Effects of Sample Processing on Natural Glycoside Composition—Tissue Disruption, Endogenous Enzymatic Transformation, Drying, and Pre-Extraction Treatment

Introduction

The chemical composition of natural products may continue to change after plant materials are harvested. Cutting and pulverization alter tissue integrity; moisture, temperature, and pH affect endogenous enzyme activity; and drying and heating can further alter enzymatic reactions, tissue structure, and the chemical stability of certain compounds. Samples introduced into high-performance liquid chromatography (HPLC) or liquid chromatography-mass spectrometry (LC-MS) systems have already undergone multiple stages, including harvesting, processing, and extraction.

Scutellaria baicalensis provides an experimental example. Changes in the moisture status, temperature, pH, treatment time, and solvent conditions applied to S. baicalensis powder before extraction can markedly alter the measured levels of baicalin, wogonoside, and their corresponding aglycones [1]. S. baicalensis roots also contain an endogenous β-D-glucuronidase (GUS) capable of hydrolyzing these flavonoid glucuronides [6]. Sample pretreatment is therefore an important factor determining the actual chemical composition present at the time of analysis.

1 Primary Glycosides, Secondary Glycosides, and Post-Harvest Changes in Chemical Composition

1.1 Traditional Meanings of Primary and Secondary Glycosides

In traditional pharmacognosy, the terms “primary glycosides” and “secondary glycosides” are used to describe transformation relationships among certain glycosides during storage, processing, or extraction. Some primary glycosides can undergo partial hydrolysis and lose part of their glycosyl moieties, thereby forming compounds traditionally classified as secondary glycosides. Classical studies of digitalis used the terms primary glycosides and secondary glycosides to describe this type of transformation occurring during storage [2].

These terms describe transformation relationships among specific glycosides. Plants can also synthesize compounds with different degrees of glycosylation through their own metabolic pathways. The actual origin of a particular glycoside in a sample therefore also depends on the plant’s metabolic pathways and its post-harvest processing history.

1.2 Number of Glycosyl Groups and Compound Origin

Amygdalin and prunasin differ in their degree of glycosylation. Studies of almond (Prunus dulcis) have shown that prunasin is itself a normal product of the plant’s cyanogenic glycoside metabolic pathway and can undergo further glycosylation to form amygdalin [3].

This demonstrates that natural products containing fewer glycosyl groups can arise directly from normal plant metabolism. Whether a compound detected during sample processing is formed through transformation of another glycoside can be determined from evidence such as quantitative changes before and after treatment, time-course data, relevant enzyme activity, and plant metabolic pathways.

2 Tissue Disruption and Endogenous Enzymatic Transformation

2.1 Spatial Constraints in Plant Tissues

Glycosides and their associated enzymes have specific tissue, cellular, or subcellular distributions within plant tissues. Such spatial organization affects substrate diffusion and the opportunities for enzymes and substrates to come into contact.

The glucosinolate-myrosinase system provides clear evidence of tissue-specific localization. Höglund et al. used immunocytochemical methods to study rapeseed (Brassica napus) and found that myrosinase was concentrated mainly in a small number of specialized cells, showing a distinctly nonuniform distribution within the tissue [4]. Glucosinolate-rich S-cells have also been identified in the flower stalks of Arabidopsis thaliana, with reported glucosinolate concentrations exceeding 100 mmol/L in these cells [5].

Patterns of spatial organization vary among plants and organs. They may involve selective distribution among different cell types or compartmentalization within individual cells. A common consequence is that tissue structure helps regulate the conditions under which enzymes, substrates, and other reaction components come into contact.

Cutting, pulverization, and grinding disrupt cellular and tissue structures while promoting the release of cellular contents and molecular diffusion. When fresh plant material retains relatively high endogenous enzyme activity, the extent of tissue disruption can directly affect the stability of glycosides before analysis.

