ABSTRACT
Direct acid hydrolysis of Dioscorea zingiberensis rhizomes for preparation of diosgenin is wildly used in the traditional industry， which uses a large amount of inorganic acid catalysts， with high wastewater discharge and serious environmental pollution. Therefore， exploring clean and efficient preparation methods and processes has become an inevitable choice to realize the sustainable development of industrial production of diosgenin. Herein， the author reviewed and analyzed the research progress and problems of enzymatic hydrolysis， microbial transformation and modified acid hydrolysis in the preparation of diosgenin from D. zingiberensis rhizomes during the last ten years， and their application prospects are analyzed. Enzymatic hydrolysis has mild reaction conditions， but the yield of diosgenin is low， the economic cost is high， and the purification process of active enzyme is complicated. Microorganism shows specific activity to the substrate and high efficiency for diosgenin production， and microbial transformation is clean and environmentally friendly， but microbial transformation is time-consuming and the metabolic intermediates are complicated. For the modified acid hydrolysis， two-phase acid hydrolysis can reduce the amount of acid catalyst， and sulfonic acid-functionalized ionic liquid displays good recyclable performance by replacing the traditional inorganic acid， however， the wastewater discharge should still be considered. Solid acid catalysts are non-corrosive and easy to be recycled， but the need to use ethanol as the reaction solvent has certain safety hazards， and the catalyst preparation process is cumbersome. In conclusion， exploring clean and efficient conversion methods is an important research trend for preparation of diosgenin from D. zingiberensis rhizomes. For the enzymatic hydrolysis， the key glycoside hydrolases in the bioconversion process should be explored in depth， the conversion pathway of enzymatic saponins and enzyme specificity should be fully elucidated， and efforts should be made to improve the efficiency of enzymatic hydrolysis. For the microbial transformation， we should accelerate its industrial application process based on selecting and breeding efficient transformation strains， and optimizing stable transformation systems and processes， and in-depth investigation of the mechanism of microbial transformation， fully elucidating the specific key hydrolases and its catalytic properties， and striving to improve the efficiency of microbial transformation. For the modified acid hydrolysis， novel acid catalytic system with simple structure， stable performance and good biodegradability should be explored and applied， which can effectively solve the problems of environmental pollution and production safety.
ABSTRACT
Microbial transformation is an efficient enzymatic approach for the structural modification of exogenous compounds to obtain derivatives. Compared with traditional chemical synthesis, the microbial transformation has in fact the undoubtable advantages of strong region-and stereo-selectivity, and a low environmental and economic impact on the production process, which can achieve the reactions challenging to chemical synthesis. Because microbes are equipped with a broad-spectrum of enzymes and therefore can metabolize various substrates, they are not only a significant route for obtaining novel active derivatives, but also an effective tool for mimicking mammal metabolism in vitro. Artemisinin, a sesquiterpene with a peroxy-bridged structure serving as the main active functional group, is a famous antimalarial agent discovered from Artemisia annua L. Some sesquiterpenoids, such as dihydroartemisinin, artemether, and arteether, have been developed on the basis of artemisinin, which have been successfully marketed and become the first-line antimalarial drugs recommended by WHO. As revealed by pharmacological studies, artemisinin and its derivatives have exhibited extensive biological activities, including antimalarial, antitumor, antiviral, anti-inflammatory, and immunomodulatory. As an efficient approach for structural modification, microbial transformation of artemisinin and its derivatives is an increasingly popular strategy that attracts considerable attention recently, and numerous novel derivatives have been discovered. Herein, this paper reviewed the microbial transformation of artemisinin and its artemisinin, including microbial strains, culture conditions, product isolation and yield, and biological activities, and summarized the advances in microbial transformation in obtaining active derivatives of artemisinin and the simulation of in vivo metabolism of drugs.
