Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan.
Molecules. 2013 Nov 21;18(11):14381-96. doi: 10.3390/molecules181114381.
Indigo naturalis is effective in treating nail psoriasis coexisting with microorganism infections. This study examines the antimicrobial effects of indigo naturalis prepared from Strobilanthes formosanus Moore. Eight bacterial and seven fungal strains were assayed using the agar diffusion method to examine the effects of indigo naturalis and its bioactive compounds. The bioactive compounds of indigo naturalis were purified sequentially using GFC, TLC, and HPLC. Their structures were identified using mass spectrometry and NMR spectroscopy. UPLC-MS/MS was applied to compare the metabolome profiles of indigo naturalis ethyl-acetate (EA) extract and its source plant, Strobilanthes formosanus Moore. The results of in vitro antimicrobial assays showed that indigo naturalis EA-extract significantly (≥1 mg/disc) inhibits Gram-positive bacteria (Staphylococcus aureus, S. epidermis and methicillin-resistant S. aureus (MRSA)) and mildly inhibits non-dermatophytic onychomycosis pathogens (Aspergillus fumigates and Candida albicans), but has little effect on dermatophyes. Isatin and tryptanthrin were identified as the bioactive compounds of indigo naturalis using S. aureus and S. epidermis as the bioassay model. Both bioactive ingredients had no effect on all tested fungi. In summary, indigo naturalis prepared from Strobilanthes formosanus Moore exhibits antimicrobial effects on Staphylococcus and non-dermatophytic onychomycosis pathogens. Tryptanthrin and isatin may be its major bioactive ingredients against Staphylococcus and the inhibitory effect on MRSA may be due to other unidentified ingredients.
天然靛蓝对治疗合并微生物感染的甲银屑病有效。本研究考察了用罗勒制备的天然靛蓝的抗菌作用。采用琼脂扩散法对 8 种细菌和 7 种真菌菌株进行了测定，以考察天然靛蓝及其生物活性化合物的作用。天然靛蓝的生物活性化合物依次用 GFC、TLC 和 HPLC 进行纯化。使用质谱和 NMR 光谱法鉴定其结构。采用 UPLC-MS/MS 比较天然靛蓝乙酯（EA）提取物及其生源植物罗勒的代谢组图谱。体外抗菌试验结果表明，天然靛蓝 EA 提取物对革兰氏阳性菌（金黄色葡萄球菌、表皮葡萄球菌和耐甲氧西林金黄色葡萄球菌（MRSA））有明显（≥1mg/disc）抑制作用，对非皮肤癣菌性甲真菌病病原体（烟曲霉和白色念珠菌）有轻微抑制作用，但对皮肤癣菌没有影响。以金黄色葡萄球菌和表皮葡萄球菌为生物测定模型，确定了靛蓝中的生物活性化合物为色胺酮和靛蓝酮。两种生物活性成分对所有测试的真菌均无影响。综上所述，罗勒制备的天然靛蓝对金黄色葡萄球菌和非皮肤癣菌性甲真菌病病原体具有抗菌作用。色胺酮和靛蓝酮可能是其抗金黄色葡萄球菌的主要生物活性成分，对 MRSA 的抑制作用可能是由于其他未鉴定的成分所致。