2.2 Changes in Flavonoid Composition After Cutting and Pulverization of Scutellaria baicalensis

The roots of S. baicalensis contain baicalin, wogonoside, and their corresponding aglycones, baicalein and wogonin. Ikegami et al. purified a β-D-glucuronidase from S. baicalensis roots and demonstrated that the enzyme could hydrolyze baicalin and wogonin glucuronide, providing direct evidence for the endogenous enzymatic hydrolysis of glucuronides in S. baicalensis [6].

Bai et al. compared compositional changes in freshly cut S. baicalensis root slices with those in further pulverized fresh roots. Under room-temperature conditions with moisture maintained, baicalin in freshly pulverized samples decreased from 95.67 mg/g at 0 h to 5.04 mg/g at 22 h, while wogonoside decreased from 17.89 mg/g to 1.13 mg/g, corresponding to decreases of 94.7% and 93.7%, respectively. The corresponding glycosides in freshly cut samples also decreased over time, but to a lesser extent [7].

The two groups of materials originated from the same source and were maintained under similar temperature and moisture conditions, yet differences in the degree of tissue disruption were accompanied by markedly different rates of glycoside change. Pulverization increases the exposed tissue area while also altering cellular integrity, substrate release, and contact between endogenous enzymes and their substrates. The duration for which pulverized material is left standing can therefore be directly reflected in the final quantitative results for glycosides and aglycones.

3 Effects of Water, pH, and Extraction Solvents on Glycoside Composition

3.1 Aqueous Pretreatment Alters the Flavonoid Composition of Scutellaria baicalensis

Yu et al. systematically investigated the effects of treatment time, temperature, pH, plant material-to-solvent ratio, and solvent type on S. baicalensis powder. After treatment for 4 h at 50 °C, with a plant material-to-water ratio of 1:5 (w/v) and pH 6.67, substantial changes were observed in four flavonoids [1]. The data reported in the original study in μM/g are shown below.

Compound	Untreated Sample	After 4 h of Treatment
Baicalin	194.9 μM/g	3.2 μM/g
Wogonoside	43.3 μM/g	3.3 μM/g
Baicalein	80.3 μM/g	277.6 μM/g
Wogonin	17.9 μM/g	55.2 μM/g

The two glucuronides decreased substantially, while their corresponding aglycones increased markedly. Enzymological studies of endogenous GUS in S. baicalensis further support the involvement of glycoside hydrolysis in these changes [1,6].

Water thoroughly wets plant powders and alters diffusion and contact among enzymes, substrates, and the plant matrix. In materials that retain endogenous enzyme activity, aqueous treatment not only involves dissolution and release of constituents but can also provide a reaction environment that allows ongoing enzymatic transformation within the sample.

3.2 pH and Temperature Alter Net Transformation in the Intact Sample System

The purified GUS from S. baicalensis studied by Ikegami et al. exhibited an optimum pH of approximately 4.7 in a 50 mmol/L citrate buffer system [6]. In contrast, when Yu et al. investigated pretreatment of the whole S. baicalensis powder system, a relatively high degree of net conversion from glycosides to aglycones was observed around pH 6.67 [1].

These two pH values correspond to different experimental systems. Experiments with the purified enzyme reflect the catalytic properties of a single GUS under specified buffer conditions, whereas the plant-powder system simultaneously includes the tissue matrix, substrate release, mass transfer, and multiple endogenous constituents. The overall degree of transformation in a plant sample is the experimentally observed result of these factors acting together.

Temperature likewise affects multiple processes simultaneously. Yu et al. compared conditions of 5, 25, 37, 50, and 90 °C. In this S. baicalensis powder system, a relatively pronounced decrease in glycosides and increase in aglycones occurred at 50 °C [1]. Increasing temperature can alter enzymatic reaction rates and molecular diffusion while also affecting protein stability and chemical reactions involving the target compounds themselves. Different plant materials therefore have their own characteristic temperature-response ranges.

3.3 Extraction Solvents Alter the Environment for Enzymatic Transformation

Yu et al. also compared treatment with water and 75% ethanol. When samples were initially soaked in 75% ethanol at 25 °C and subsequently treated at 50 °C, transformation among baicalin, wogonoside, and their corresponding aglycones was markedly restricted [1].

