According to the research, propolis contains active ingredients such as kaempferol
and caffeic acid that stimulated the start of the hair growth cycle in the subjects' bald skin.
These constituents include campesterol, kaempferol
, beta-sitosterol, and quercetin (Duke, 1992).
It also contains a flavonoid, kaempferol
, which protects against ovarian cancer.
australis seed has been demonstrated to contain both kaempferol
and astragalin majorly while the stem contains a high level of kaempferol
The tested compounds were purchased from Sigma-Aldrich, Czech Republic (anisic acid, apigenin, caffeic acid, catechin, cinnamic acid, coumaric acid, cyanidin-chlorid, delphinidin-chlorid, 3,4-dihydroxybenzoic acid, epicatechin, ferulic acid, gallic acid, kaempferol
, luteolin, m-hydroxybenzoic acid, p-hydroxybenzoic acid, piceatannol, quercetin-dihydro, resveratrol, salicylic acid, syringic acid, tyrosol, luteolin-7-glucosid, myricetin, naringenin, sinapinic acid, and vanillic acid); HWI Analytik, Germany (chlorogenic acid); Roth, Germany (rutin); and Polyphenols Laboratories AS, Norway (delphinidin 3-O-[beta]-glucopyranoside, malvinidin 3-O-[beta]-glucopyranoside, peonidin 3-O-[beta]-glucopyranoside, and petunidin 3-O-[beta]-glucopyranoside).
In addition, kale has high levels of the flavonoids kaempferol
and quercetin, which help reduce inflammation, keep blood vessels healthy and prevent DNA damage that can lead to cancer.
Stock solutions of standard references were prepared in the HPLC mobile phase at a concentration range of 0.031-0.250mg [mL.sup.-1] for quercetin, rutin, and kaempferol
, and 0.006-0.250mg [mL.sup.-1] for caffeic acid and theobromine.
Led by professor and food chemist Alyson Mitchell, the study compared levels of two flavonoids--quercetin and kaempferol
in organic and nonorganic tomatoes.
In a ten-year comparison of the influence of crop management practices on the content of flavonoids in tomatoes, UC Davis researchers found that the ten-year mean levels of two important bio-flavinoids, quercetin and kaempferol
, were 79% and 97% higher in organic tomatoes.
Her tests with lab-cultured cells of a cancer known as "acute lymphoblastic leukemia" have provided additional evidence that three compounds occurring naturally in strawberries--ellagic acid, kaempferol
, and quercetin--can cause death, or significant damage, to certain lines of these leukemia cells.
The most prevalent ones in plants are hydroxylated ones like quercetin, myricetin, and kaempferol
, which protect against cataract development (blindness) as well as maintain health and food freshness through their antibacterial properties.
Cauliflower leaves, for example, contain kaempferol
glycosides and hydroxycinnamic acid derivatives which showed antioxidant activities in various assays.