Doktorarbeit / Dissertation, 2010
166 Seiten
Chapter 1 Introduction
1.1 Chrozophora hierosolymitana Spreng
1.2 Chrysanthemum leucanthemum
1.3 Ephedra gerardiana Wall. ex Stapf
1.4 Quercus dilatata
1.5 Bioassay guided fractionation:
1.6 Bioassays
1.6.1 Antimicrobial assay
1.6.2 Toxicity testing against brine shrimp
1.6.3 Potato disc antitumor assay
1.6.4 Phytotoxicity assay
1.6.5 Antioxidant assays
1.7 Phytochemicals:
1.7.1 Primary metabolites
1.7.2 Secondary metabolites
1.8 Separation and purification techniques:
Chapter 2 Biological assays of crude plant extracts
Materials and methods
2.1 Plant material
2.2 Extraction
2.3 Antibacterial assay
2.4 Antifungal assay
2.5 Toxicity testing against brine shrimp
2.6 Antitumor assay
2.7 Radish seed bioassay
2.8. DPPH radical scavenging assay
2.9 Free radical induced oxidative DNA damage analysis
2.10 Phytochemical analysis
Results
2.11 Antibacterial activity of crude plant extracts
2.12 Antifungal assay
2.13 Toxicity testing against brine shrimp
2.14 Antitumor assay
2.15 Radish seed bioassay
2.16 DPPH free radical scavenging assay
2.17 Free radical induced oxidative DNA damage analysis
2.18 Phytochemical analysis
Chapter 3 Fractionation by solvent partitioning
Materials and methods
3.1 Preparation of fractions
3.2 Antibacterial assay
3.3 DPPH radical scavenging assay
3.4 Free radical induced oxidative DNA damage analysis
3.5 Phytochemical Analysis
Results
3.6 Antibacterial activity of partitioned fractions
3.7 DPPH free radical scavenging assay
3.8 Free radical induced oxidative DNA damage analysis
3.9 Phytochemical analysis
Chapter 4 HPLC analysis of ethanol fraction
Materials and methods
4.1 HPLC analysis of ethanol fraction
4.1.1 Anaytical HPLC
4.1.2 Preparative HPLC
4.2 Antibacterial assay
4.3 DPPH radical scavenging assay
4.4 Free radical induced oxidative DNA damage analysis
4.5 Characterization of the purified active component
Results
4.6 HPLC Fractionation
4.7 Antibacterial activity of the fractions
4.8 DPPH free radical scavenging assay
4.9 Free radical induced oxidative DNA damage analysis
4.10 HPLC analysis of active fractions
4.10.1 AM2 Fraction
4.10.2 AM3 Fraction
4.11 Antibacterial activity
4.12 DPPH Free Radical Scavenging Assay
4.13 Characterization of purified active component
Chapter 5 Discussion
The primary research objective is to identify and isolate pharmacologically active components from four selected Pakistani plant species—Chrozophora hierosolymitana, Chrysanthemum leucanthemum, Ephedra gerardiana, and Quercus dilatata—by utilizing bioassay-guided fractionation to investigate their potential as chemotherapeutic agents.
1.1 Chrozophora hierosolymitana Spreng
Chrozophora hierosolymitana (Fig 1.1) is commonly known as Dyer's croton. Synonyms are Chrozophora tinctoria (L.) Raf, Chrozophora verbascifolia Baill (Nasir and Ali, 1972). Chrozophora is genus of the family Euphorbiaceae. The Euphorbiaceae (spurge family) is among the larger families of flowering plants with c. 300 genera and 8000 species (Webster, 1994). Chrozophora is sole genus comprised in the subtribe Chrozophorinae. It comprises 11 or 12 species, which are monoecious herbs or undershrubs. They are found from Africa and the Mediterranean to Southeast Asia.
Chapter 1 Introduction: Provides a comprehensive overview of the role of medicinal plants in drug discovery, the importance of traditional remedies in Pakistan, and the specific biological and chemical characteristics of the four selected plant species.
Chapter 2 Biological assays of crude plant extracts: Details the methodologies used for screening the crude extracts for antibacterial, antifungal, cytotoxic, antitumor, and antioxidant activities, including detailed procedures for each bioassay.
Chapter 3 Fractionation by solvent partitioning: Describes the process of partitioning the most active crude extract of Quercus dilatata into various solvent fractions and evaluating the biological activity of these partitioned fractions.
Chapter 4 HPLC analysis of ethanol fraction: Documents the purification of the highly active ethanol fraction from Quercus dilatata using analytical and preparative HPLC, followed by the isolation and characterization of pure active subfractions.
Chapter 5 Discussion: Integrates the research findings, discusses the observed biological activities in relation to the phytochemical profiles of the plants, and provides a conclusion regarding the identification of potentially new bioactive compounds.
Medicinal plants, Pakistan, Quercus dilatata, Bioassay-guided fractionation, Antimicrobial activity, Antioxidant activity, DPPH, HPLC, Oxidative DNA damage, Phytochemical analysis, Cytotoxicity, Antitumor, Secondary metabolites, 1,1-Diphenyl-2-picrylhydrazyl, Plasmid pBR322.
The research focuses on the screening and pharmacological evaluation of four selected plant species native to Pakistan to identify their therapeutic potential, particularly regarding antimicrobial, antitumor, and antioxidant activities.
The study examines Chrozophora hierosolymitana, Chrysanthemum leucanthemum, Ephedra gerardiana, and Quercus dilatata.
The primary goal is the isolation and characterization of pharmacologically active chemical components from these plant species using a bioassay-guided fractionation approach.
The research employs various biological assays, including antimicrobial, brine shrimp cytotoxicity, potato disc antitumor, radish seed phytotoxicity, DPPH radical scavenging, and free radical-induced oxidative DNA damage assays, followed by HPLC for purification.
The main body covers the preparation of plant extracts, a detailed biological evaluation of these extracts, the systematic fractionation of the most active candidate (Q. dilatata), and the subsequent analytical characterization of purified fractions via HPLC.
The key terms include bioassay-guided fractionation, phytochemical screening, antioxidant activity, and pharmacological screening of medicinal plants.
Quercus dilatata was selected for further study because the crude extract of its aerial parts demonstrated the most significant antibacterial and antioxidant activity during the initial screening phase.
The study suggests that the compounds successfully isolated from the Quercus dilatata ethanol fraction are chemically distinct from standard known compounds found in the same genus, indicating they could potentially be newly identified compounds.
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