Contribution à l'étude phytochimique de Solidago virgaurea : application dans le domaine bucco-dentaire et étude de la variabilité phytochimique pour la création d'une filière

Toward the promotion of plant diversity of Maritime Alps, a common plant of the alpine area, Solidago virgaurea, was chosen to its inhibiting activity of Candida albicans yeast-hyphal conversion, a causal agent of opportunistic oral infections named candidiasis. In a first step, an aqueous extract of S. virgaurea was submitted to bioassay guided fractionation. This led to an active saponin-containing fraction from which eleven saponins were characterized by carrying out NMR experiments along with HRMS analyses. Five out of these were identified for the first time and bioassays showed that saponins activity varied according to the molecular structure of the compound. In a second step, the saponins composition of various S. virgaurea populations was studied qualitatively and quantitatively, using HPLC and HPTLC. Results demonstrated that saponins composition depends on various factors. Finally, the overall chemical composition of different S. virgaurea extracts was investigated searching for additional bioactivities. Among all the identified compounds, three new octulosonic acids were characterized and three phenolic compounds were found for the first time in S. virgaurea. Moreover, bioassays on extracts and fractions showed antioxidant, anti-tyrosinase activity and inhibition of cancer cell lines in vitro. Further bioassays have now to be completed. As a conclusion, this work was the starting point of an oral care product development and the setting-up of an innovative sector.Dans le but de valoriser la biodiversité végétale des Alpes-Maritimes, une plante commune dans cette région, Solidago virgaurea, a été sélectionnée pour son potentiel inhibiteur de la conversion levure-hyphe de Candida albicans, micro-organisme responsable d’infections bucco-dentaires de type candidose. Le fractionnement bioguidé de l’extrait aqueux a conduit à l’identification d’une famille de saponines particulièrement active. Parmi les onze saponines majoritaires caractérisées par RMN et HRMS, cinq se sont révélées être de nouvelles structures. Les tests biologiques ont néanmoins montré qu’elles n’étaient pas toutes actives contre la forme filamenteuse de C. albicans. Ces résultats ont conduit à une étude de la variabilité de la composition en saponines de plusieurs populations alpines de S. virgaurea. Trois méthodes de dosage des saponines ont été développées par HPLC et HPTLC. Les résultats ont démontré l'influence de différents facteurs sur la composition en saponines. Enfin, la composition globale de différents extraits de S. virgaurea a été étudiée dans le but d'identifier des activités biologiques complémentaires. Parmi les composés identifiés, trois nouveaux acides octulosoniques ont été caractérisés, aux côtés de trois composés phénoliques identifiés pour la première fois chez S. virgaurea. Les tests biologiques sur les extraits et fractions ont par ailleurs mis en évidence des activités antioxydante, anti-tyrosinase et inhibitrice de cellules cancéreuses in vitro. Ces tests devront être approfondis ultérieurement

Contribution to the phytochemical study of Solidago virgaurea

Dans le but de valoriser la biodiversité végétale des Alpes-Maritimes, une plante commune dans cette région, Solidago virgaurea, a été sélectionnée pour son potentiel inhibiteur de la conversion levure-hyphe de Candida albicans, micro-organisme responsable d’infections bucco-dentaires de type candidose. Le fractionnement bioguidé de l’extrait aqueux a conduit à l’identification d’une famille de saponines particulièrement active. Parmi les onze saponines majoritaires caractérisées par RMN et HRMS, cinq se sont révélées être de nouvelles structures. Les tests biologiques ont néanmoins montré qu’elles n’étaient pas toutes actives contre la forme filamenteuse de C. albicans. Ces résultats ont conduit à une étude de la variabilité de la composition en saponines de plusieurs populations alpines de S. virgaurea. Trois méthodes de dosage des saponines ont été développées par HPLC et HPTLC. Les résultats ont démontré l'influence de différents facteurs sur la composition en saponines. Enfin, la composition globale de différents extraits de S. virgaurea a été étudiée dans le but d'identifier des activités biologiques complémentaires. Parmi les composés identifiés, trois nouveaux acides octulosoniques ont été caractérisés, aux côtés de trois composés phénoliques identifiés pour la première fois chez S. virgaurea. Les tests biologiques sur les extraits et fractions ont par ailleurs mis en évidence des activités antioxydante, anti-tyrosinase et inhibitrice de cellules cancéreuses in vitro. Ces tests devront être approfondis ultérieurement.Toward the promotion of plant diversity of Maritime Alps, a common plant of the alpine area, Solidago virgaurea, was chosen to its inhibiting activity of Candida albicans yeast-hyphal conversion, a causal agent of opportunistic oral infections named candidiasis. In a first step, an aqueous extract of S. virgaurea was submitted to bioassay guided fractionation. This led to an active saponin-containing fraction from which eleven saponins were characterized by carrying out NMR experiments along with HRMS analyses. Five out of these were identified for the first time and bioassays showed that saponins activity varied according to the molecular structure of the compound. In a second step, the saponins composition of various S. virgaurea populations was studied qualitatively and quantitatively, using HPLC and HPTLC. Results demonstrated that saponins composition depends on various factors. Finally, the overall chemical composition of different S. virgaurea extracts was investigated searching for additional bioactivities. Among all the identified compounds, three new octulosonic acids were characterized and three phenolic compounds were found for the first time in S. virgaurea. Moreover, bioassays on extracts and fractions showed antioxidant, anti-tyrosinase activity and inhibition of cancer cell lines in vitro. Further bioassays have now to be completed. As a conclusion, this work was the starting point of an oral care product development and the setting-up of an innovative sector

