Antioxidant and Biocidal Activities from Natural Sources: an Overview - Natural Antioxidants and Biocides from Wild Medicinal Plants - page 1

1 Antioxidant and Biocidal
Activities from Natural Sources:
an Overview

Carlos L. Céspedes*
Departamento Ciencias Básicas, Universidad del
Bío-Bío, Chillán, Chile

1.1 Introduction

Despite considerable progress towards
characterizing compounds that inhibit growth
of insect pests and weeds, evidence for an
ecological role for these compounds is poor.
Even if a broad range of biocides of sufficient
promise is discovered, major hurdles must be
overcome before the compounds can be com-
mercially exploited.
A number of recent phytochemical
studies have been directed to identifying
biocides of botanical origin. Anthocyanins,
diterpenes, triterpenes, sesquiterpene lac-
tones, coumarins, flavonoids and phenyl-
propanoids have been isolated from, for
example, the Anacardiaceae, Agavaceae,
Asteraceae, Celastraceae, Elaeocarpaceae,
Fabaceae, Leguminoseae, Loranthaceae,
Meliaceae, Plantaginaceae, Rhamnaceae,
Scrophulariaceae and Simaroubaceae fami-
lies. Many of these natural compounds
and some of their chemical derivatives pos-
sess antioxidant, antifungal, antibacterial,
insecticidal, insect-growth-regulatory (IGR)
or antifeedant activities. Much less is known
about these and other plants from Latin
America and the effects of their constituent
compounds on bacteria, fungal and insect
pests. In addition, a large proportion of these
compounds also demonstrated antioxidant

Plant natural products derived from isopre-
nyl pyrophosphate, phenylalanine and the
phenylpropanoid pathway are impressive in
their chemical diversity and are the result of
plant evolution that has selected for the
acquisition of large repertoires of structural
and defensive compounds, all derived from
a phenylpropanoid backbone via the plant-
specific shikimic acid pathway. These com-
pounds are important for plant growth,
development and responses to environmen-
tal stresses and thus can have a large impact
on agricultural productivity. Although plant-
based medicines containing phenylpropanoid-
derived active components have long been
used by humans, the benefits of specific fla-
vonoids and other phenylpropanoid-derived
compounds to human health and their
potential for long-term health benefits have
only been recognized more recently.
This overview brings together widely
scattered and disparate literature concerning
natural products from Latin-American plants;
in particular studies based on screening of
secondary metabolites are reviewed in the
context of the development of new antioxi-
dants and biocides.

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