Lignans are complex diphenolic compounds representing
phytoestrogens and occur widely across the plant kingdom. Formed by the coupling of two
coniferyl alcohol residues,
lignans constitute major plant "specialized metabolites" with exceptional biological attributes that aid in plant defence and provide health benefits in humans by reducing the risk of ailments such as
cancer, diabetes etc. Linseed (Linum usitatissimum L.) is one of the richest sources of
lignans followed by cereals and legumes. Among the various types of
lignans,
secoisolariciresinol diglucoside (SDG) is considered as the essential and nutrient rich
lignan in linseed.
Lignans exhibit established
antimitotic,
antiviral and anti-
tumor properties that contribute to their medicinal value. The present review seeks to provide a holistic view of research in the past and present times revolving around
lignans from linseed and its allied species. This review attempts to elucidate sources, structures and functional properties of
lignans, along with detailed biosynthetic mechanisms operating in plants. It summarizes various methods for the determination of
lignan content in plants. Biotechnological interventions (in planta and in vitro) aimed at enriching
lignan content and adoption of integrative approaches that might further enhance
lignan content and medicinal and nutraceutical value of Linum spp. have also been discussed.