Kaempferol (3,4′,5,7-tetrahydroxyflavone) is a natural flavonol, a type of

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

, found in a variety of plants and plant-derived foods including kale,

bean A bean is the seed of some plants in the legume family (Fabaceae) used as a vegetable for human consumption or animal feed. The seeds are often preserved through drying (a ''pulse''), but fresh beans are also sold. Dried beans are traditi ...

s, tea,

spinach Spinach (''Spinacia oleracea'') is a leafy green flowering plant native to Central Asia, Central and Western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common vegetable consumed eit ...

, and

broccoli Broccoli (''Brassica oleracea'' var. ''italica'') is an edible green plant in the Brassicaceae, cabbage family (family Brassicaceae, genus ''Brassica'') whose large Pseudanthium, flowering head, plant stem, stalk and small associated leafy gre ...

. It is also found in propolis extracts. Kaempferol is a yellow crystalline solid with a melting point of . It is slightly soluble in water and highly soluble in hot

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

, ethers, and DMSO. Kaempferol is named for 17th-century German naturalist Engelbert Kaempfer.Kaempferol
at

Merriam-Webster Merriam-Webster, Incorporated is an list of companies of the United States by state, American company that publishes reference work, reference books and is mostly known for Webster's Dictionary, its dictionaries. It is the oldest dictionary pub ...

.com; retrieved October 20, 2017

Natural occurrence

Kaempferol is a secondary metabolite found in many plants, plant-derived foods, and traditional medicines. Its flavor is considered bitter.

In plants and food

Kaempferol is common in Pteridophyta, Pinophyta, and Angiospermae. Within Pteridophyta and Pinophyta, kaempferol has been found in diverse families. Kaempferol has also been identified in Dicotyledons and Monocotyledons of Angiosperms. The total average intake of flavonols and flavones in a normal diet is estimated as 23 mg/day, to which kaempferol contributes approximately 17%. Common foods that contain kaempferol include:

apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

grape A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus ''Vitis''. Grapes are a non- climacteric type of fruit, generally occurring in clusters. The cultivation of grapes began approximately 8,0 ...

tomato The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible Berry (botany), berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originate ...

es,

green tea Green tea is a type of tea made from the leaves and buds of the '' Camellia sinensis'' that have not undergone the withering and oxidation process that creates oolong teas and black teas. Green tea originated in China in the late 1st millenn ...

potato The potato () is a starchy tuberous vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground stem tubers of the plant ''Solanum tuberosum'', a perennial in the nightshade famil ...

es,

onion An onion (''Allium cepa'' , from Latin ), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus '' Allium''. The shallot is a botanical variety of the onion which was classifie ...

, Brussels sprouts, squash, cucumbers,

lettuce Lettuce (''Lactuca sativa'') is an annual plant of the family Asteraceae mostly grown as a leaf vegetable. The leaves are most often used raw in Green salad, green salads, although lettuce is also seen in other kinds of food, such as sandwiche ...

green bean Green beans are young, unripe fruits of various cultivars of the common bean ('' Phaseolus vulgaris''), although immature or young pods of the runner bean ('' Phaseolus coccineus''), yardlong bean ( ''Vigna unguiculata'' subsp. ''sesquipedali ...

peach The peach (''Prunus persica'') is a deciduous tree first domesticated and Agriculture, cultivated in China. It bears edible juicy fruits with various characteristics, most called peaches and the glossy-skinned, non-fuzzy varieties called necta ...

es, blackberries, raspberries, and

. Plants that are known to contain kaempferol include ''

Aloe vera ''Aloe vera'' () is a succulent plant species of the genus ''Aloe''. It is widely distributed, and is considered an invasive species in many world regions. An evergreen perennial plant, perennial, it originates from the Arabian Peninsula, but ...

'', '' Coccinia grandis'', '' Cuscuta chinensis'', '' Euphorbia pekinensis'', '' Glycine max'', '' Hypericum perforatum'', ''

Pinus sylvestris ''Pinus sylvestris'', the Scots pine (UK), Scotch pine (US), Baltic pine, or European red pine is a species of tree in the pine family Pinaceae that is native plant, native to Eurasia. It can readily be identified by its combination of fairly s ...

'', '' Moringa oleifera'', '' Rosmarinus officinalis'', '' Sambucus nigra'', '' Toona sinensis'', and '' Ilex''. It also is present in endive.

Biosynthesis

The biosynthesis of kaempferol occurs in four major steps: *

Phenylalanine Phenylalanine (symbol Phe or F) is an essential α-amino acid with the chemical formula, formula . It can be viewed as a benzyl group substituent, substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of ...

is converted into 4-coumaroyl-CoA *4-Coumaroyl-CoA combines with three molecules of malonyl-CoA to form naringenin chalcone (tetrahydroxychalcone) through the action of the enzyme chalcone synthase *Naringenin chalcone is converted to naringenin and then a hydroxyl group is added to form dihydrokaempferol *Dihydrokaempferol has a double bond introduced into it to form kaempferol The amino acid phenylalanine is formed from the Shikimate pathway, which is the pathway that plants use in order to make aromatic amino acids. This pathway is located in the plant plastid, and is the entry to the biosynthesis of phenylpropanoids. The phenylpropanoid pathway is the pathway that converts phenylalanine into tetrahydroxychalcone. Flavonols, including kaempferol, are products of this pathway.

Notes

External links

*
Flavonoid composition of tea: Comparison of black and green teas
{{Purinergics Antidepressants Xanthine oxidase inhibitors Flavonoid antioxidants Phytoestrogens Progestogens Tetrols Resorcinols