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17.1 Introduction
Phenolics are a diverse group of aromatic compounds. Among them stilbenoids are
the important compounds displaying a wide variety of biological activities. Stilbenes
are low molecular weight phenolics, occur naturally in various plants (Hart 1981).
They protect plants from cold, heat, fungal and bacterial infections and the growth
of moulds. Grapes and related products are considered as the important sources for
stilbene (Goldberg 1995 and Mattavi et al. 1995).
Recently there is an increasing interest in the study of stilbenes because of their
medicinal value. Several reports are available relating to the moderate consumption
of wine and their beneficial effects on human health. Red wines are reported to
contain stilbenes (Siemann and Creasy 1992; Mattavi 1995; Mattavi et al. 1995).
Wine seems to be the most potent cardio-protective beverage (Klatsky et al. 1992).
There is an inverse relationship between wine consumption and incidence of coronary disease, the so-called ‘French Paradox’ (Barnard and Linter 1992). It has been
suggested that the phenolic substances in the red wine may be the reason for these
beneficial effects because of its antioxidant properties. Wine polyphenols have also
been reported to have anti-carcinogenic properties delaying the onset of tumour in
transgenic mice (Clifford et al. 1996). Stilbenes protect lipoproteins from oxidative
damage.
Stilbene derivatives are formed during fermentation. So they are found in fermented preparations along with the production of alcohol. Asavas and arishtas are
fermented alcoholic preparations. The process is such that alcohol is self-generated
to a particular level with maximum alcoholic content being 15%. Arishta is a sweet,
relishing, carminative and emacinating tonic indicated in the treatment of several
diseases like piles, loss of appetite, heart diseases, tumour, epistaxis and tuberculosis. Stilbenes and their derivatives are present in these ayurvedic medicines (Barnard
et al. 1999). So stilbenes contribute to the medicinal value of these ayurvedic medicines to a great extent.
17.2 Sources of Stilbenes
Stilbenes are synthesized by a wide range of plant species, including
Dipterocarpaceae, Cyperaceae, Gnetaceae, Pinaceae, Leguminosae, Myrtaceae,
Moraceae, Fagaceae, Liliaceae and Vitaceae. They are commonly found in the
roots, barks, rhizomes and leaves (Aedin et al. 2000). Major dietary sources of stilbene include grape, peanuts, soy and Itadori tea, which have long been used in Japan
and China as a traditional remedy for heart diseases and strokes. Analysis of these
sources revealed that peanuts, grape and Itadori tea mainly contain trans-resveratrol
glucoside. Red wines are primarily a source of cis- and trans-resveratrol. Peanuts
and grape contain less level of stilbenes, while red wine and Itadori tea contain large
amount of resveratrol. Stilbenes can also occur in oligomeric and polymeric forms
known as viniferins. They are induced by oxidative polymerization of monomer
resveratrol through the activity of peroxidase (Jean et al. 2006). Many viniferins
N. Vijayan et al.
17.1 Introduction
Phenolics are a diverse group of aromatic compounds. Among them stilbenoids are
the important compounds displaying a wide variety of biological activities. Stilbenes
are low molecular weight phenolics, occur naturally in various plants (Hart 1981).
They protect plants from cold, heat, fungal and bacterial infections and the growth
of moulds. Grapes and related products are considered as the important sources for
stilbene (Goldberg 1995 and Mattavi et al. 1995).
Recently there is an increasing interest in the study of stilbenes because of their
medicinal value. Several reports are available relating to the moderate consumption
of wine and their beneficial effects on human health. Red wines are reported to
contain stilbenes (Siemann and Creasy 1992; Mattavi 1995; Mattavi et al. 1995).
Wine seems to be the most potent cardio-protective beverage (Klatsky et al. 1992).
There is an inverse relationship between wine consumption and incidence of coronary disease, the so-called ‘French Paradox’ (Barnard and Linter 1992). It has been
suggested that the phenolic substances in the red wine may be the reason for these
beneficial effects because of its antioxidant properties. Wine polyphenols have also
been reported to have anti-carcinogenic properties delaying the onset of tumour in
transgenic mice (Clifford et al. 1996). Stilbenes protect lipoproteins from oxidative
damage.
Stilbene derivatives are formed during fermentation. So they are found in fermented preparations along with the production of alcohol. Asavas and arishtas are
fermented alcoholic preparations. The process is such that alcohol is self-generated
to a particular level with maximum alcoholic content being 15%. Arishta is a sweet,
relishing, carminative and emacinating tonic indicated in the treatment of several
diseases like piles, loss of appetite, heart diseases, tumour, epistaxis and tuberculosis. Stilbenes and their derivatives are present in these ayurvedic medicines (Barnard
et al. 1999). So stilbenes contribute to the medicinal value of these ayurvedic medicines to a great extent.
17.2 Sources of Stilbenes
Stilbenes are synthesized by a wide range of plant species, including
Dipterocarpaceae, Cyperaceae, Gnetaceae, Pinaceae, Leguminosae, Myrtaceae,
Moraceae, Fagaceae, Liliaceae and Vitaceae. They are commonly found in the
roots, barks, rhizomes and leaves (Aedin et al. 2000). Major dietary sources of stilbene include grape, peanuts, soy and Itadori tea, which have long been used in Japan
and China as a traditional remedy for heart diseases and strokes. Analysis of these
sources revealed that peanuts, grape and Itadori tea mainly contain trans-resveratrol
glucoside. Red wines are primarily a source of cis- and trans-resveratrol. Peanuts
and grape contain less level of stilbenes, while red wine and Itadori tea contain large
amount of resveratrol. Stilbenes can also occur in oligomeric and polymeric forms
known as viniferins. They are induced by oxidative polymerization of monomer
resveratrol through the activity of peroxidase (Jean et al. 2006). Many viniferins
N. Vijayan et al.