[Chemical and pharmacological progress on usnic acid and its derivatives].

Usnic acid and its derivatives, a group of organic molecules with great importance, are characteristic to lichens, possessing pharmacological activities such as anti-virus, anti-bacteria, anti-humor, anti-inflammatory, analgesic, and anaesthetic effects. Many of them have been widely used as medicine, but also bring side effects such as dermatitis and liver damages. In the past decades, great efforts by isolation, organic synthesis, and structure modification methods were put on discovery of UA derivatives with higher biological activities or less side effects. This paper describes herein the most progress on natural sources, isolation and structure elucidation, structural characteristics, synthesis and modification results, pharmacological activities and toxicities of UA and its derivatives, hopefully to provide valuable reference for further research.

[Chemical constituents from stems of Ilex asprella].

Phytochemical investigation on the stems of Ilex asprella by using various chromatographic techniques led to the isolation of 13 compounds. By spectroscopic analyses and comparisons the spectral data with those in literatures, these compounds were identified as salicifoneoliganol(1), rel-(7R,8S)-3,3',5-trimethoxy-4',7-epoxy-8,5'-neolignan-4,9,9'-triol 9-ß-D-glucopyranoside(2),(+)-cycloolivil(3),(+)-syringaresinol-4'-O-ß-D-monoglucoside(4), liriodendrin(5), caffeic acid (6), 3,4-dihydroxy-5-methoxybenzaldehyde(7), benzene-1,2,4-triol(8), 3,4,5-trimethoxyphenyl-1-O-ß-D-apiofuranosyl(1″→6')-glucopyranoside(9), aeculetin(10), cryptochlorogenic acid ethyl ester(11), chlorogenic acid ethyl ester(12), and rel-5-(3S,8S-dihydroxy-1R,5S-dimethyl-7-oxa-6-oxobicyclo [3,2,1]oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid(13). Among them, compounds 7, 8, 11, and 13 were isolated from genus Ilex for the first time, and 1-3, 9, 10, and 12 were isolated from this speciesfor the first time. The anti-inflammatory assay results of these compounds showed that compounds 1 and 9 showed moderate inhibitory effect against NO production in RAW 267. 4 cells with IC50 values of 35.7 and 50.6 µmol•L⁻¹, in vitro respectively, whereas compound 10 showed weak inhibition(IC50 value 98.7 µmol•L⁻¹).

[A phytochemical and pharmacological advance on Ilex asprella].

Ilex asprella is one of representative medicinal plants in South of the Five Ridges of China. The roots and rhizomes of I. asprella have the effects of clearing heat and detoxifying, stimulating salvia, and reducing thirst, which has been used to treat wind-heat cold, acute and chronic pharyngitis, and sore throat. Contemporary studies showed that I. asprella contains the major triterpenoids and glycosides, phenolic acids, and minor steroids. The extracts and compounds show activities of anti-inflammatory, antiviral, anti-tumor, and regulating lipid metabolism.The present paper summarizes a phytochemical and pharmacological advance on this species to provide reference for clarification of its pharmacologically active ingredients, quality evaluation, and further explorations.

[Phenolic constituents from lichen Usnea longissima].

Sixteen compounds were isolated from lichen Usnea longissima using of various chromatographic techniques including silica gel, Sephadex LH-20, ODS, and semi-preparative HPLC. By spectroscopic data analyses, their structures were identified by as useanol(1), lecanorin(2), 3-hydroxy-5-methylphenyl 2-hydroxy-4-methoxy-6-methylbenzoate(3), lecanorin E(4), 3'-methylevernic acid(5), evernic acid(6), barbatinic acid(7), 3,7-dihydroxy-1,9-dimethyldibenzofuran(8), orcinol(9), O-methylorcinol(10), methyl orsellinate(11), methyl everninate(12), 2,5-dimethyl-1,3-benzenediol(13), 2-hydroxy-4-methoxy-3,6-dimethyl benzoic acid(14), ethyl everninate(15), and ethyl 2,4-dihydroxy-6-methylbenzoate(16). Compound 1 was obtained as a natural product for the first time, and 3,4, 8,10,12, and 13 were isolated from Usneaceae family for the first time. Compound 1, 8, and 13 showed significant anti-inflammatory activity against NO production in RAW 267.4 cells with IC50 values of 6.8, 3.9 and 4.8 µmol•L⁻¹, respectively, compared with the positive controls curcumin(IC50 15.3 µmol•L⁻¹) and indomethacin(IC50 42.9 µmol•L⁻¹).