Bioassays

Question 1

Chemical diversity of compounds found in

nature =

Answer 1

Important potential source of new

drugs

Question 2

Most commonly

used natural sources (land & Marine)

Answer 2

• Plants & Microorganisms

Question 3

Ethnopharmacy

Answer 3

• investigation of the use of

natural products by an ethnic group

Question 4

discovery of Cocaine ->

Answer 4

Benzocaine & Procaine (LA’s)

Question 5

Coca leaves chewed by south American

Indians for fatigue =

Answer 5

discovery of Cocaine

Question 6

Benzocaine structure

Answer 6

see slide

Question 7

Cocaine structure

Answer 7

see slide

Question 8

First four steps

Answer 8

1 General or specific search
2 Investigation scale
3 Types of Screening assay &
Procedures
4 $

Question 9

General
approach
to Isolation (9 steps)

Answer 9

1 sample from source
2 initial solvent extraction
3 extract
4 screening tests
5 fractionation if initial extract contains active consituents
6 monitor bioassays. Discard inactive fractions, keep active fraction
7 further fractionation of active fractions
8monitor bioassays. Discard inactive fractions, active compound or compounds isolated in this fraction
9 isolation and purification of individual compounds. Determination of the structure of these compounds
10

Question 10

Groups of

physicochemical properties separated during fractionation (5 groups)

Answer 10

1 Solubility
2 Size
3 Electrical charge
4 Acidic
5 Basic

Question 11

6 Separation

methods

Answer 11

1 Solvent extraction
2 Dialysis
3 Distillation
4 Precipitation
5 Electrophoretic
6 chromatographic

Question 12

6 steps after Isolation

Answer 12

1 Purification
2 Structure
3 Commercial Interest
4 Synthesised
5 Evaluated
6 Analogues
• SAR
• QSAR

Question 13

Vincristine structure

Answer 13

see slide

Question 14

Vincristine also known as

Answer 14

leurocristine

Question 15

Vincristine marketed as brand name

Answer 15

Oncovin

Question 16

Vincristineis a chemotherapy medication used to treat (4 examples)

Answer 16

1 leukemia
2 Hodgkin’s disease
3 neuroblastoma
4 small cell lung cancer

Question 17

4 examples of structural analytical techniques

Answer 17

1 NMR
2 MS
3 IR
4 UV

Question 18

5 examples of coupled structural analytical techniques

Answer 18

1 GC-MS
2 LC-UV
3 LC-MS
4 LC-NMR
5 LC-DAD

Question 19

Dereplication can involve what 4 analytical techniques

Answer 19

1 Chromatography
2 NMR
3 UV-Vis spec
4 MS

Question 20

The American Cancer

Institute for HIV screened how many natural products and what activity resulted

Answer 20

40,000 with 15%

Question 21

4 ways activity change occurs
due to
decomposition

Answer 21

1 nature of fractionation process
2 instability of compounds
3 oxidation, hydrolysis, polymerisation
4 conditions

Question 22

Why monitoring

tests? (3 examples)

Answer 22

1 Removal of
substances with a
synergic effect on
constituents

2 Decomposition

3 Active constituent
lost in the
fractionation
process

Question 23

What should screening tests be? (8 things)

Answer 23

1 rapid
2 accurate
3 reproducable
4 high sample capacity
5 cheap
6 easy
7 useful for Tarry extracts
8 Useful for poorly soluable extracts

Question 24

Bioassays involve 3 things

Answer 24

1 screening 
2 acitivity
- environment
- time of collection
- sample prep
- storage
3 monitoring

Question 25

Taxol structure

Answer 25

see slide

Question 26

Taxol is a chemo medication used for (5 types of cancer examples)

