Natural indigo, as one of the oldest dyes, is also a pivotal dye utilized in cotton fabrics today. A diversity of plants rich in indigo compounds belong to traditional Chinese herbal medicines. Indigo compounds have a variety of biological and pharmacological activities, including anticonvulsant, antibacterial, antifungal, antiviral and anticancer activities. A substantial progress in indigo biosynthesis has been made lately. This paper summarizes the value of indigo from the aspects of cultural history, biosynthetic pathways and the medicinal activities of its related derivatives involved in the pathways. In addition, the latest research advancements in indigo biosynthetic pathways is demonstrated in this paper, which would lay the theoretical foundation for the exploration and utilization of natural indigo.
Biosynthetic Pathways ; Coloring Agents ; Indigo Carmine/metabolism* ; Indigofera/metabolism*

Accessed to literatures at home and abroad, we introduced the process of indigo naturalis transforming from dyestuff industry into pharmaceutical industry. It is affirmed that the precursors of indigo and indirubin are isatan A, isatan B, isatan C and indicant. Meanwhile, author clarified the mechanism of transformation for these precursors transforming into indigo and indirubin. And we summarized methods of determination for these precursors. In summary, these references provide us accordance of study on processing principle of Indigo naturalis, and lay the foundation for technics of making indigo and indirubin entering into modern industry.
Indigo Carmine ; Indoles ; chemistry ; metabolism ; Oxidation-Reduction ; Pigmentation ; Plants ; metabolism ; Temperature

Indigo and indigo-like pigments are widely used in the industry of textile, food and medicine. Now people pays more and more attention to developing an alternative method of indigo production which is "environment-friendy", especially microbial biosynthesis of indigo. Many microorganisms involved in the biosynthesis of indigo have been isolated and characterized, and monooxygenase and dioxygenase have been identified to catalyze indigo biosynthesis. Some genes encoding for these enzymes have been cloned and used to construct "engineering bacteria". With this kind of bacteria, more efficient fermentation systems for indigo production have been exploited. In the meantime, biotransformation of the indigo produced by microorganisms has been under investigation. These progresses will bring us a greener method of indigo and indigo-like pigments production.
Biotechnology ; Coloring Agents ; metabolism ; Dioxygenases ; metabolism ; Fermentation ; Indigo Carmine ; Indoles ; metabolism ; Mixed Function Oxygenases ; metabolism ; Pseudomonas ; metabolism ; Sphingomonas ; metabolism

Different harvest times of Isatidis Folium had a significant effect on the yield and the quality of Isatidis Radix and Isatidis Folium. The harvest could increase the yield of Isatidis Folium, but reduce the yield of Isatidis Radix, the quality of Isatidis Radix and Isatidis Folium. One, two and three harvests of the Isatidis Folium reduced the yield of Isatidis Radix as 18.3%, 58.6%, 67.4% and increased the yield of the Folium as 107.3%, 86.3% and 116.6%. Ethanol-soluble extract of Isatidis Radix was 42.50%, 42.24%, 31.77%, which were 1.19%, 1.79%, 26.13% lower than those of the control, respectively. The water-soluble extract, indirubin, indigo content reduced with increase of the harvest times. Indirubin contents with two or three times harvests were higher than that of the control, but the content of water-soluble extract, ethanol-soluble extract, indigo were lower than those of the control.
Agriculture ; methods ; Desert Climate ; Drugs, Chinese Herbal ; chemistry ; metabolism ; Indigo Carmine ; Indoles ; metabolism ; Isatis ; metabolism ; Plant Leaves ; chemistry ; metabolism ; Plant Roots ; chemistry ; metabolism ; Quality Control ; Time Factors

The phenylacetone monooxygenase, isolated from Thermobifida fusca, mainly catalyzes Baeyer-Villiger oxidation reaction towards aromatic compounds. Met446 plays a vital role in catalytic promiscuity, based on the structure and function of phenylacetone monooxygenase. Mutation in Met446 locus can offer enzyme new catalytic feature to activate C-H bond, oxidizing indole to finally generate indigo and indirubin, but the yield was only 1.89 mg/L. In order to further improve the biosynthesis efficiency of the whole-cell catalyst, metabolic engineering was applied to change glucose metabolism pathway of Escherichia coli. Blocking glucose isomerase gene pgi led to pentose phosphate pathway instead of the glycolytic pathway to become the major metabolic pathways of glucose, which provided more cofactor NADPH needed in enzymatic oxidation of indole. Engineering the host E. coli led to synthesis of indigo and indirubin efficiency further increased to 25 mg/L. Combination of protein and metabolic engineering to design efficient whole-cell catalysts not only improves the synthesis of indigo and indirubin, but also provides a novel strategy for whole-cell catalyst development.
Escherichia coli ; genetics ; metabolism ; Glucose ; metabolism ; Indigo Carmine ; metabolism ; Indoles ; metabolism ; Industrial Microbiology ; methods ; Metabolic Engineering ; Metabolic Networks and Pathways ; Protein Engineering

OBJECTIVETo screen the factors that affect indirubin-generated significantly in the process of preparing indigo naturalis, optimize level combination and determine the optimum technology for indirubin-generated.

METHODUsing concentration of indirubin (mg x g(-1)) that generated by fresh leaf as an index, Plackett-Burman design, Box-Behnken design response surface analysis as the statistical method, we screened the significantly influencing factors and the optimal level combination.

RESULTThe soaking and making indirubin process in preparing indigo naturalis was identified as the wax is not removed before immersion with immersion pH 7, solvent volume-leaf weight (mL: g)15, soaked not avoided light, soaking 48 h, temperature 60 degrees C, ventilation time of 180 min, and added ammonia water to adjust pH to 10.5.

CONCLUSIONThe soaking and making indirubin process in preparing indigo naturalis is optimized systematically. It clarify the various factors on the impact of the active ingredient indirubin which controlled by industrialized production become reality in the process of preparing indigo naturalis, at the same time, it lay the foundation for processing principle of indigo naturalis.

Control Groups ; Dose-Response Relationship, Drug ; Hydrogen-Ion Concentration ; Indigo Carmine ; Indigofera ; chemistry ; Indoles ; chemical synthesis ; chemistry ; isolation & purification ; metabolism ; Myanmar ; Plant Leaves ; chemistry