Clove (Syzygium aromaticum) is medicinally powerful herb. Cloves are also known as Clovos, Lavang, Laung. In india, cloves are grown in Nilgiries, Tensaki Hills of Tamil Nadu state, Kottayam and Kollam district of kerala. It holds several phytochemicals. Major phytochemicals includes Eugenol, Eugenyl acetate and Beta-caryophyllene. Clove contains essential oils in its buds, leaves, stem and fruits. Clove owns major pharmacological activities like antioxidant, antimicrobial, anti-inflammatory, anticarcinogenic, antibacterial, antipyretic and analgesic, etc.

1. A Review On Syzygium
Aromaticum (Clove)
By Miss. Shruti Ashok Salve
Final year B. Pharmacy
Under the guidance of
Mr. Vinayak Gaware Sir

2. Introduction
Synomys:
Clove buds, Clove flowers, Lavang (Marathi), Laung
(Hindi)
Common Names:
Cloves, Carophyllus, Clovos, Caryophyllus
Botanical Names:
Eugenia caryophyllus, Syzygium aromaticum
Family: Myrtaceae

3. Biological Source:
Clove is obtained from flower buds of plant
Eugenia caryophyllus. It is tropical evergreen tree of
the family Myrtaceae.
Geographical Source:
Clove tree is a native of Indonesia. It is
cultivated mainly in Islands of Zanzibar, Pemba,
Brazil, Amboyna and Sumatra. It is also found in
Madagaskar, Penang, Mauritius, West Indies, India.
In India, Cloves are grown in Nilgiris, Tenkasi-Hills of
Tamil Nadu state. It is also cultivated in Kottayam
and Kollam district of Kerala.

4. Cultivation:
 The plant requires moist, warm and equable climate.
 Deep rich loamy soil with high humus content is
suitable for clove cultivation.
 Water logging of soil must be avoided. It is propagated
by the seed germination.
 Plants starts bearing after 7 - 8 years and a
satisfactory yield per hectare of the drug is achieved
only after 15 - 20 years of growth.
Plant seedlings

5. Collection:
Flower buds are
collected when their base
turns into crimson-red in
colour in dry weather from
August to December.
Natives climb on the tree
or put ladder for the
collection. The cloves are
dried in open air and their
stalks are separated. On
drying about 70% water is
lost.
Clove Harvesting

6. Microscopy:
T. S. of Hypanthium:
I. Epidermis: Single layered small cells and has very thick
cuticle.
II. Cortex: 3 different zones can be seen
a. The peripheral region with 2 to 3 layers of Oil glands.
b. The middle layer has few layers of vascular bundles.
c. In the inner portion, it has loosely arranged aerenchyma
cells.
III. Columella: The central cylinder contains thick walled
parenchyma.
Fig.(a) T.S. Passing through hypanthium

7. T. S. of Ovary:
The transverse section through the ovary shows
the epidermis and zones of oil glands, vascular bundles
and numerous ovules.
Fig.(b) T.S. Passing through Ovary

8. Phytochemical constituents of Clove:
Clove buds contains 15-20% of essential oil, which
is dominated by
 Eugenol (75-85%)
 Eugenyl acetate (15%)
 beta-caryophyllene (5-12%).
Other phytochemical constituents of clove are
Vanillin, Crategolic acid, tannins, gallotannic acid,
Methyl salicylate, Flavonoids Eugenin, kaempferol,
Rhamnetin, Eugenitin and Triterpenoids like Oleanolic
acid, Methyl amyl ketone, Methyl salicylate, Alpha &
Beta humulene, Benzaldehyde, Beta-ylangene and
chavicol.
The minor constituent like methyl amyl ketone,
methyl salicylate etc., are responsible for the
characteristic pleasant odour of cloves.

