Biology Reference
In-Depth Information
that live in the sponge tissue. Only a few of these symbionts have been
cultivated so far. Another promising way to utilize the bioactive potential
of the microorganisms is the cloning and heterologous expression of
enzymes involved in secondary metabolism (Thakur et al., 2005).
Several countries have initiated serious work for the discovery of
drugs from marine sources, particularly from corals. Australian research
on marine natural products from coral organisms of the Great Barrier
Reef has yielded a number of compounds. (Volkman, 1999). Cytotoxic
diterpenes, sesquiterpenoids and furan derivatives have been isolated
from Formosan soft corals in Taiwan. Among the identifi ed compounds,
the toxicity property of some has been investigated in various cancer
cell lines. Many of these bioactive compounds are ready for further
clinical trials to establish their potential use as drugs against diseases.
In the U.S., the National Sea Grant College Program, under the National
Oceanic and Atmospheric Administration is undertaking active research
in the area. Recent interest in the area is also depicted by collection of
thousands of marine organism samples and identifi cation of a number
of promising potential drugs for treating cancer, Alzheimer's, malaria,
AIDS and other ailments by researchers at t
he U
niversity of Miami. The
Sea Grant Program has compiled information on marine-based natural
products of biomedical signifi cance. Information provided for each
product entry includes compound source, bioactivity, and clinical status,
as well as structural and chemical attributes and commercial development
highlights. Some of them are now at various stages of development (HBOI,
2006; Proksch, 2002). In India, the government has taken up a national
coordinated program on development of drugs from the ocean to harness
potential bioactive substances, which is being implemented by the Central
Drug Research Institute, Lucknow, Centre for Advanced Studies in Marine
Biology of the University of Annamalai, Tamil Nadu and other institutes.
Over 4000 samples collected from 800 different species of marine fl ora
and fauna were examined for bioactive compounds, giving about 500
isolates exhibiting various biological activities and identifi cation of two
compounds, one having anti-diabetic and another, having anti-hyper-
lipidemic activity (Sudarsanam and Anita Devi, 2004). Table 7.4 indicates
some drugs isolated from sponges and their activities
MARINE BACTERIA
Marine bacteria are involved in nutrient cycling and the degradation of
marine organic matter. Generally they form part of a symbiotic association
with hosts such as algae. Recent extensive chemical investigations on
microbial extracts from marine environments have led to the discovery
of a variety of secondary metabolites (Jensen and Fenical, 2005). A survey
