Anti-fungal and anti-bacterial activities of ethanol extracts of selected traditional Chinese medicinal herbs

Objective:To evaluate in ritro antimicrobial activities of selected 58 ethno-medicinal plant extracts with a view to assess their therapeutic potential.Methods:A total of 58 traditional Chinese medicinal plants were carefully selected based on the literature review and their traditional use.The antimicrobial activities of ethanol extracts of these medicinal plants were tested against fungi(Aspergillus funigaius),yeast(Candida albicans),gram-negative(Acirelobacter haumannii and Pseudornnruis aeruginosa)and gram-positive bacteria(Staphglococcus aureus).The activities were tested at three different concentrations of 1.00,0.10 and 0.01 mg/mL.The data was analysed using Gene data Screener program.Results:The measured antimicrobial activities indicated that out of the 58 plant extracts,15 extracts showed anti-fungal activity and 23 extracts exhibited anti-bacterial activity.Eight plant extracts have exhibited both anti-bacterial and anti-fungal activities.For instance,Eucommia ulmoides,Pohgonum cuspidcrtum,Poria cocas and Uncaria rhineophylla showed activity against both bacterial and fungal strains,indicating their broad spectrum of activity.Conclusions:The results revealed that the ethanol extracts of 30 plants out of the selected 58 possess significant antimicrobial activities.It is interesting to note that the findings from the current study are consistent with the traditional use.A clear correlation has also been found between the antimicrobial activity and the flavonoid content of the plant extracts which is in agreement with the literature.Hence.the results presented here can be used to guide the selection of potential plant species for the isolation and structure elucidation of novel antimicrobial compounds in order to establish the structure-activity relationship.This in turn is expected to lead the way to the discovery of novel antimicrobial agents for therapeutic use.

Discovery of gargantulides B and C,new 52-membered macrolactones from Amycolatopsis sp.Complete absolute stereochemistry of the gargantulide family

Gargantulides B and C,two new and highly complex 52-membered glycosylated macrolactones,were isolated from Amycolatopsis sp.strain CA-230715 during an antibacterial screening campaign.The structures of these giant macrolides were elucidated by 2D NMR spectroscopy and shown to be related to gargantulide A,although containing additional β-glucopyranose and/orα-arabinofuranose monosaccharides separately attached to their backbones.Genome sequencing allowed the identification of a strikingly large 216 kbp biosynthetic gene cluster,among the largest type Ⅰ PKS clusters described so far,and the proposal of a previously unreported biosynthetic pathway for gargantulides A-C.The absolute configurations of gargantulides B and C were assigned based on a combination of NMR and bioinformatics analysis of ketoreductase and enoylreductase domains within the multimodular type Ⅰ PKS.In addition,the absolute stereochemistry of gargantulide A has now been revised and completed.Gargantulides B and C display potent antibacterial activity against a set of drug-resistant Gram-positive bacteria and moderate activity against the clinically relevant Gram-negative pathogen Acinetobacter baumannii.