Subject(s)
Animals , Antimalarials/pharmacology , Antiviral Agents , Artemether , Artemisinins , MammalsABSTRACT
Objective Asiatic acid is the main medicinal component of aursane pentacyclic triterpene and possessed various biological activities. In order to obtain better active Asiatic acid analogues, microbial transformation was used for structural modification. Methods Asiatic acid was biotransformed by Syncephalum racemosum CGMCC 3.2500. The structure of the compound was identified by high resolution electrospray ionization mass spectroscopy (HR-ESI-MS) and nuclear magnetic resonance spectroscopy (i.e., 1H NMR、13C NMR、1H-13C HSQC、1H-13C HMBC、1H-1H NOESY). Results The structure of the compound was determined as 2-oxo-3α, 15α, 23-trihydroxyurs-12-en-28-oic acid which was a new compound. Conclusion Syncephalum racemosum CGMCC 3.2500 can modify the structure of Asiatic acid and obtain Asiatic acid analogues.
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Gastrodin is a major active ingredient in Gastrodia elata, which is one of the traditional rare medicinal herbs in China. It has lots of pharmacological activities, such as reducing blood pressure, anti-epileptic, anti-tumor, and protecting nerve, etc. With the increasing demand for gastrodin in the market and the inherent problems of traditional methods on obtaining gastrodin, new methods are urgently needed to solve various difficulties in the actual production of gastrodin. Biosynthesis is a new method instead of the traditional acquisition method, and has made great progress and achievements in gastrodin acquisition. Therefore, it is necessary to systematically review the biosynthesis of gastrodin from three aspects of biosynthetic pathway, plant transformation and microbial transformation in this paper, hoping to provide valuable reference for further improvement and perfection of gastrodin production method in the future to meet public increasing demand for gastrodin.
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Active components of Chinese materia medica (CMM) are the material basis of its efficacy and the keys to realize modernization of CMM. How to improve the content of active ingredients of CMM has become a research hotspot, and microbial transformation is one of its key technologies. The practice has proved that the strains are different, the types of CMM are different, and the transformation effects are different. Therefore, the research on fungal transformation of CMM active ingredients such as terpenes, alkaloids, phenylpropanoids, quinones, steroids, organic acids, etc. is reviewed in this study.
ABSTRACT
Glycosides are the active ingredients (AIs) of many Chinese herbs and have become hot spots along with the findings of their new functions,such as anti-inflammatory,antivirus,enhanced immunity and anti-cancer.It has been found that glycosides exert their effects by converting to aglycons or other AIs in vivo.Therefore,the transformation of glycosides to the corresponding AIs in vitro becomes very important to enhance their bioavailabilities.The microbial transformation has an unparalleled advantage in the transformation of Chinese herbs in vitro for its reaction specificity,less by-products,mild reaction conditions and environmental protection.This paper summarized and prospected researches of glycosides' microbial transformation.
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OBJECTIVE:To optimize the conditions of extractive microbial transformation for producing L-phenylacetylcarbi-nol(L-PAC). METHODS:HPLC was used to determine the concentration of L-PAC,which was extracted by saccharmyces cerevi-siae. Using L-PAC concentration as response value,Box-Behnken response surface design was adopted to investigate the 3 main fac-tors of benzaldehyde,Triton X-100 and glucose dose,and verification test was conducted. RESULTS:The interaction between benzaldehyde and Triton X-100 was the most significant. The optimized combination was as follows as benzaldehyde of 1.1%,Tri-ton X-100 of 0.14 g/mL,glucose of 0.028 g/mL. The average concentration in verification test of L-PAC was 28.04 mmol/L (RSD=1.35%,n=3),showing 0.11% relative error with the predicted value of 28.01 mmol/L. CONCLUSIONS:Response sur-face method has optimized the conditions of extractive microbial transformation for producing L-PAC,obtained optimal combina-tion of each factor,and provided favorable reference for volume-producing L-PAC.