The use of 75% ethanol represents the specific experimental condition employed in this study. In other plant materials, enzyme type, protein stability, initial moisture content, and sample composition may all alter the extent to which organic solvents affect enzyme activity.

Extraction solvents control, on the one hand, the partitioning and mass transfer of natural products from the plant matrix into the liquid phase and, on the other hand, the medium in which endogenous enzymes operate. Solvent composition can therefore affect both extraction yield and the chemical transformations occurring during extraction.

4 Enzymatic Transformation and Thermal Changes During Drying

4.1 Water Loss Alters the Duration of Enzymatic Reactions

Drying after plant harvest progressively reduces tissue moisture content. A higher moisture content facilitates the diffusion of enzymes and substrates; as water content decreases, many enzymatic processes that depend on an aqueous environment gradually diminish. Freshly pulverized S. baicalensis samples can undergo continued changes in glycoside composition under moisture-maintained conditions, demonstrating the close relationship between moisture status and the duration of endogenous enzyme activity [7].

Drying is also accompanied by changes in temperature and tissue structure. More rapid water loss can shorten the duration of some enzymatic transformations, whereas elevated temperatures simultaneously affect enzyme activity, mass-transfer rates, and the chemical stability of target compounds.

4.2 Responses of Scutellaria baicalensis Glycosides and Aglycones to Different Drying Methods

Zhang et al. compared sun drying, shade drying, and oven drying at 60 °C for fresh S. baicalensis roots. Baicalin, wogonoside, baicalein, and wogonin showed different changes in content under these conditions. Sun drying and shade drying were relatively favorable for retaining baicalin and wogonoside, whereas both glycosides decreased markedly during drying at 60 °C. Baicalein and wogonin showed different response patterns, with drying at 60 °C providing better relative retention of the two aglycones than sun drying or shade drying [8].

Shade drying occurs at a lower temperature but requires a longer period for water loss to be completed, whereas sun drying and oven drying involve different temperatures, rates of water loss, and treatment durations. Endogenous enzyme activity, heat-related reactions, and moisture changes therefore follow different time courses under these conditions. The net effects of the same drying method can differ between glycosides and aglycones.

4.3 Enzymatic Degradation and Thermal-Treatment Effects in Cistanche deserticola

Studies of phenylethanoid glycosides in Cistanche deserticola have shown that thermal treatment before drying can markedly alter subsequent degradation processes. Huang et al. compared untreated materials with materials subjected to steam, hot-water, and microwave pretreatments. In untreated samples, the degradation rates of echinacoside and acteoside were approximately 0.30–0.75 and 0.54–2.45 mg·mL⁻¹·h⁻¹, respectively, which were higher than those in the corresponding thermal-simulation systems and microwave-pretreated systems [10].

Another study compared compositional changes in fresh C. deserticola slices subjected to direct oven drying, treatment with hot water at 96 °C, or steaming for different durations. After steaming for 5 or 7 min, the contents of acteoside, isoacteoside, and 2′-acetylacteoside were all significantly higher than those in the direct oven-drying group (P < 0.05) [9].

Together, these two studies show that thermal treatment can reduce certain forms of enzymatic degradation while also altering tissue structure, the stability of target constituents, and their subsequent extraction and release. The measured contents after treatment are the combined result of these processes.

The principal changes involved during drying are summarized below:

Process	Effect on Sample Composition
Decrease in moisture content	Reduces molecular diffusion and the rates of some enzymatic reactions
Changes in enzyme activity	Alter the enzymatic transformation of glycosides and other constituents
Changes in temperature	Affect the rate of water loss, enzyme stability, and nonenzymatic chemical reactions
Changes in tissue structure	Alter enzyme-substrate contact and the subsequent release of constituents
Treatment duration	Determines the time span over which different types of reactions can proceed

The actual chemical composition after drying is jointly determined by the processes described above. Different target glycosides and their transformation products may respond differently to the same drying conditions.

