Lignocellulose is the most abundant renewable organic carbon resource on earth. However, due to its complex structure, it must undergo a series of pretreatment processes before it can be efficiently utilized by microorganisms. The pretreatment process inevitably generates typical inhibitors such as furan aldehydes that seriously hinder the growth of microorganisms and the subsequent fermentation process. It is an important research field for bio-refining to recognize and clarify the furan aldehydes metabolic pathway of microorganisms and further develop microbial strains with strong tolerance and transformation ability towards these inhibitors. This article reviews the sources of furan aldehyde inhibitors, the inhibition mechanism of furan aldehydes on microorganisms, the furan aldehydes degradation pathways in microorganisms, and particularly focuses on the research progress of using biotechnological strategies to degrade furan aldehyde inhibitors. The main technical methods include traditional adaptive evolution engineering and metabolic engineering, and the emerging microbial co-cultivation systems as well as functional materials assisted microorganisms to remove furan aldehydes.
Aldehydes ; Fermentation ; Furans ; Lignin/metabolism*

OBJECTIVETo study the influence of the quorum sensing inhibitor brominated furanone on Porphyromonas gingivalis (P. gingivalis) biofilm formation.

METHODSDoubling dilution method was used to determine the minimal inhibition concentration (MIC) of brominated furanone on P. gingivalis. Absolute ethyl alcohol added in P. gingivalis bacterial suspension was used as the negative control, while P. gingivalis bacterial suspension as blank control. The influences of 1/4MIC, 1/2MIC, MIC, 2MIC of brominated furanone on P. gingivalis biofilm formation were studied by the optical density determination and scanning electron microscope (SEM).

RESULTSFour groups of brominated furanone with different concentrations were shown to inhibit P. gingivalis biofilm formation. With the increased concentration of brominated furanone, optical density of P. gingivalis suspension decreased. The biofilm structures of 1/4MIC group, 1/2MIC group and MIC group were loose. Only scattered P. gingivalis cells but no biofilm structure was seen in 2MIC group.

CONCLUSIONBrominated furanone could inhibit P. gingivalis biofilm formation without the influence on bacterial growth. The future application of this chemical compound may provide a new possibility for the antimicrobial treatment of periodontal disease.

Biofilms ; Furans ; Porphyromonas gingivalis ; Quorum Sensing

OBJECTIVETo develop an HPLC method for determination of clemastanin B which has anti-viral activity in Radix Isatidis and compare the contents of clemastanin B in the drugs from different origins.

METHODThe samples were separated on an ZORBAX SB-C18 (4.6 mm x 250 mm, 5 microm) column with the mobile phase of acetonitrile-water (11:89). Flow rate was 1.0 mL x min(-1). The detection wavelength was set at 225 nm. Column temperature was 30 degrees C.

RESULTThe linear range of clemastanin B was 0.0615-1.8441 microg (r = 0.9995), the average recovery was 97.74%, RSD was 1.4% (n=9). The contents of clemastanin B were in the range of 0.269-0.900 mg x g(-1) in Radix Isatidis from different origins.

CONCLUSIONThe method for quantitation of clemastanin B in Radix Isatidis was accurate and reliable, which can be used to evaluate the quality of Radix Isatidis.

China ; Furans ; analysis ; Isatis ; chemistry ; Plant Extracts ; analysis

Crassostrea sikamea (C.sikamea) is an important edible and medicinal seafood in China. In the present study, a compound named flazin was separated and identified from the ethyl acetate extract of C.sikamea (EAECs) for the first time. In addition, the 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetra zolium (MTS) assay revealed that EAECs and flazin inhibited the transformation of splenic lymphocytes in vitro. Moreover, flazin (20 μg·mL
Animals ; Carbolines ; Crassostrea ; Furans ; Lymphocytes ; Rats ; Rats, Sprague-Dawley ; Spleen

OBJECTIVETo investigate the effects of endophytic fungal elicitors on the growth and atractylodin accumulation of cell suspension cultures of Atractylodes lancea.

METHODThe endophytic fungal elicitors were added to the medium with different concentrations and culture period. Their effects on biomass, atractylodin content and relevant enzyme activities in suspension cultured cells were studied.

RESULTThe cell growth was not affected by elicitors at low concentration and obviously inhibited at high concentration. Inhibition rate reached 46.7% by 100 mg L(-1) elicitor. In addition, six strains from A. lancea, among which Rhizoctonia SP1 activity was higher, had distinctly promoted the accumulation of atractylodin. Atractylodin biosynthesis was notably promoted by 20-60 mg L(-1) Rhizoctonia SP1 elicitor. When 40 mg L(-1) Rhizoctonia SP1 elicitor was added in the medium at the 12 day, the maximum content of atractylodin was 28.06 microg L(-1) at the 21 day with 48.3% higher than that of the control and PPO, POD and CAT activities remarkably increased.

CONCLUSIONAdding the endophytic elicitors to the medium is able to be effective approaches to enhance atractylodin yield in the suspension culture cell of A. lancea.