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Microbial transformation of (±)-6-(1,1-dimethylallyl)naringenin (6-DMAN, 1) and (±)-5-(O-prenyl) naringenin-4′,7-diacetate (5-O-PN, 2) was performed by using fungi. Scale-up fermentation studies with Mucor hiemalis, Cunninghamella elegans var. elegans, and Penicillium chrysogenum led to the isolation of five microbial metabolites. Chemical structures of the metabolites were determined by spectral analyses as (±)-8-prenylnaringenin (3), (2S)-5,4′-dihydroxy-7,8-[(R)-2-(1-hydroxy-1-methylethyl)-2,3-dihydrofurano]flavanone (4), (±)-5-(O-prenyl)naringenin-4′-acetate (5), (±)-naringenin-4′-acetate (6), and (±)-naringenin (7), of which 5 was identified as a new compound.
Subject(s)
Cunninghamella , Fermentation , Fungi , Mucor , Penicillium chrysogenumABSTRACT
The regio- and stereo-selective hydroxylations of two ingenane diterpenoids, 20-deoxyingenol (1) and 13-oxyingenol dodecanoat (2), by the filamentous fungi Mortierella ramanniana and Gibberella fujikuroi were investigated in the present study. Four undescribed metabolites (3-6) of substrate 1 and two undescribed metabolites (7 and 8) of substrate 2 were isolated. All the metabolites were identified as hydroxylated ingenane derivatives by extensive NMR and HR-ESI-MS data analyses. All the biotransformed compounds and the substrates were evaluated for their cytotoxicities against three human cancer cell lines, including human colon cancer Caco-2, breast cancer MCF-7, and adriamycin (ADM)-resistant MCF-7/ADM cell lines. All ingenane alcohols (1, and 3-6) displayed no significant cytotoxic activities. The substrate 13-oxyingenol dodecanoat (2) showed moderate cytotoxicity with IC values being 35.59 ± 5.37 μmol·L (Caco-2), 24.04 ± 4.70 μmol·L (MCF-7), and 22.24 ± 5.19 μmol·L (MCF-7/ADM). However, metabolites 7 and 8 displayed no significant cytotoxicity. These results indicated that the hydroxylation at the C-13 aliphatic acid ester of substrate 2 can significantly reduce the cytotoxic activity.
Subject(s)
Humans , Antineoplastic Agents , Chemistry , Metabolism , Biotransformation , Cell Line, Tumor , Diterpenes , Chemistry , Metabolism , Gibberella , Metabolism , Hydroxylation , Molecular Structure , Mortierella , Metabolism , StereoisomerismABSTRACT
The microbial transformation of anthranilic acid (1) by the marine-mudflat-derived fungus Thielavia sp. produced an antibacterial polycyclic quinazoline alkaloid, thielaviazoline (2). The stereostructure of the metabolite was assigned based on detailed spectroscopic data analyses including comparison of the NMR (¹H and ¹³C) data with those of reported compound (2). Compound 2 displayed in vitro antimicrobial activity against methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA), with minimum inhibitory concentrations (MICs) of 6.25 and 12.5 µg/mL, respectively. Compound 2 also showed potent radical-scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) with an IC₅₀ of 11 µM, which was more active than the positive control, L-ascorbic acid (IC₅₀, 20.0 µM).
Subject(s)
Ascorbic Acid , Fungi , In Vitro Techniques , Methicillin Resistance , Microbial Sensitivity Tests , Staphylococcus aureus , Statistics as TopicABSTRACT
OBJECTIVE: To determine the content of calcifediol in microbial transformation broth of VD3 quickly and accurately. METHODS: The separation was performed on an Elite Hypersil C18 column (4.6 mm × 250 mm, 5 μm) with acetonitrile-water (85:15) as the mobile phase eluted at a flow rate of 2.0 mL · min-1. The column temperature was maintained at 50℃. External standard method was adopted using the peak area at 265 nm for determination. RESULTS: A good linear relationship was obtained in the range of 10.1 -2 020 μg · mL-1 (r =0.999 9), the limit of quantitation was 0.6 ng, the limit of detection was 0.3 ng, and the average recovery rate was 101.06% (RSD 1.44%, n=9). CONCLUSION: The established RP-HPLC method could meet the request of content determination of calcifediol in VD3 microbial transformation broth in industrial production.
