This includes the study of various novel compounds obtained from marine organisms

1. MARINE PHARMACOGNOSY
INTRODUCTION:
- Marine pharmacognosy is a sub-branch of pharmacognosy, which is mainly
concerned with the naturally occurring substances of medicinal value from
marine source.
- In the western medicine agar, alginic acid, carrageenan, protamine sulphate,
spermaceti and cod and halibut liver oils are the established marine
medicinal products.
Marine products are of two types:
Contemporary products Classical products
1. Macroalgae or seaweeds: 1. Antibacterial agents:
Eg: Cephalosporin and Istamycin
2.Anticoagulants:
treatment of iodine deficiency
states such as goiter Eg: Carragenan, Fucoidin
2. Some sea weed utilized as
Vitamins 3. Anti-cancer agents:
treatment of anaemia during Eg: Bryostatins and Dolastatins

2. pregnancy. 4. Anti-viral agents:
3. Vermifuges,hypochloesterolaemic
and hypoglycemic agent. Eg: Ara A and C, Avarol and
e.g. Cystoseria barbata, Avarone
Sargassum confusam 5. Anthelmintic agents:
And Jania rubens
Eg: Kainic acid and Domoic acid
MARINE ORGANISMS AS POTENTIAL SOURCE OF DRUGS
- The information is used in exploring new sources of economic materials,
precursors for the synthesis of complex chemical substances and compounds
of novel chemical structure,.
- The extracts from marine organisms had been evaluated for various
biological activities. This has led to the isolation of substances possessing
antimicrobial, antibiotic, antiviral, anticancer, cardioactive,
antiinflammatory, anthelmintic, anticoagulant neurophysiological and
insecticidal activities.
- Many of the marine compounds have shown promising biological properties
but have complicated chemical structures, the synthesis of which would be
hard and expensive. These organisms are valuable as source of new
biologically active chemical structures,

3. 1. ANTIVIRAL AGENTS
a) Ara-A: It is a semisynthetic antiviral agent based on the arabinosyl
nucleoside isolated from the marine sponge Tethya crypta. The
compound shows a prominent therapeutic activity.
b) Avarol and Avarones: These two sesquiterpene benzenoids are derived
from the sponge Disidea avara. It has exhibited strong anti-HIV activity
against the human immunodeficiency virus (HIV). It shows the greater
promises in the treatment of AIDS.

4. 2. ANTI-MICROBIAL COMPOUNDS:
A) Cepahlosporins: The compound Cephalosporin C is isolated from
fungus Cephalosporium acremonium.
Uses It is used as an antibiotic drug against microbes
2) Istamycin: These are the fermentation products of marine organisms,
Streptomyces lenjimariensis.
Uses: They have activity against both gram positive and gram negative
bacteria

5. 3. ANTICANCER AGENTS
1. Bryostatin: Isolated from Bugula neritina a bryozoal marine organism
showed highly potent antineoplastic activity in an extremely low dose
level. Bryostatins triggers activation and differentiation of periphereal
blood cells from lymphocytic leukemia patients.
2. Dolastatins: It is isolated from the sea hare i.e Dolabella auricularia. The
highly cytotoxic compounds are Dolastatin -10 and Dolastatin-H.
3.Ara-C: It is the synthetic anticancer agents also called cytosine
arabinoside, It originates from the natural marine substance
spongothymidine isolated from Caribbean sponge Cryptotethya crypta)
4. CARDIOVASCULAR AGENTS:
1. Eledoisin Eledoisin, a peptide compound has been isolated from posterior
salivary glands of Cephalopod Eledone moschata
Uses: It has shown potent hypotensive and vasodilatory activity.
2. Octopamine: Octopamine a simple phenolic derivative isolated from
salivary glands of Octopus vulgaris, Octopus. macropus and Eledone
moschata

6. Uses: Cardiotonic activity.
5. ANTIINFLAMMATORY AGENTS:
1. Marine bi-indole derivatives: Isolated from marine Cyanobacterium
Rivularia firma.
Uses: anti-inflammatory activity in the models of carrageenan-induced
rat paw odema and kaolin induced rat paw oedema.
2. Pseudopterosins: These are group of diterpene glycosides isolated from
Caribbean octocorals.
Examples : Pseudopterosins-I and Seco-pseudopterosins-3
Uses: Strong anti-inflammatory activity.
6. ANTICOAGULANTS:
1. Carrageenans: Isolated from Condrus crispus and have shown
anticoagulant effect through inactivation of thrombin.
2. Fucoidin : Isolated from the brown algae Fucus vesiculosus has shown a
very good anticoagulant activity
7. ANTHELMINTIC :
1. Kainic acid: It is obtained from red algae Digenea simplex.
Uses: Used against parasitic round worm and tape worm.
2. Domoic acid: It is obtained from red algae Chondria armata.
Uses: Used in treatment of ascariasis and is effective against in expelling
another parasitic pin worms.

7. 8. MARINE TOXINS: Many marine organisms produce potentially toxic
compounds which may work for their safety and protect them from
predators. These toxins may pose potential hazards to human health. Many
of these toxins had also shown remarkable biological activities in
comparatively lower doses. Some of these marine toxins are discussed
below:
1. Tetrodotoxin:
It is a potent neurotoxin
produced by the pufferfish of family Tetraodontidae.
Uses: cardiovascular and neurophysiological activity in experimental animals
2. Saxitoxin:
It is a purine skeleton containing toxic compound
produced by the Saxidomus giganteus
Uses: produces a marked hypotensive effect
3. Ciguatoxin:
it is a poisonous compound
found in the dinoflagellate Gambierdiscus toxicus.
Uses: cardiovascular and neurophysiological properties.
4. Lophotoxin:
It is a diterpene lactone

8. present in the gorgonian corals of the genus Lophogorgia.
Uses: It produces an irreversible postsynaptic blockage at neuromuscular
junction