Atractylodes ; growth & development ; microbiology ; physiology ; Cell Culture Techniques ; Cells, Cultured ; Fungi ; physiology ; Furans ; metabolism ; Symbiosis

Air ; analysis ; Chromatography, Gas ; methods ; Ethylene Oxide ; analysis ; Furans ; analysis ; Methylene Chloride ; analysis ; Workplace

OBJECTIVETo study the chemical constituents from Lobelia chinensis.

METHODThe constituents were extracted with 95% EtOH, partitioned with different solvents, and isolated and purified by silica gel column chromatography and crystallization, their structures were elucidated by physico-chemical properties and spectroscopic data.

RESULTSeven compounds were isolated from the titled plant. They were identified as 5-hydroxy-4'-methoxyflavone-7-O-rutinoside (1), n-butyl-O-beta-D-fructopyranoside (2), 5,7-dimethoxycoumarin (3), cirsiumaldehyde (4), diosmetin (5), 5-hydroxymethyl-2-furancarboxaldehyde (6), and 6-hydroxy-7-methoxycoumarin (7).

CONCLUSIONCompounds 2-4, 6, and 7 were obtained from the titled plant for the first time.

Coumarins ; analysis ; Furans ; analysis ; Lobelia ; chemistry ; Plant Extracts ; chemistry ; isolation & purification

Carnosine (beta-Ala-L-His) has high antioxidant activity, and it is widely used in biology, chemical engineering, medicine and other fields. Its analogue syntheised in non-aqueous solvent and catalyzed by enzymes is high-effective but low-price, so it has great prospect. Here, we synthesized a carnosine analogue imidazole 4(5)-alanylamide-5(4)-carboxylic acid with imidazole-4,5-dicarboxylic acid and L-Alanine as substrates, alpha-chymotrypsin as catalyst in tetrahydrofuran (THF) solvent. Based on the orthogonal experiments, the optimized synthetic conditions are 4,5-dicarboxylic acid: L-alanine = 1:3 (m/m), alpha-chymotrypsin: substrates (4,5-dicarboxyl acid and L-alanine) = 1:200 (m/m), pH 8 phosphate buffer:THF = 1.6:10 (V/V), reaction temperature 35 degrees C, time 1.5 h. We separated the product with silica gel G60 thin-layer chromatography (TLC), and a new spot appeared at Rf (ratio to front) = 0.81; then the new spot was purified and characterized with UV spectra, high performance liquid chromatogram (HPLC) and 13C NMR (13C nuclear magnetic resonance). The UV spectra shows a new absorption peak at 310 nm, and the peak in 253 nm is largely strengthened; HPLC reserve times are all 4.5 min at 253 nm, 310 nm, 330 nm; 13C NMR shows 8 carbons. Combing with the catalytic mechanism of alpha-chymotrypsin, structure of the analogue is confirmed, i.e., imidazole 4(5)-alanylamide-5(4)-carboxylic acid.
Carnosine ; analogs & derivatives ; biosynthesis ; chemistry ; Catalysis ; Chromatography, High Pressure Liquid ; Chymotrypsin ; metabolism ; Furans ; chemistry ; Solvents

OBJECTIVEHeadspace solid-phase microextraction (HS-SPME) was used pre-concentration procedure for the determination of tetrahydrofuran in urine by gas chromatography with hydrogen flame detector.

METHODSSeveral parameters controlling SPME was studied and optimised: SPME fiber, extraction time and extraction temperature, desorption time and desorption temperature.

RESULTSUnder optimal conditions, the correlation coefficient was 0.9998 and good recoveries (range from 93.0% ∼ 100.8%) were achieved, the detection limit was 0.5 µg/L.

CONCLUSIONThe method can be applied to the determination of trace amount of tetrahydrofuran in urine.

Chromatography, Gas ; methods ; Furans ; urine ; Humans ; Occupational Exposure ; analysis ; Solid Phase Microextraction ; methods

To study the chemical constituents from the leaves of Celastrus gemmatus Loes., chromatographic methods were used to isolate and purify the chemical constituents, their structures were elucidated by the physiochemical characteristics and spectral data. Nine compounds were obtained and identified as (-)-massoniresinol 3a-O-beta-D-glucopyranoside (1), ambrosidine (2), isolariciresinol 9-O-beta-D-glucopyranoside (3), kaempferol 3-O-beta-D-glucopyranoside (astragalin) (4), kaempferol 3-O-rutinoside (5), kaempferol 3-O-neohesperidoside (6), apigenin 7-O-beta-D-glucuronide (7), apigenin 7-O-beta-D-glucuronide methyl ester (8) and D-sorbitol (9). Compound 1 is a new compound, the others are isolated from this genus for the first time, and this is the first time to report lignan compounds from genus Celastrus.
Celastrus ; chemistry ; Furans ; chemistry ; isolation & purification ; Lignans ; chemistry ; isolation & purification ; Plant Leaves ; chemistry