Lignan
The lignans are a large group of low molecular weight polyphenols found in plants, particularly seeds, whole grains, and vegetables.[1] The name derives from the Latin word for "wood".[2] Lignans are precursors to phytoestrogens.[1][3] They may play a role as antifeedants in the defense of seeds and plants against herbivores.[4]
Biosynthesis and metabolism
-
Matairesinol, illustrating the dibenzylbutyrolactone motif -
Secoisolariciresinol, illustrating the 9,9'-dihydroxydibenzylbutane motif -
Justicidin A, illustrating the arylnaphthalene motif -
Pinoresinol, illustrating the furanofuran motif -
Steganacin, illustrating the dibenzocyclooctadienelactone motif -
Podophyllotoxin, illustrating the aryltetralin motif
Lignans and lignin differ in their molecular weight, the former being small and soluble in water, the latter being high polymers that are undigestable. Both are polyphenolic substances derived by oxidative coupling of monolignols. Thus, most lignans feature a C18 cores, resulting from the dimerization of C9 precursors. The coupling of the lignols occurs at C8. Eight classes of lignans are: "furofuran, furan, dibenzylbutane, dibenzylbutyrolactone, aryltetralin, arylnaphthalene, dibenzocyclooctadiene, and dibenzylbutyrolactol."[5]
Many lignans are metabolized by mammalian gut microflora, producing so-called enterolignans.[6][7]
Food sources
Secoisolariciresinol and matairesinol were the first plant lignans identified in foods.[1] Typically, lariciresinol and pinoresinol contribute about 75% to the total lignan intake, whereas secoisolariciresinol and matairesinol contribute only about 25%.[1]
Foods containing lignans:[1][9]
| Source | Lignan amount |
|---|---|
| Flaxseeds | 85.5 mg per oz (28.35 g) |
| Sesame seeds | 11.2 mg per oz |
| Brassica vegetables | 0.3-0.8 mg per half cup (125 ml) |
| Strawberries | 0.2 mg per half cup |
Prevalence and health effects
Lignans are the principal source of dietary
A 2021 review found that lignans have a positive effect on lipid profiles of patients with dyslipidemia related diseases.[10] As of 2022 there is limited evidence that dietary intake of lignans is associated with a reduced cancer and cardiovascular disease risk.[1]
See also
- Herbalism
- Pharmacognosy
- Flavonolignan
References
- ^ a b c d e f g h i j k "Lignans". Micronutrient Information Center, Linus Pauling Institute, Oregon State University. 2010. Retrieved 31 July 2017.
- ^ From lign- (Latin, "wood") + -an (chemical suffix).
- PMID 21762105.
- PMID 16311631.
- S2CID 6276953.
- S2CID 31753060.
- PMID 11453749.
- ^ .
- PMID 15877880.
- PMID 34635132.)
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