This document discusses resins and resin combinations. It defines resins as complex secretions or exudations from plants that can be solid or semi-solid. Resins frequently occur mixed with volatile oils, gums, or both, forming combinations like oleoresins, gum-resins, and oleo-gum-resins. The document discusses the preparation, chemical composition, and examples of resins like colophony and cannabis. It also examines oleo-gum resins such as myrrh and balsams like benzoin. Tests for identifying specific resins are provided.

1. Phytochemistry
Resins and Resin Combinations
By
Dr. Mostafa Mahmoud
Hegazy

2. Definition
Resins is a term applied to indicate a group of solid or semi-solid substances
of complex chemical nature They are brittle secretions or exudations of plant
tissues, produced either normally or due to pathogenic conditions
Resins is a term applied to indicate a group of solid or semi-solid substances
of complex chemical nature They are brittle secretions or exudations of plant
tissues, produced either normally or due to pathogenic conditions
Resins occur frequently in homogeneous mixtures with either
volatile oils or gums or both to form:
Resin Combinations
Oleoresins Gum-resins Oleo-gum-resins
Biogenesis
1- Oxidation products of terpenes, or
2- Final products of destructive metabolism.

3. Preparation of resins
I- Natural resins are those collected from the plants.
II- Prepared resins (or resin combinations), these are obtained
by one of the following methods:
1- Extracting the plant containing a resin with alcohol then the
solvent is either evaporated or the solution poured in water to
precipitate the resin.
2- Extracting the plant containing oleoresin with ether or
acetone followed by distillation to remove the oil.
3- Extracting the plant containing gum resin with alcohol in
which the gum is insoluble.

4. Chemical Composition of Resin
1) Resin acids:
• These are diterpenoid oxyacids, usually combining the properties
of carboxylic acids and phenols.
• Their metallic salts are known as resinates.
• Examples are abietic acid in colophony and commiphoric acid in
myrrh.
2) Resin alcohols:
• These are complex alcohols of high molecular weight.
• They are subclassified into resinotannols and resinols.
• Resinotannols give a tannin reaction with ferric chloride e.g.
Siaresinotannol and sumaresinotannol (Benzoin).
• Resinols give no color reaction with ferric chloride e.g. benzoresinol
from benzoin and ammoresinol from ammoniacum.

5. 3) Resenes:
• These are complex neutral oxygenated substances devoid
of characteristic chemical properties.
• They do not form salts or esters.
• They are resist hydrolysis with alkalis.
• They resist the action of oxidizing agents.
• They generally used in the manufacture of varnishes.
4) Glycosidal mixtures:
• These are complex mixtures yielding on hydrolysis sugars
and complex resin acids as aglycones.
• Ex. Jalapin from jalap resin

6. Example of Resins
1) Colophony
Source: Colophony is the solid resin obtained from Pinus species
especially Pinus palustris [Fam. Pinaceae].
Constituents:
1) Resin acids: 80-90% of diterpene acids (Abietic acid)
2) Esters of fatty acids
3) Resene: represented by a small proportion of hydrocarbons.
Chemical Test:
Copper acetate test (for abietic acid)
Extract the powder with petroleum ether and filter. Shake the filtrate
with Cu acetate.
The petroleum ether layer turns green due to the formation of the
copper salt of abietic acid.

7. Uses:
In pharmaceutical industries:
Colophony is used as ingredient in cerates plasters
and ointments.
Commercially:
it is used in the manufacture of varnishes, paint
dryers, printing inks, soap, sealing wax, floor
coverings

8. Cannabis, Indian hemp, or Marihuana
Source: It consists of the dried flowering tops of the
pistillate plants (female plants) of Cannabis sativa
(Fam. Cannabinaceae). The resin is known in Arabia as
hashish
Constituents:
These are meroterpenoid compounds collectively known as
Cannabinoids.
The main active constituent of the resin:
(-)-∆9
-trans-tetrahydrocannabinol (∆9
-THC)
Other constituents isolated from the resin include
cannabinol, cannabidiolic acid, cannabichromene.

9. Purple color
Cannabis drug
- Extract the drug with methanol
- Evaporate to dryness
- Extract the residue with petroleum ether
- Filter
Filtrate
- Wash the with dilute Na2CO3
- Decolorize with charcoal and evaporate to dryness
Residue
Add drops of N/10 alcoholic KOH
Test for identification (Modified Beam’s test):
- Dilute with H2SO4 and water.

