Evaluation of antifungal activities and structure-activity relationships of coumarin derivatives.

BACKGROUND: Osthol is a natural coumarin and lead compound that has been developed into commercial fungicides in China. Natural coumarins comprise five major subtypes: simple coumarins, linear furanocoumarins, angular furanocoumarins, linear pyranocoumarins and angular pyranocoumarins. Studies pertaining to the antifungal activities of linear pyranocoumarins are few, and no reports exist for the antifungal activities of angular pyranocoumarins. In order to discover more antifungal natural coumarins, we synthesised a series of simple natural coumarins and isolated several plant-based furanocoumarins and pyranocoumarins using previously described methods. The compounds were biologically evaluated against some plant fungal pathogens. RESULTS: Several of the 35 coumarins evaluated here exhibited strong activities against specific fungal species, including compound 25 (Pd-D-V, a linear pyranocoumarin), compound 26 (libanorin, an angular furanocoumarin) and compound 34 (disenecioyl khellactone, an angular pyranocoumarin). Compound 25 exhibited a high activity against Sclerotinia sclerotiorum (EC50 = 13.2 µg mL-1 ); compound 34 displayed a strong antifungal activity against Botrytis cinerea (EC50 = 11.0 µg mL-1 ). CONCLUSION: This study demonstrates that several natural coumarins (one linear pyranocoumarin and one angular pyranocoumarin in particular) exhibit strong antifungal activities. These results call for further studies, where these coumarins can be examined as potential lead compounds for developing novel antifungal agents. © 2016 Society of Chemical Industry.

Identification of species and materia medica within Angelica L. (Umbelliferae) based on phylogeny inferred from DNA barcodes.

DNA barcodes have been increasingly used in authentication of medicinal plants, while their wide application in materia medica is limited in their accuracy due to incomplete sampling of species and absence of identification for materia medica. In this study, 95 leaf accessions of 23 species (including one variety) and materia medica of three Pharmacopoeia-recorded species of Angelica in China were collected to evaluate the effectiveness of four DNA barcodes (rbcL, matK, trnH-psbA and ITS). Our results showed that ITS provided the best discriminatory power by resolving 17 species as monophyletic lineages without shared alleles and exhibited the largest barcoding gap among the four single barcodes. The phylogenetic analysis of ITS showed that Levisticum officinale and Angelica sinensis were sister taxa, which indicates that L. officinale should be considered as a species of Angelica. The combination of ITS + rbcL + matK + trnH-psbA performed slight better discriminatory power than ITS, recovering 23 species without shared alleles and 19 species as monophyletic clades in ML tree. Authentication of materia medica using ITS revealed that the decoction pieces of A. sinensis and A. biserrata were partially adulterated with those of L. officinale, and the temperature around 80 °C processing A. dahurica decoction pieces obviously reduced the efficiency of PCR and sequencing. The examination of two cultivated varieties of A. dahurica from different localities indicated that the four DNA barcodes are inefficient for discriminating geographical authenticity of conspecific materia medica. This study provides an empirical paradigm in identification of medicinal plants and their materia medica using DNA barcodes.

[Chemical constituents of Angelica nitida roots].

OBJECTIVE: To investigate the chemical constituents in the roots of Angelica nitida. METHODS: The chemical constituents were isolated by silica gel,their structures were identified by spectral analysis. RESULTS: Nine compounds were isolated and identified as isoimperatorin(I), imperatorin(II), cnidilin(III), beta-sitosterol(IV), isopimpinellin(V), phellopterin(VI), neobyakangelicol(VII), (3S)-2,2-dimethyl-3,5-dihydroxy-8-hydroxylmethyl-3,4-dihydro-2H,6H-benzo[1,2-b: 5,4-b'] dipyran-6-one(VIll) and byakangelicin (IX). CONCLUSION: All the compounds are isolated from the plant for the first time.

Five condensed furanocoumarins from the root of Heracleum candicans Wall.

Three new spirotrifuranocoumarins, canditririns C-E (1-3), a new spirotetrafuranocoumarin, canditetrarin A (4), and a new tetrafuranocoumarin, canditetrarin B (5), were isolated from the roots of Heracleum candicans Wall. Their structures were established using spectral methods.

