Chemical Constituents And Antifungal Activity Of Bamboo Leaves Of Bambusa Textilis McClure

Bambusa textilis McClure is one of very economical bamboo species, flourishin warmhumid climates, widely distributed in Guangdong，Zhejiang and Jiangxi province. Some literatures showed that the extraction of Bambusa textilis McClure leaves show good antibacterial，antifungal, antioxidant and inhibit weed growth ability. In order to further research and development of this resource, the extracts of Bambusa textilis McClure leaves were isolated by column chromatography on macroporous resin (AB-8), Polyamide, Sephadex LH-20, Prep HPLC and their structures were elucidated by the analysis of spectral data and physiochemical properties. The bioactivities of four compounds isolated from the extracts were evaluated by bioassay against Fusarium graminearum, Colletotrichum gloeosprioides and Botrytis cinerea. The synergism of hydrophilic, hydrophobic nano-SiO2and chitosan to selected chemical fungicides and isolated compounds were assessed. The main results were summarized as following:1. Twelve compounds were isolated from the extracts of Bambusa textilis McClure leaves by column chromatography on macroporous resin (AB-8), Polyamide, Sephadex LH-20, and Prep HPLC. And they were elucidated as p-Hydroxybenzaldehyde(1), Orientin(2), Isoorientin(3),Vitexin(4), Isovitexin(5), Tricin(6), p-Coumaric acid(7), Isovitexin-2’’-rhamnoside(8),Isovitexin-2’’-xylopyranoside(9),Apigenin-6-C-boivinose-7-O-glucopyranose(10),Apigenin-7-O-glucopyranos(11),Tricin-4’-O-glucopyranose(12) by the analysis of spectral data and physiochemical properties. Compounds8,9,10,11,12are isolated from Bambusa textilis McClure for the first time.2. The antifungal activity of four compounds isolated from the bamboo leaves against Fusarium graminearum,Colletotrichum gloeosprioides and Botrytis cinerea were evaluated. Orientin and Isovitexin-2’’-rhamnoside were exhibited excellent antifungal activity.The toxicity of Orientin against Fusarium graminearum,Colletotrichum gloeosprioides and Botrytis cinerea were1803.17mg/L、2185.33mg/L、1535.49mg/L and Isovitexin-2’’-rhamnoside were1792.42mg/L、2373.56mg/L、1661.80mg/L based on EC50.3. The synergism of hydrophilic, hydrophobic nano-SiO2and chitosan to selected chemical fungicides and isolated compounds were screened. The results showed that hydrophilic and hydrophobic nano-SiO2had little antifungal activity, but chitosan exhibited a little antifungal activity on Fusarium graminearum. The combination of Chitosan and Propiconazole has been proved promoting effect on Fusarium graminearum in five different ratio. Synergistic action of Chitosan on two isolated compounds has been found. The CTCs of the combinations were93.11and85.09for p-Hydroxybenzaldehyde/Chitosan and p-Coumaric acid/Chitosan respectively, at the ratio of17172.4ppm:1681.29ppm and13442.6ppm:1681.29ppm,based on EC50. Other remained combinations exhibited antogonisitic effect.