Plant collection for phytochemical analysis

1. Plant Collection for Phytochemicals
Analysis
By Laiba Sarwar

2. There are many similarities between collecting plants for
herbarium making and collecting plants for phyto
chemical analysis
The major difference are in addition to making a voucher
specimen you must collect a large amount of material
from each species designated for the laboratory and that
this sample must be prepared in a way that alter as little as
possible the chemical composition of plants.

3. Selecting the locality, time of the day an population of
plants
 Criterion for selecting the species
• Do some background bibliographic research on the
species focusing on their distribution, abundance and
reproductive biology.
•Ensure that the species you have selected are abundant in
the collected sites.
•Choose large and mature plants that can better withstand
the impact of harvesting than small and immature one.
• Consider whether or not the plant population will yield a
sufficient quantity of material for analysis.

4. • Take all necessary measure to guarantee that species
can continue to produce new vegetative growth of
seeds after being harvested
• If you gather whole plant ensure that one plant
remain in each stand.
• while picking leaves from plant leave enough foliage
so that plant continue to grow and reproduce.
• on trees and shrubs harvest from side branches rather
than main trunk of branches
• Bark and roots harvested with special care.

6. •Many root like organs like rhizome, stolon, tubers, bulbs
are actually modifies stems. They often have buds for
reproduction.
• woody plants have complex root system and they can
survive if some roots are left intact.
•Individuals of same plants growing on different
localities may have striking different level of active
compounds.
•Also samples collected at different time of the day and
night and the season fluctuate in potency.

7. •Plants should not be attacked by bacteria, fungi or small
insect as they result in change in phytochemicals
composition like alkaloids and terpenoids will rise in such
cases.
•Always collect flower and fruits in voucher collection
that will help identification and keep record for future.

8. Collecting the plants
Generally for phyto-chemical analysis the bulk is collected
as dry material is needed as fresh material contain 80-90%
(leaves) or 30-40% of water in bark or stem
Preparing the plant
Once assembled the plants need to be cut into small pieces
that could be easy for handling.
Preserving the plants
Generally plants material are preserved in the laboratory by
fresh, frozen, dried, preserved or extracted in alchol.
Generally icebox is generally used.

9. •Pharmacologist accept the dried plants but generally during
drying chemical composition is effected. Effect varies from
compound to compound and objective of project
• ensure to cut plant into very small pieces to ensure uniform ad
rapid drying.
•Significance in case of drying in oven: ensure light heat and
slow drying.
•Generally het is kept below 50C.

10. •Two major Method of Drying
•Sun Drying
•Shade Drying (preferred method)
•Keep the field note book
•How plant is preserved
•Any specific env. condition
•Maturity of plants
•Time of day when collection has to made.
•Labeling the specimen
•Shipping the specimen

12. Ethics of Collecting
• Physical vouchers taken only where local population
suffers no irrevocable harm
• With rare species under investigation, essential study
materials should be removed judiciously, mitigating
damage to plant
• Required permits prior to collecting – OR authorized
personnel participate in collecting – OR authorized
personnel provide materials
• Permission from landowner or authorized personnel

13. Regulations on Collecting
•Heritage Programs (=endangered species bureaus) track rare
animals and plants
•Advisory committees of experts make biennial
recommendations to legislature for protection
• Special Concern (potentially imperiled), Threatened
(demonstrably imperiled) and Endangered (critically imperiled)
species receive attention
•Threatened and Endangered species cannot be taken on public
land without a permit
•Some states have “wildflower” laws trilliums, orchids‐‐

14. Regulations on Collecting
•Same are listed species, Threatened and Endangered
species cannot be taken on public land without a permit
•Those on private land also protected in theory
•Taking for research purposes through application
International Collecting
•Primary set of voucher duplicates should go to in country‐
institution(s)
•Most international permits require at least one complete set
deposited at national institution
•In country institution will often provide collecting‐
equipment, expertise
•Customary for types of new organisms to be deposited at
in country institutions (at least duplicates = isotypes)‐

15. International Collaboration
Involvement of in country personnel during collecting #‐
Many international permits require in country assistant‐
(e.g., graduate student) as commitment to sharing of
expertise
Foreign researcher often expected to cover expenses of in‐
country assistant – Staff of in country herbarium may often‐
“double” as field assistants, liaisons for permits, and tend
to processing/mailing of vouchers after expedition

16. •Amount of material collected should not exceed 100-150gms
unless permission granted.
•In case of partnership with foreign countries 60% of the
income arising from budget should be given to country
organization
•Country receives 51% of royality arising from external
collaboration that result in marketable produtcs.
•No country should give exclusive rights to the external parties.
•Complete evaluation results should be supplies to the
supplying country within 6-9 months
•It there is chance of exploitation , cost of sustainable
harvesting and alternative supplies must be borne of external
organizations.
•Contribution should be recognized through co-authorship
•Where possible screening of the extracts should be carried out
in country of origin