ABSTRACT
In the present research, the steroidal anti-asthmatic drug beclomethasone dipropionate was subjected to microbial biotransformation by Aspergillus niger. Beclomethasone dipropionate was transformed into various metabolites first time from microbial transformation. New drug metabolites produced can act as new potential drug molecules and can replace the old drugs in terms of safety, efficacy, and least resistance. They were purified by preparative thin layer chromatography technique, and their structures were elucidated using modern spectroscopic techniques, such as 13C NMR, 1H NMR, HMQC, HMQC, COSY, and NOESY, and mass spectrometry, such as EI-MS. Four metabolites were purified: (i) beclomethasone 17-monopropionate, (ii) beclomethasone 21-monopropionate, (iii) beclomethasone, and (iv) 9beta,11beta-epoxy-17,21-dihydroxy-16beta-methylpregna-1,4-diene-3,20-dione 21-propionate.
Na pesquisa presente o fármaco esteróide antiasmático dipropionato de beclometasona foi submetido à biotransformação microbiana pelo Aspergillus niger. O dipropionato de beclometasona foi transformado, pela primeira vez, em metabólitos variados por biotransformação microbiana. Novos metabólitos do fármaco produzidos podem agir como novas moléculas potenciais e podem substituir os fármacos antigos em questão de segurança, eficácia e mínima resistência. Eles foram purificados por cromatografia em camada delgada preparativa e as suas estruturas foram elucidadas usando técnicas espectroscópicas modernas, como 13C NMR, 1H NMR; HMQC; HMQC; COSY, NOESY e espectrometria de massas, por exemplo, EI-MS. Purificaram-se quatro metabólitos, denominados (i) 17-monopropionato de beclometasona; (ii) 21-monopropionato de beclometasona: (iii) beclometasona e (iv) 21-propionato de 9beta,11beta-epoxi-17,21-diidroxi-16beta-metilpregna-1,4-dieno-3,20-diona.
Subject(s)
Aspergillus niger/classification , Beclomethasone/pharmacology , BiotransformationABSTRACT
Objective: To study the microbial transformation of ursolic acid using Penicillium melinii. Methods: Ursolic acid was put into the fluid medium inoculated with fungius (P. melinii AS3.4774) and cultured in the shaker at 28 °C and 140 r/min for 5 d. The crude extract was separated by chromatography. The structures of transformed products were elucidated based on the extentive NMR studies. Results: Ursolic acid was transformed by P. melinii AS3.4774 and three major derivatives were isolated and elucidated. They were 3-carbonyl ursolic acid, ursolic acid-28-O-β-D-glucopyranosyl ester, and ursolic acid-3-O-β-D-glucopyranoside. Conclusion: It is the first time that the three major derivatives could be microbial synthesized from ursolic acid by P. melinii AS3.4774.
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Objective: To study the microbial transformation of ursolic acid by Penicillium adametzi. Methods: The biotransformed extract was obtained by co-culture of substrate (ursolic acid) and the transferring fungi in a liquid medium at certain conditions, and then the inocula were dealt in an ultrasonic bath and extracted with n-BuOH. The transformed extract was isolated by chromatography on macroporous resin column, silica gel column, and preparative HPLC. The structures of the isolated compounds were identified by spectral analyses, physical constants, and chemical evidences. Results: A microbial transformed product was isolated and identified as 3β, 21α-dihydroxyl-ursolic acid-28-O-β-D-glucopyranoside and it had the significant inhibitory effects against HepG2 cell with IC50 value of 19.72 μmol. Conclusion: The transformed product, 3β, 21α-dihydroxyl-ursolic acid-28-O-β-D-glucopyranoside, is a new compound with the stronger cytotoxic activity than that of substrate.
