Flavonoids and phenolic acids of Nepeta cataria L. var. citriodora (Becker) Balb. (Lamiaceae).

Luteolin 7-O-glucuronide, luteolin 7-O-glucurono-(1-->6)-glucoside, apigenin 7-O-glucuronide as well as free aglycones luteolin and apigenin have been isolated from lemon catnip herb (Nepeta cataria L. var citriodora). Luteolin 7-O-glucurono-(1-->6)-glucoside is probably a new compound, for the first time described. Two minor constituents of flavonoid fraction have been identified as apigenin 7-O-glucoside and luteolin 7-O-glucoside by means of HPLC method. The percentage of total flavonoids determined by use of spectrophotometric method was in the range from 0.30 to 0.46% of dry mass. In phenolic acid fraction, caffeic, rosmarinic and p-coumaric acids have been identified. Total amount of phenolic acids determined by spectrophotometric method was in the range of 0.75% to 1.4 % and the content of rosmarinic acid quantified by HPLC method fluctuated in the wide range from 0.06% to 0.15% depending on the sample. The results of the investigations showed that the composition of flavonoid compounds and phenolic acids in lemon catnip are similar to those in lemon balm (Melissa officinalis L.). The amount of flavonoids are similar in both plants, and the percentage of rosmarinic acid is about ten times lower in lemon catnip than in lemon balm. The presence of luteolin, apigenin and their glycosides, caffeic acid as well as the previously described terpenoids (ursolic acid, citral, nerol. geraniol) suggests the possibility of the use of lemon catnip herb as a constituent of phytopharmaceutical preparations with mild sedative, antispasmodic, antioxidative and antiinflammatory action.