5 Sample Pretreatment and Analytical Results

5.1 The Analytical Target Is Defined Jointly by Sampling and Processing Status

Natural-product analysis may involve samples in different states. Studies examining the composition of fresh plants at the time of sampling focus on the state before post-harvest changes have occurred, or when such changes remain limited. By contrast, studies of processing, drying, fermentation, and biotransformation use the chemical composition after treatment as the analytical target.

The same endogenous enzymatic reaction can have different significance depending on the experimental objective. Studies of glycoside content at the time of sampling focus on glycoside losses occurring during sample processing, whereas studies aimed at aglycone preparation or processing-induced transformation may treat the same reaction as part of the intended process.

Sample status is jointly defined by sampling time, tissue condition, temperature, moisture content, treatment duration, drying method, and extraction conditions. The terms “primary glycosides” and “secondary glycosides” describe transformation relationships among specific glycosides, whereas sampling and processing parameters document the actual state of the material subjected to analysis.

5.2 Experimental Characterization of Pretreatment Stability

The effects of sample pretreatment on the stability of target constituents can be characterized through parallel treatment experiments and time-course studies. For plant materials containing active endogenous enzymes, the following variables are experimentally relevant:

Pretreatment Variable	Observation
Waiting time after sampling	Time-dependent changes in glycosides and related products
Degree of cutting and pulverization	Relationship between the extent of tissue disruption and the rate of compositional change
Moisture content and amount of added water	Effect of the aqueous environment on the extent of transformation
Temperature	Combined changes in enzyme activity, mass transfer, and chemical stability
pH	Changes in net transformation within the sample system as a function of the acid-base environment
Extraction solvent and proportion	Relationship of solvent composition to enzymatic transformation and extraction yield
Drying method and duration	Concurrent changes in glycosides, transformation products, and moisture status

Studies of S. baicalensis have demonstrated the effects of pulverization, aqueous treatment, pH, temperature, solvent composition, and drying method on the contents of flavonoid glucuronides and their aglycones [1,7,8]. Studies of C. deserticola have likewise documented relationships among pretreatment before drying, changes in enzyme activity, and degradation of phenylethanoid glycosides [9,10].

When the composition at the time of sampling is the analytical target, parallel comparisons of different pretreatment methods can determine the extent to which target glycosides are lost during processing and the extent to which related transformation products are formed. The effects of freeze-drying, low-temperature storage, organic-solvent treatment, and rapid thermal treatment in different systems must be determined from stability data for the corresponding target compounds.

5.3 Changes During Pretreatment Are Directly Reflected in the Final Analytical Results

HPLC, LC-MS, and related techniques measure the chemical composition entering the analytical system after sampling, pretreatment, and extraction have been completed. Glycoside hydrolysis, oxidation, thermal transformation, and other reactions that have already occurred during pretreatment are directly reflected in chromatographic peak areas, quantitative results, and compositional ratios.

Instrumental resolution, sensitivity, and quantitative precision reflect analytical performance at the detection stage, whereas stability during sample processing determines the actual analytes entering the detection system. The substantial changes in glycoside-to-aglycone ratios caused by differences in pulverization and aqueous-treatment conditions in S. baicalensis demonstrate that sample-processing factors and instrumental detection performance affect different stages of the analytical workflow [1,7].

The appearance of new chromatographic peaks or increases in the levels of known constituents during sample processing first indicates that the chemical composition has changed between the pre- and post-treatment states. The molecular formula, sugar identity, linkage position, sugar-chain sequence, and stereochemical configuration of unknown products must then be determined using mass spectrometry, nuclear magnetic resonance spectroscopy, and other structural evidence.