Triterpenoid saponins from the aerial parts of Solidago virgaurea alpestris with inhibiting activity of Candida albicans yeast-hyphal conversion

International audienceAs part of research for treatments to combat oral dryness, our evaluation of the activity of an aqueous extract of Solidago virgaurea (L.) ssp. alpestris (Asteraceae) revealed activity against Candida albicans hyphae, the pathogenic form of this yeast. Systematic bioassay-guided fractionation of this extract gave an active saponin-containing fraction from which six oleanane-type triterpenoid saponins were isolated. Three of these were isolated for the first time, as 3-O-(beta-D-glucopyranosyl-(1 -> 3)-beta-D-glucopyranosyl)-28-O-(beta-D-fucopyranosyl-(1 -> 2)-alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl-(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 2)-beta-D-xylopyranosyl)-polygalacic acid (virgaureasaponin 4), 3-O-(beta-D-glucopyranosyl)-28-O-(beta-D-fucopyranosyl-(1 -> 2)-alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl-(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 2)-beta-D-xylopyranosyl)-polygalacic acid (virgaureasaponin 5) and 3-O-(beta-D-glucopyranosyl)-28-O-(alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl-(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 2)-(5-O-acetylapiofuranosyl-(1 -> 3)-[4-O-(3-(3-hydroxy-1-oxobutoxy)-1-oxobutyl)]-beta-D-fucopyranosyl]-polygalacic acid (virgaureasaponin 6).Their structures were established by carrying out 1D and 2D NMR experiments along with HRMS analyses. All of the six saponins were evaluated to ascertain their inhibition of C albicans yeast-hyphal conversion, and four of them showed significant inhibition

Triterpenoid saponins from the aerial parts of Solidago virgaurea alpestris with inhibiting activity of Candida albicans yeast-hyphal conversion

International audienceAs part of research for treatments to combat oral dryness, our evaluation of the activity of an aqueous extract of Solidago virgaurea (L.) ssp. alpestris (Asteraceae) revealed activity against Candida albicans hyphae, the pathogenic form of this yeast. Systematic bioassay-guided fractionation of this extract gave an active saponin-containing fraction from which six oleanane-type triterpenoid saponins were isolated. Three of these were isolated for the first time, as 3-O-(beta-D-glucopyranosyl-(1 -> 3)-beta-D-glucopyranosyl)-28-O-(beta-D-fucopyranosyl-(1 -> 2)-alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl-(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 2)-beta-D-xylopyranosyl)-polygalacic acid (virgaureasaponin 4), 3-O-(beta-D-glucopyranosyl)-28-O-(beta-D-fucopyranosyl-(1 -> 2)-alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl-(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 2)-beta-D-xylopyranosyl)-polygalacic acid (virgaureasaponin 5) and 3-O-(beta-D-glucopyranosyl)-28-O-(alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl-(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 2)-(5-O-acetylapiofuranosyl-(1 -> 3)-[4-O-(3-(3-hydroxy-1-oxobutoxy)-1-oxobutyl)]-beta-D-fucopyranosyl]-polygalacic acid (virgaureasaponin 6).Their structures were established by carrying out 1D and 2D NMR experiments along with HRMS analyses. All of the six saponins were evaluated to ascertain their inhibition of C albicans yeast-hyphal conversion, and four of them showed significant inhibition