of the constituents from the leaves of T. aurea.
The air-dried powdered (1.8 kg) of T. aurea leaves were extracted by maceration with (95% EtOH) till exhaustion, then the ethanolic extract was concentrated under reduced pressure to give viscous residue (150 g).
The dried ethanol extract (150 g) was suspended in the least amount of distilled water and transferred to a separating funnel then fractionated with successive portions of pet. ether and EtOAc and concentrated under reduced pressure to give pet. ether and EtOAc fractions (40 mg and 35 mg, respectively). The mother liquor was kept in a refrigerator for further investigation.
Thirteen compounds were isolated from the EtOAc fraction after successive chromatographic techniques using VLC, silica gel CC, RP18 CC and HPLC.
Chapter III
Identification of the isolated compounds from T. aurea
The identification and structural elucidation of the isolated compounds was carried out by various chromatographic techniques, including 1H-NMR, 13C-NMR, DEPT, UV, IR , ESI-MS and optical rotation. In addition to comparison of the physical, chemical and chromatographic properties of the isolated compounds with those reported in the literature.
A list of the isolated compounds was recorded in Table 62.
Chapter IV
Biological investigation of T. aurea leaves
1- Evaluation of anticancer activities:
The growth-inhibitory effect of the total ethanolic extract of T. aurea leaves and its sub-fractions on A549, MCF-7 and HepG2 cell lines were assessed revealing the high potency of the ethyl acetate (EtOAc) fraction as cytotoxic agent against the three cell lines. The pure isolates obtained by chromatographic separation from these fractions were also investigated against the same cell lines. Compound 1 exhibited strong cytotoxic activity against the three different cell lines. On the other hand, Compound 3 showed potent activity against HepG2 cell line, likewise 5 exhibited potent cytotoxicity against MCF-7 cell line and compound 9 exhibited strong cytotoxicity against A549 cell line while the other compounds exerted moderate to weak cytotoxic activities towards the tested cell lines.
2- Evaluation of antileishmanial activity:
The growth-inhibitory effects of the total ethanolic extract of T. aurea leaves and its sub-fractions on the L. major promastigotes were assessed Whereas, they showed no antileishmanial activity except the EtOAc fraction that showed noticeable antileishmanial activity. The pure isolates obtained by chromatographic separation from these fractions were also investigated, whereas compounds 1 and 3 showed strong antileishmanial activity, on the opposite side the other compounds showed no antileishmanial activity.
Part II:
Phytochemical and biological studies of the red sea soft coral Litophyton arboreum, Family Nephthediae
Soft corals belonging to family Nephtheidae comprising twenty genera, and represent an important source of medicinally active metabolites. The genus Litophyton is an important member of the family Nephtheidae that distributed throughout the world mainly in the Indo-Pacific region and Red Sea. Few research studies have been carried out regarding the chemical and cytotoxic evaluations of L. arboreum
In this study, we performed phytochemical and biological studies of L. arboreum as follows:
Chapter I
Preliminary phytochemical screening of the methanolic extract L. arboreum
Litophyton arboreum contain carbohydrates and/or glycosides, unsaturated sterols and/or triterpenes and free from flavonoids, alkaloids, saponins, anthraquinones and cardenolides.
Chapter II
Investigation of Litophyton arboreum total extract by LC-HR-ESI-MS analysis
Metabolomic interpretation employing LC‐HR‐ESI‐MS was used to temporarily determine and dereplicate the secondary metabolites of L. arboreum revealed the tentative identification of several metabolites including sesquiterpenes and steroids.
Chapter III
Extraction, fractionation and isolation of the constituents from L. arboreum
The Litophyton arboreum ( ̴ 1.8 Kg wet wt.) were cut into small pieces and extracted by maceration in methanol till exhaustion. The methanolic extract was concentrated under reduced pressure at 50 ℃ to obtain a (38 g) dried residue.
The total methanolic extract was subjected to fractionation on a vacuum liquid chromatography (VLC) column packed with silica gel, yielded the corresponding n-hexane (1.0 g), n-hexane-chloroform (1:1) (9.0 g), chloroform (2.5 g), EtOAc (5.5 g), and MeOH (18.0 g) fractions.
Eleven compounds were isolated from the fraction n-hexane-chloroform (1:1) and three compounds from EtOAc fraction after successive chromatographic techniques using VLC, silica gel C.C, RP18 C.C and HPLC.
Chapter IV
Identification of the isolated compounds from L. arboreum
The identification and elucidation of the isolated compounds structure was carried out by various chromatographic techniques, 1H-NMR, 13C-NMR, DEPT, UV, IR , ESI-MS and optical rotation. In addition to comparison of the physical, chemical and chromatographic properties of the isolated compounds with those reported in the literature.
Chapter V
Biological investigation of L. arboreum
Evaluation of anticancer activities:
The growth-inhibitory effect of the total methanolic extract of L. arboreum and its sub-fractions on A549, MCF-7 and HepG2 cancer cell lines. The results of the tested extract and fractions of L. arboreum showed that n-hexane-chloroform (1:1) fraction exhibited potent cytotoxicity towards A549 cell line, followed by chloroform fraction that showed moderate cytotoxic activity. Additionally, the ethyl acetate fraction demonstrated strong cytotoxicity against MCF-7 cell line followed by n-hexane-chloroform (1:1) and chloroform fractions that showed moderate activities. Both ethyl acetate and n-hexane: chloroform (1:1) fractions exhibited moderate cytotoxicity against HepG2 cell. On the other hand, the total extract, n-hexane and methanol fractions exhibited no activity against the tested cell lines at maximum concentration used.
Accordingly, the pure isolates obtained by chromatographic separation from these fractions were also investigated against the same cell lines. Compound 8 exhibited strong cytotoxic activity against A549 and MCF-7 cell lines. Compound 3 and 7 showed potent cytotoxicity against the A549 cell line and moderate cytotoxic activities towards the MCF-7 and HepG2 cell lines. The remaining compounds showed very weak or no activity towards the tested cell lines.
According to the obtained results, it could be concluded that the cytotoxic activities of the previously mentioned fractions are attributed to their high-level contents of sesquiterpenes and steroids.
Evaluation of the anti-lieshmanial activity
The total methanolic extract and different fractions showed no antileishmanial activity comparing to the standard antileishmanial agent miltefosine while, compounds 4, 7 and 8 showed weak antileishmanial activity. on the opposite side the other compounds showed no antileishmanial activity.