6 Representative Chemical Classification Tables for Studies of Natural Glycoside Sample Processing, Endogenous Enzymatic Transformation, and Processing-Induced Compositional Changes

Table 1. Flavonoid Glucuronides and Corresponding Aglycones of Scutellaria baicalensis

Classification	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Trihydroxyflavone 7-O-glucuronide	21967-41-9	B110209	Baicalin	Analytical standard, Moligand™, ≥98% (HPLC)	Used to monitor changes in glucuronide content during tissue disruption, aqueous pretreatment, drying, and pre-extraction treatment of S. baicalensis; used in paired analysis with baicalein to investigate glycoside hydrolysis and compositional transformation.
Trihydroxyflavone	491-67-8	B107323	Baicalein	Analytical standard, Moligand™, ≥98%	Used as an aglycone reference for baicalin after deglucuronidation; used to monitor aglycone formation and changes in glycoside–aglycone ratios during tissue disruption and aqueous pretreatment.
8-Methoxyflavone 7-O-glucuronide	51059-44-0	W111385	Wogonoside	Analytical standard, ≥98%	Used to monitor changes in wogonoside content during pulverization, soaking in water, temperature treatment, and pre-extraction treatment of S. baicalensis samples; used in paired analysis with wogonin to evaluate deglucuronidation.
8-Methoxydihydroxyflavone	632-85-9	W101155	Wogonin	Analytical standard, Moligand™, ≥98%	Used as the corresponding aglycone reference for wogonoside; used to monitor aglycone formation, glycoside depletion, and changes in the flavonoid composition of S. baicalensis during sample processing.
Tetrahydroxyflavone 7-O-glucuronide	27740-01-8	S107670	Scutellarin	Analytical standard, Moligand™	Used to study the stability and compositional changes of flavonoid glucuronides during enzymatic hydrolysis, drying, and pre-extraction treatment, and for paired analysis with the corresponding aglycone.
Tetrahydroxyflavone	529-53-3	S138949	Scutellarein	Moligand™, ≥98% (HPLC)	Used as a structural reference for the aglycone corresponding to scutellarin; used for confirmation of glucuronide hydrolysis products and investigation of flavonoid aglycone formation.
6-Methoxyflavone 7-O-glucuronide	36948-76-2	O649233	Oroxylin A-7-O-glucuronide	≥99%	Used to monitor the stability of methoxyflavone glucuronides during enzymatic hydrolysis, processing, and pre-extraction treatment, and for paired analysis with oroxylin A.
6-Methoxydihydroxyflavone	480-11-5	O115707	Oroxylin A	≥98%	Used as the aglycone reference for the corresponding glucuronide; used for confirmation of enzymatic hydrolysis products and studies of glycoside–aglycone ratios and sample-processing stability.
Dihydroxyflavone 7-O-glucuronide	35775-49-6	C650716	Chrysin-7-O-glucuronide	≥99%	Used in studies of flavonoid glucuronide hydrolysis, sample pretreatment stability, and comparative evaluation of the effects of different flavonoid skeletons on deglucuronidation behavior.
Dihydroxyflavone	480-40-0	C110078	Chrysin	Analytical standard, Moligand™, ≥98%	Used as the aglycone reference for the corresponding glucuronide; used for confirmation of hydrolysis products and comparison of glycoside–aglycone composition before and after treatment.

Table 2. β-Glucuronidase, Enzymatic Substrates, and Reagents for Glucuronidation Studies

