عنوان المقالة:تقييم الخصائص الكيميائية والبيولوجية لأزهار نبات الألبيسيا لبخ النامي في المملكة العربية السعودية Evaluation of the Phytochemical and Biological Properties of Albizia lebbeck Flowers Growing in Saudi Arabia
Albizia lebbeck L. ( الألبيزيا لبخ ( is a member of the legume family (Fabaceae) which
is the third largest family of flowering plants with more than 18,000 described species. A.
lebbeck L. is among the most important tree species imported many years ago from India
and well adapted to the harsh environmental conditions of the central part of Saudi
Arabia. It is used for furniture, flooring and a variety of agricultural tools. The cut bark
yields a reddish-brown gum used as a substitute for gum Arabic obtained from Acacia
senegal. A. lebbeck L. has many synonyms such as Acacia, koko, shack-shack, whistlingbean,
Sarenh and woman’s tongue.
The current literature revealed that some plants belonging to the genus Albizia
have possessed medicinal values. Previous phytochemical investigation of different
species belonging to genus Albizia afforded different classes of secondary metabolites
such as saponins, terpens, alkaloids and flavonoids. Some bioactive compounds were
isolated and identified from genus Albizia e.g. triterpenoid saponins (julibroside J29,
julibroside J30, julibroside J31) , novel macrocyclic alkaloids (budmunchiamines A, B and
C) and two flavonol glycosides (quercitrin and isoquercitrin) which showed different
biological activities such as anti-tumor, antiplatelets aggregation and bactericidal
activities.
Reviewing the current literature for the importance of the plant Albizia lebbeck
growing worldwide revealed many biological interests, but nothing was reported
concerning the species cultivated in Saudi Arabia. This study was dedicated to the
biological investigations of some phytochemical metabolites in A. lebbeck. Preliminary
biological evaluation of different extracts of the titled species has been performed and
revealed the presence of secondary metabolites exhibiting antibacterial, estrogenic, anti -
inflammatory, analgesic and antipyretic activities.
The phytochemical investigation of A. lebbeck cultivated in Saudi Arabia resulted
in isolation and identification of one novel β- lactam derivative; albactam, in addition to
seven knwon compounds; β- Amyrin, 11α, 12α-oxidotaraxerol, 1-O-β-D-glucopyranosyl-
[(2S, 3S, 4R, 8E)-2-[(2-R)-hydroxyhexadecanoylamino]-8-tetra-cosene-1, 3, 4-triol, [(2S,
II
3S, 4R, 8E)-2-[(2’R)-hydroxyhexadecanoylamino]-8-tetra-cosene-1, 3, 4-triol, 3, 7-
dimethyloct-1-en-3, 6, 7-triol, rutin and kaempferol-3-O-rutinoside. 11α, 12α-
oxidotaraxerol, 3, 7-dimethyloct-1-en-3, 6, 7-triol, ceramide and its glycoside are
reported for the first time from the species lebbeck.
The new compound, albactam, was subjected to further biological evaluation and
it showed anti-aggregatory activity against adenosine diphosphate and arachidonic acidinduced
guinea-pigs' platelets aggregation in vitro at doses 208 μg/ml and 172 μg/ml
respectively, whereas yields of other compounds were low.
Therefore, this study is represented in five parts:
- Part 1: The introductory part that includes a review of taxonomic
classification of Albizia lebbeck, folkloric uses and biological activities.
Furthermore, the isolation of chemical constituents from A. lebbeck are
covered in this part.
- Part 2: Materials and methods that includes all materials, equipments and
techniques used in this study. In addition, the details of the biological
evaluation methods, isolation and characterization of isolates are covered.
Moreover, detailed preliminary phytochemical screening tests are also
presented.
- Part 3: Results and discussion includes characterization and structure
elucidations of the isolated compounds are listed.
- Part 4: Detailed biological screening results for antimicrobial, antipyretic,
analgesic, estrogenic and anti-inflammatory activities are presented in the
biological investigation part.
- Part 5: Includes a list of references found at the end of this thesis.
محمد فرج عبد الحليم عبد الله | Mohamed Farag Abd El Halim Abd Alla | 5385