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Microbial transformation technology has been applied in the study of Chinese materia medica (CMM) widely. Photosynthetic bacteria biotransformation in the research of Chinese medicine pharmaceutics has become one of the focuses in the field of microbial transformation technology. In this paper, we summarized the pharmacological activity and pharmacodynamic material bases of CMM metabolized by photosynthetic bacteria, in addition, summarized the mechanism of photosynthetic bacteria biotransformation. We also pointed out the problems needed to be studied in the future.
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Based on the research methods and technologies of science of Chinese materia medica, chemistry and mi-crobiology, the resource material conversion of functional material, biomass energy, nutrients in castoff from Chinese materia medica industrialization is promoted by microbial transformation. This will help enhance the resource utiliza-tion value, extend resource industry chains, and realize Chinese materia medica resource industry with the best use of everything, resource-saving and environment-friendly recycling economy development.
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Objective: To enhance the transformation rate of brucine and strychnine in Strychnos nux-vomica and establish a high efficient microbial transformation system by Cunninghamella blakesleeana. Methods: Based on the growth and metabolic rule of C. blakesleeana, through single-factor experiments, by using brucine sulphate and strychnine nitrate as substrates and the transformation rate of each substrate as index, several influential factors were investigated. Results: The optimal transformation condition was inoculation amount at 4%, fermentation time at 2.5 d, substrate concentration at 20 mg/L, transformation time at 3 d, culture temperature at 28°C, initial pH of medium at 6.5, and shaking speed at 150 r/min. Under the above condition, the average transformation rates of brucine sulphate and strychnine nitrate were approximate 77.75% and 77.10%, respectively. Conclusion: The average transformation rates of brucine sulphate and strychnine nitrate are increased by about 17% and 22%, respectively by C. blakesleeana, and this microbial transformation system could meet the need of the study on "toxicity attenuation and efficacy reservation" of S. nux-vomica.
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Objective To apply the microbial transformation to transforming the total saponins in the fruit of Panax ginseng (SFPG) and preparing ginsenoside compound K (C-K). Methods The four microbial strains m14, m3, m8, and m9 were screened and isolated from the soil in the botanic garden planted for P. ginseng and they were used for the microbial transformation of SFPG to optimize the strains. Taking C-K contents as index the microbial transformation was detected and analyzed by TLC and HPLC. Results The strain m14 was found to transform the SFPG efficiently to C-K at first. The optimal culturing and transformation conditions of m14 were obtained: time, 6 d; temperature, 30 ℃; revolution of cradle, 160 r/min; initial pH value, 5.5; substratum concentration, 120 mg/mL. Under the optimal condition, the content of C-K was 41.65 times as much as before transformation by m14. Conclusion The m14 is the most effective strain among the four fungal strains. It is the new way available for the C-K industrialized production.
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Canrenone is an important intermediate for the synthesis of eplerenone,a cardiovascular drug.C_ 11 ?-hydroxylation of canrenone is the key reaction,which can be done by microbial transformation.Rhizopus sp.SIPI-0602,kept in our lab,could high selectively transform canrenone to a compound named SIPI-11.By determining and analyzing the MS,UV,NMR etc.spectra of compound SIPI-11,its chemical structure was elucidated to be 11?-hydroxycanrenone.The study on flask transformation technology showed that the transformation ratio exceeded 90% when the substrate concentration was not more than 6g/L.
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Microbial selective side-chain degradation of phytosterol,which can obtain the steroid medicine intermediate compounds-androst-4-ene-3,17-dione (4-AD) and androsta-1,4-diene-3,17-dione (ADD),has an important meaning to pharmacy. There is no systematic literature concerned in existence. Its mechnism,approaches,influencing factors and so on over these years were fully reviewed in the paper. The trend of development in the area is expanded.