Classification	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
β-Glucuronidase	9001-45-0	G755240	β-Glucuronidase from Escherichia coli	Recombinant, ≥20,000,000 units/g protein, expressed in E. coli, aqueous glycerol solution	Used to establish in vitro glucuronide hydrolysis systems and for enzyme activity assays, substrate transformation, and stability studies of flavonoid glucuronides.
Chromogenic glucuronide substrate	10344-94-2	N159658	4-Nitrophenyl β-D-glucuronide [β-glucuronidase substrate]	≥98% (HPLC)	Used for β-glucuronidase activity assays, hydrolysis kinetics, evaluation of enzyme-inactivation conditions, and detection of residual enzyme activity during sample pretreatment.
Phenolic chromogenic product	100-02-7	P572406	p-Nitrophenol	≥99%, contains ~3% water	Used as a reference for the enzymatic hydrolysis product of nitrophenyl glucuronide; used for standard curves, product quantification, and β-glucuronidase activity analysis.
Fluorogenic glucuronide substrate	6160-80-1	M194210	4-Methylumbelliferyl β-D-glucuronide	≥98%	Used for fluorometric β-glucuronidase activity assays, detection of low levels of residual enzyme activity, and comparison of enzyme activity under different sample-processing conditions.
Coumarin fluorescent product	90-33-5	M106701	4-Methylumbelliferone (4-MU)	≥98%	Used as a reference for the hydrolysis product of fluorogenic glucuronide substrates; used for fluorescence quantification, enzyme activity standard curves, and determination of the extent of hydrolysis.
Hexuronic acid	6556-12-3	G105701	D-Glucuronic acid	Moligand™, ≥98%	Used as a reference for glucuronide composition and hydrolysis products, for sugar-acid analysis, and for studies of structural transformation of flavonoid glucuronides.
Activated glucuronic acid donor	2616-64-0	D1520605	UDP-glucuronic acid	≥98%	Used in studies of baicalein 7-O-glucuronidation, glucuronosyltransferase activity, and the formation pathway of baicalin.

Table 3. Phenylethanoid Glycosides and Related Structures Involved in Processing-Induced Transformations

Classification	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Caffeoyl phenylethanoid glycoside	61276-17-3	V101318	Acteoside	Analytical standard, Moligand™, ≥99%	Used to monitor changes in phenylethanoid glycoside content and evaluate processing quality during steaming, drying, thermal treatment, and pre-extraction treatment of Cistanche deserticola.
Trisaccharide-type caffeoyl phenylethanoid glycoside	82854-37-3	B115837	Echinacoside	Analytical standard, Moligand™, ≥98%	Used to study echinacoside content before and after processing of C. deserticola, thermal stability, extraction recovery, and changes in phenylethanoid glycoside composition.
Positional isomer of a caffeoyl phenylethanoid glycoside	61303-13-7	I115857	Isoacteoside	≥98%	Used to study changes in the isomeric composition of acteoside during processing, responses to steaming and drying, and chromatographic peak assignment.
Acetylated caffeoyl phenylethanoid glycoside	94492-24-7	A664080	2′-Acetylacteoside	≥98%	Used to analyze changes in acetylated phenylethanoid glycoside content and compositional profiles before and after thermal processing, steaming, and drying of C. deserticola.
Methoxyphenylethanoid caffeoyl glycoside	93236-42-1	C647775	Cistanoside A	≥97%	Used to study phenylethanoid glycoside composition, steaming kinetics, and multi-component quality evaluation in raw and processed C. deserticola.
Acetylated oligosaccharide-type phenylethanoid glycoside	112516-05-9	T412626	Tubuloside A	_	Used for compositional profiling of phenylethanoid glycosides in C. deserticola, as a structural reference for acetylated glycosides, and for monitoring compositional changes during processing and pre-extraction treatment.
Acetylated phenylethanoid glycoside	112516-04-8	T1287331	Tubuloside B	≥99%	Used to compare the composition of raw and steamed C. deserticola, investigate processing kinetics, and study the stability of acetylated phenylethanoid glycosides.
Decaffeoylated phenylethanoid glycoside	61548-34-3	D664285	Decaffeoylacteoside	≥98%	Used as a structural reference for the decaffeoylated form of acteoside; used to investigate caffeoyl-group changes, processing-induced transformations, and identification of degradation products.
Tyrosol glucoside	10338-51-9	S101157	Salidroside	Analytical standard, Moligand™, ≥98% (HPLC)	Used as a structural reference for monosaccharide-type phenylethanoid glycosides; used to compare the stability of simple phenylethanoid glycosides and complex phenylethanoid glycosides during enzymatic hydrolysis, drying, and extraction.
Catechol-type phenylethanol	10597-60-1	H107675	Hydroxytyrosol (DOPET)	Moligand™, ≥98%	Used as a reference for the phenylethanol structural unit and hydrolysis products of acteoside-type compounds; used in studies of processing-induced transformations, degradation products, and structural units.
p-Hydroxyphenylethanol	501-94-0	H118576	2-(4-Hydroxyphenyl)ethanol	Chromatographic standard, ≥99.5% (GC)	Used as an aglycone and structural-unit reference for tyrosol-type phenylethanoid glycosides; used for analysis of glycoside hydrolysis products, sample-processing transformations, and chromatographic analysis.
Dihydroxycinnamic acid	331-39-5	C108308	Caffeic acid	Analytical standard, Moligand™	Used as a reference for the acyl structural unit of caffeoyl phenylethanoid glycosides; used to analyze ester-bond changes, formation of free caffeic acid, and degradation products during processing.