10. Uses:
• Sedative, hypnotic and anticonvulsant.
• Analgesic, anti-anxiety, antitussive
• Orally in the treatment of the nausea and
vomiting associated with cytotoxic drugs
used in cancer chemotherapy.

11. Oleo-gum-resins
Myrrh:
Source: Myrrh is obtained from the stem and branches
of Commiphora molmol Fam. Burseraceae
Constituents:
Volatile oil; terpenes, sesquit., esters, eugenol
Resin acid: composed of several constituents
including diterpenoid ether soluble fraction (α-β
and γ commiphoric acids),and ether insoluble
fraction (α- and β-heerabomyrrholic acids)
Resenes, phenolic compounds, Gum(gal., arab.,
glucuronic acid, oxidase), and bitter principle.

12. Tests for identification:
The residue obtained on evaporation of the ethereal
extract of the resin when treated with Conc. HNO3 or
exposed to bromine vapors → violet color.
Uses:
Externally: Myrrh is used as a protective.
Internally: It acts as stimulant and stomachic.
It is used in mouth-washes as
astringent and antiseptic.
Anti-bilharzial

13. Asafoetida Galbanum Ammoniacum
Obtained by incision from
root and rhizomes of
Ferula foetida,
Umbelliferae
From stems of Ferula
galbaniflua, Umbelliferae
From stems of Dorema
ammoniacum,
Umbelliferae
Volatile oil with bad smell
due to sulphur
compounds
Volatile oil without bad
smell, no sulphur
compounds
Volatile oil without bad
smell, no sulphur
compounds
No free umbelliferone Contains free umbelliferone No free umbelliferone
Contains combined
umbelliferone
Contains combined
umbelliferone
No combined
umbelliferone
Ferulic acid Resin + KOH→
galbaresinotannol+umbellic
acid
Phenolic ammoresinol,
Salicylic acid
Used as carminative,
expectorant,
antispasmodic and
laxative in veterinary
medicine
Used as stimulant to the
skin in plasters
Used as stimulant to the
skin in plasters,
expectorant in chronic
bronchitis

14. Asafoetida Galbanum Ammoniacum
Gives blue
fluorescence with
amm. hydroxide
after hydrolysis by
HCl
Gives blue
fluorescence with
ammonium
hydroxide due to
free
umbelliferone
No blue fluorescence
with amm. hydroxide
before and after
hydrolysis by HCl
Freshly cut
surface+ drop
conc. sulfuric→
reddish-brown
Chlorinated soda →
deep orange-red due
to ammoresinol
Freshly cut
surface+ drop 50%
nitric→ green
KOH →yellow,
Ferric chloride →
violet (Salicylic )

15. Balsams
“Balsams” are resinous mixtures that contain cinnamic acid,
benzoic acid, or both, or esters of these acids
Benzoin
Benzoin is a pathologic product developed by incising the
bark. The balsam is collected two months after exudation
when it becomes less sticky
Source: Benzoin is the balsamic resin obtained from
Styrax species Fam. Styraceae
Sumatra benzoin: is obtained from Styrax benzoin
Siam benzoin: is obtained from S. tonkinensis.

16. Siambenzoin Sumatra Benzoin
Coniferyl benzoate
Coniferyl alcohol
Free balsamic acids: cinnamic and
benzoic
free benzoic acid Esters of balsamic acids.
A triterpenoid
)Siaresinol(
Triterpenoid acids:
19-hydroxyoleanolic acid
6-hydroxyoleanolic acid.
Constituents:
Uses:
Perfumery, Antiseptic, Stimulant, Expectorant and
Diuretic properties.

17. Tests foridentification
Siam benzoin:
Sumatra benzoin:
(c.f. Sumatra benzoin)Ethereal solution of the resin
conc. H2SO4
Deep purplish color
(c.f. Siam benzoin).Ethereal solution of the resin
KMnO4
Faint odor of benzaldehyde
Warm

18. For more educational
lectures
cognosy4all.blogspot.com

19. cognosy4all.blogspot.com
Pharmacognosy and Herbal Medicine Dr. Mostafa