9. Volatile Constituents:
 Bud Oil:
Good quality clove buds contain 15-20% essential
oil. The oil is dominated by Eugenol (70-85%), Eugenyl
acetate (15%) and Beta-caryophyllene (5-12%), which
together make up 99% of the oil.
Clove yields
different types of volatile
oil which is extracted
from leaves, stem, buds,
fruits. These oils differ
considerably in yield and
quality. The chief
component of all the
types of oil is eugenol.

10.  Leaf Oil:
Clove leaves yield 3.0-4.8% essential oil. The
eugenol content in the leaves increased from 38.3 to
95.2% with maturity. Clove bud and leaf oil contain
various classes of compounds, e.g. monoterpenes,
sesquiterpenes, aldehydes and ketones.
 Clove Stem Oil:
Clove stem yields 6% volatile oil. The oil is a pale
to light yellow liquid containing 80.2% eugenol and 6.6%
beta-caryophyllene, besides several minor components.
 Fruit Oil:
Ripe fruits yield 2% of oil, which is comprised of
50-55% eugenol.

11. Pharmacological Activity of Clove:
 Anti-oxidant activity:
Antioxidants are the compounds which are
essential for the treatment of oxidative stress causing
memory deficit. Strong antioxidant activity of clove is
comparable to synthetic antioxidants like BHA (Butyl
Hydroxy Anisole) and pyrogallol. Eugenol (4-allyl-2-
methoxy phenol) & Eugenyl acetate a major phenolic
component from clove oil has the most powerful
antioxidant activity.
Eugenol Eugenyl acetate

12.  Anti-carcinogenic activity :
Clove essential oil has also been reported to show anti
carcinogenic activity. Several preliminary studies suggested
chemo-preventive role of clove oil, particularly in cases of
lung, skin and digestive cancers. Oleanolic acid, one of the
component of ethyl acetate extract of clove was found to be
responsible for its antitumor activity.
Eugenol shows better curative effects in skin cancer
and melanoma.
Oleanolic acid

13.  Anti-microbial activity :
Clove oil was found to be more effective than
sodium propionate (Standard food Preservative) against
some food borne microbes. Clove oil was found to be
very effective against Staphylococcus species. Amongst
the fungi, Aspergillus niger was found to be highly
sensitive to the clove oil. Clove oil shows antimicrobial
activity against some human pathogenic bacteria
resistant to certain antibiotics.
Gallic acid

14.  Anti-inflammatory activity :
Anti-inflammatory agent in clove oil is eugenol.
Aspirin eugenol ester, Ibuprofen eugenol ester and other
NSAID’s not only posssess the anti-inflammatory action
of aspirin & Ibuprofen but also can reduce toxic side
effects of of these two drugs on stomach and liver. Clove
also contains kaempferol, rhamnetin and beta-
caryophyllene which also contributed to clove’s anti-
inflammatory property.
Kaempferol Caryophyllene

15. Medicinal Uses :
 Clove is good for diabetic patients as it controls the
blood level of glucose.
 Eugenol in the clove prevents the formation of blood
clots.
 Topical application of clove oil relieves muscular cramps
and also relieves sore gums.
 Mixture of eugenol and zinc oxide is used for short-term
filling of dental cavities.
 Pure clove oil is used in aromatherapy of arthritis and
rheumatism.
 Application of one drop of clove oil can soothe
headaches.
 Inhalation of clove essential oil soothes various
respiratory conditions such as asthma, cold, cough,
bronchitis.

16. Conclusion :
Clove is medicinally powerful herb. It has physical
as well as mental health benefits. Clove buds contains
15-20% essential oil. The major pharmacological
activities of clove are antioxidant, antimicrobial, anti-
inflammatory, anti-carcinogenic, antiviral, antibacterial,
antifungal, antipyretic and analgesic, etc.
Cloves are also beneficial in maintains oral
health, relieves headache, diabetes management, liver
protection, boosts immunity, maintains respiratory
health, improves hair health, treats acne. Therefore
considering numerous medicinal uses and health
benefits from phytochemicals of clove there is adequate
extent for future research.