Answer 26

``` 1 ovarian cancer 2 esophageal cancer 3 breast cancer 4 lung cancer 5 cervical cancer ```

Question 27

A bioassay is

Answer 27

an analytical method to determine concentration or potency of a substance by its effect on living cells or tissues

Question 28

Bioassays were used to

Answer 28

estimate the potency of agents by observing their effects on living organisms or tissues

Question 29

bioassays typically involve (3 aspects)

Answer 29

1 a stimulus (e.g. drugs) applied to 2 a subject (e.g. animals, tissues, plants) ``` 3 response (e.g. death) of the subject is triggered and measured. ```

Question 30

Limited and specific ivestigation involves two types of activity

Answer 30

1 Cytotoxic | 2 Antibiotic

Question 31

Wide range investigation involves what type of activity

Answer 31

many types

Question 32

limitations of investigation (2 limitations)

Answer 32

1 not sensitive enough | 2 too specific

Question 33

Classification of investigation Broad: Identifies what

Answer 33

non specific active samples

Question 34

Classification of investigation Broad: Detects what

Answer 34

many different types of activity

Question 35

4 types of tests

Answer 35

1 whole organism 2 cultured cells 3 isolated tissue 4 enzymes

Question 36

Whole organism tests involves what organisms

Answer 36

1 mircoorganisms 2 animals 3 human volunteers

Question 37

most common whole organism tests (2)

Answer 37

1 Brine shrimp lethality test (BSLT) 2 Crown gall tumour inhibition test

Question 38

Brine shrimp lethality | test obtains what values

Answer 38

LC50 or LD50 value

Question 39

Brine shrimp lethality | test is carried out over how long?

Answer 39

24 hours

Question 40

Brine shrimp lethality | test involves how many shrimp?

Answer 40

10

Question 41

Brine shrimp lethality | test involves what solution?

Answer 41

brine

Question 42

Brine shrimp lethality | test involves what type of shrimp?

Answer 42

Artemis salina

Question 43

what is the caustive agent of crown gall tumours?

Answer 43

G- Agrobacterium tumefaciens

Question 44

How thick are the potato disks in the Crown gall tumour | inhibition test?

Answer 44

0.5 cm

Question 45

Crown gall tumour | inhibition test temperature

Answer 45

room temp

Question 46

how many days later were tumours counted in the Crown gall tumour inhibition test

Answer 46

12

Question 47

what was the resulting inhibition of the Crown gall tumour | inhibition test

Answer 47

>20%

Question 48

Other whole Organism tests | Microorganisms (5)

Answer 48

``` - Bacteria •Virus •Fungi •Yeats •Amoebae ```

Question 49

Other whole Organism tests | Agar

Answer 49

* Petri dish | * 96 Well Microtitre

Question 50

Cultured cell tests are suitable for

Answer 50

HTS

Question 51

Cultured cell tests | Results - reagents

Answer 51

1 colour 2 fluorescence 3 luminescence 4 radioatctivity

Question 52

Cultured cell tests used for

Answer 52

Mammalian cell | lines

Question 53

Cultured cell tests | Receptors -Specific physiological process (2)

Answer 53

1 Binding | 2 Inihibition

Question 54

``` Isolated enzyme tests Enzyme system (2) ```

Answer 54

1 Activate | 2 Inhibit

Question 55

Isolated enzyme tests | Quantitative (2)

Answer 55

``` 1 Known amount of substrate 2 Standard quality enzyme ```

Question 56

``` Isolated enzyme tests Detectable product (4) ```

Answer 56

1 Radioactivity 2 fluorescence 3 UV and visible light absorption 4 Control

Question 57

Isolated enzyme test chemical reaction diagram

Answer 57

see slide

Question 58

isolated tissue test diagram

Answer 58

see slide

Question 59

why does activity change? (2)

Answer 59

1 due to synergy | 2 due to fractionation loss

Question 60

Dereplication Protocol by Cardellina et al.

Answer 60

see slide

Question 61

Structural Analysis of the isolated substance Ibisterol structure

Answer 61

see slide

Question 62

3 analytical ionisation techniques

Answer 62

1 Thermospray (TS or TSP) 2 Continuous-flow fast atomic bombardment (FAB) 3 Electrospray (ES)

Question 63

Mexican yams create (3)

Answer 63

``` 1 Diosgenin then 2 Cortisone then 3 Hydrocortison (cortisol) ```

Question 63

Mexican yams create (3)

Answer 63

``` 1 Diosgenin then 2 Cortisone then 3 Hydrocortison (cortisol) ```

Question 64

Mexican yams create (3)

Answer 64

``` 1 Diosgenin then 2 Cortisone then 3 Hydrocortison (cortisol) ```

Question 65

Mexican yam to cortisol reaction diagram

Answer 65

See diagram