Four novel furanocoumarin glucosides, candinosides A, B, C and D, from Heracleum candicans Wall.

Four novel furanocoumarin glucosides, candinosides A, B, C and D (1-4), were isolated from the roots of Heracleum candicans Wall. Their structures were established using chemical and spectral methods.

Chemical studies on the root of Heracleum candicans Wall. (Part 3).

Two new ester coumarins, candinols B and C (1 and 2), and three new coumarin dimers, candibirins F-H (3-5), were isolated from the roots of Heracleum candicans Wall. Their structures were established by using chemical and spectral means.

[Studies on the chemical constituents in roots of Angelica tianmuensis and A. megaphylla].

OBJECTIVE: To study the chemical constituents in roots of Angelica tianmuensis and A. megaphylla. METHODS: Compounds were isolated by column chromatography with silica gel, their structures were identified by spectral analysis. RESULTS: Another three compounds (ligustilone, 5-methoxyhamaudol, cimifugin) were obtained from the roots of Angelica tianmuensis, and another two compounds (ligustilone, angelol) were obtained from the roots of A. megaphylla. CONCLUSION: All the compounds are isolated in these two plants for the first time, and ligustilone is first found from Angelica L..

Chemical studies on the root of Heracleum candicans Wall.

Two new alkyl coumarins, isophellodenol C (1) and candinol A (2); four new spirobifuranocoumarins, candibirins B-E (3-6); and two trifuranocoumarins, canditririns A and B (7 and 8), were isolated from the roots of Heracleum candicans Wall. Their structures were established using chemical and spectral means.

Coumarins from the roots of Ligusticum multivittatum.

Five new coumarins, (+)-peujaponisin (1) and multivittans A-D (2-5), were isolated from the roots of Ligusticum multivittatum Franch., and their structures were established by spectral means.

Two isocoumarins from Pleurospermum angelicoides.

Two new isocoumarins, angelicoins A and B, were isolated from the roots of Pleurospermum angelicoides, and their structures were established by spectral means.

Bisabolane-type sesquiterpenes: liginvolones A-D from ligusticum involucratum.

Four new bisabolane-type sesquiterpenes, liginvolones A-D (1-4), a new coumarin, 4'-octanoyloxyosthenol (5), and 20 known constituents were isolated from Ligusticum involucratum. Their structures were elucidated on the basis of spectroscopic analyses and chemical methods.

Four coumarins from Heracleum yunngningense.

Four new coumarins (1-4) were isolated from the roots of Heracleum yunngningense HAND.-MASS. Their structures were established by spectral analyses.

Candibirin A, a furanocoumarin dimer isolated from Heracleum candicans WALL.

Candibirin A [systematic name: 9,9'-(1,4-dioxane-2,5-diyldimethylenedioxy)di(7H-furo[3,2-g]chromen-7-one)], a new furanocoumarin dimer, was isolated from Heracleum candicans WALL. (1)H NMR and MS spectra had indicated that the title compound was a dimer of heraclenin or heraclenol, but the linkage structure and its chirality were undetermined. The dioxane linkage, having the R,R configuration, has now been elucidated from dimethyl sulfoxide-solvated crystals, C(32)H(28)O(10).2C(2)H(6)OS. Candibirin A is thus a dimerization product from heraclenin formed by reaction at the epoxy group. Dimethylformamide-solvated crystals, C(32)H(28)O(10).C(3)H(7)NO, adopt a different conformation, with a folded structure that differs from the extended structure in the dimethyl sulfoxide solvate. However, the puckering of the dioxane linker unit is very similar in the two conformers. This result shows that the rotation of the ether bonds, in the linker between the furanocoumarin and dioxane moieties, causes the conformational flexibility of (I).

Sinodielides E-H, four new guaianolides, from the root of Sinodielsia yunnanensis.

Four new guaianolides, sinodielides E-H (1-4), were isolated from the root of Sinodielsia yunnanensis WOLFF. Their structures were established by spectral evidence.

Four guaianolides from Sinodielsia yunnanensis.

Four new guaianolides, sinodielides A-D (1-4), were isolated from Sinodielsia yunnanensis WOLFF together with a known polyacetylene, falcarindiol, and two known coumarins, bergapten and scopoletin. Their structures were established by spectral and X-ray analyses.