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ObjectiveTo explore the pretreatment methods to promote the enzymatic digestion and extraction of active ingredients from Magnoliae Officinalis Cortex dregs（MOCD）， and to provide a reference basis for the utilization of resource components in MOCD. MethodLiquid chromatography-mass spectrometry（LC-MS） was used for qualitative analysis of resource components in MOCD with an Agilent C18 reversed-phase column（3.0 mm×100 mm， 2.7 µm） at the flow rate of 0.4 mL·min-1， the mobile phase was water（A）-acetonitrile（B） for gradient elution（0-3 min， 25%-48%B； 3-6 min， 48%-59%B； 6-10 min， 59%-80%B； 10-20 min， 80%-90%B； 20-25 min， 90%B）， electrospray ionization（ESI） was employed with negative ion mode scanning and scanning range of m/z 50-1 200. A high performance liquid chromatography（HPLC）， which refered to the determination in the 2020 edition of Chinese Pharmacopoeia， was used for quantitative analysis of resource components in MOCD. Four kinds of pretreatment agents were used to separate the resource components from MOCD， and the mechanism of different pretreatment agents was investigated by field emission scanning electron microscopy（FESEM）， X-ray powder diffraction（XRD） and Fourier transform infrared spectroscopy（FT-IR）. ResultMagnolol， honokiol and lignocellulose were identified as the main resource components of MOCD by qualitative and quantitative analysis. Under the conditions of 1% NaOH， reaction temperature at 80 ℃ and reaction time of 60 min， the concentration of reducing sugar produced by the enzymatic hydrolysis was 32.18 g·L-1， which was 79.8% higher than that of the untreated MOCD. After adding tween-80， the enzymatic hydrolysis time was reduced to 1/3 of the original time， the concentration of reducing sugar was increased by 102.0%. And the total recovery of magnolol and honokiol in the pretreatment solution was 69.23%. ConclusionMagnolol， honokiol and lignocellulosic components in MOCD are valuable for development and utilization， the combination of alkaline pretreatment and tween-80 can realize the recovery and utilization of these three resource components， which can provide a new idea for comprehensive utilization of resource components in MOCD.
RESUMO
Background: Pretreatment of lignocellulosic biomass is essential for using it as a raw material for chemical and biofuel production. This study evaluates the effects of variables in the chemical pretreatment of the Arundo biomass on the glucose and xylose concentrations in the final enzymatic hydrolysate. Three pretreatments were tested: acid pretreatment, acid pretreatment followed by alkaline pretreatment, and alkaline pretreatment. Results: The amounts of glucose and xylose released by the enzymatic hydrolysis of the Arundo biomass obtained from acid pretreatment ranged from 6.2 to 19.1 g/L and 1.8 to 3.1 g/L, respectively. The addition of alkaline pretreatment led to a higher yield from the enzymatic hydrolysis, with the average glucose concentration 3.5 times that obtained after biomass hydrolysis with an acid pretreatment exclusively. The use of an alkaline pretreatment alone resulted in glucose and xylose concentrations similar to those obtained in the two-step pretreatment: acid pretreatment followed by alkaline pretreatment. There was no significant difference in 5-hydroxymethylfurfural, furfural, or acetic acid concentrations among the pretreatments. Conclusion: Alkaline pretreatment was essential for obtaining high concentrations of glucose and xylose. The application of an alkaline pretreatment alone resulted in high glucose and xylose concentrations. This result is very significant as it allows a cost reduction by eliminating one step.