Table 4. Cyanogenic Glycosides, Constituent Sugars, and Reagents for Enzyme-Protein Processing

Classification	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Disaccharide-type cyanogenic glycoside	29883-15-6	A107073	Amygdalin	Analytical standard, ≥98%	Used to study stepwise hydrolysis of cyanogenic glycoside sugar chains, compositional changes, and stability during tissue disruption, endogenous glycosidase activity, and sample pretreatment.
Monosaccharide-type cyanogenic glycoside	99-18-3	D139515	Prunasin	≥95%	Used for cyanogenic glycoside composition analysis, stepwise amygdalin hydrolysis systems, and studies distinguishing normal biosynthesis from post-harvest transformation processes.
Aldohexose	50-99-7	D755713	D-(+)-Glucose	Anhydrous grade, UltraBio™, ≥99.5% (HPLC), sum of enantiomers	Used as a reference for glycoside hydrolysis products, constituent sugars, and pre-extraction treatment systems, and for sugar-composition analysis of glucose-containing natural glycosides.
Inorganic salt for protein salting-out	7783-20-2	A434064	Ammonium sulfate	Anhydrous grade, reagent grade, high purity, ≥99%	Used for salting-out of glycosidase proteins, crude fractionation, enzyme-sample preparation, and studies of enzyme-activity retention and recovery under different treatment conditions.

Note: The products listed above are representative Aladdin products relevant to scientific research. Specific applications should be determined in conjunction with product specifications, batch COAs, and the target reaction or evaluation system. Additional information on product specifications, grades, and COAs can be retrieved from the Aladdin website using the “product name/CAS number/catalog number.”

References

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[4] Höglund AS, Lenman M, Falk A, Rask L. Distribution of myrosinase in rapeseed tissues. Plant Physiology, 1991, 95(1): 213–221. DOI: 10.1104/pp.95.1.213.

[5] Koroleva OA, Davies A, Deeken R, Thorpe MR, Tomos AD, Hedrich R. Identification of a new glucosinolate-rich cell type in Arabidopsis flower stalk. Plant Physiology, 2000, 124(2): 599–608. DOI: 10.1104/pp.124.2.599.

[6] Ikegami F, Matsunae K, Hisamitsu M, Kurihara T, Yamamoto T, Murakoshi I. Purification and properties of a plant β-D-glucuronidase from Scutellaria root. Biological and Pharmaceutical Bulletin, 1995, 18(11): 1531–1534. DOI: 10.1248/bpb.18.1531.

[7] Bai C, Yang J, Cao B, et al. Growth years and post-harvest processing methods have critical roles on the contents of medicinal active ingredients of Scutellaria baicalensis. Industrial Crops and Products, 2020, 158: 112985. DOI: 10.1016/j.indcrop.2020.112985.

[8] Zhang L, Zhang X, Liang Z. Post-harvest processing methods have critical roles in the contents of active ingredients of Scutellaria baicalensis Georgi. Molecules, 2022, 27(23): 8302. DOI: 10.3390/molecules27238302.

[9] Peng F, Chen J, Wang X, et al. Changes in levels of phenylethanoid glycosides, antioxidant activity, and other quality traits in Cistanche deserticola slices by steam processing. Chemical and Pharmaceutical Bulletin, 2016, 64(7): 1024–1030. DOI: 10.1248/cpb.c16-00033.

[10] Huang J, Peng Y, Ji Z, et al. Drying characteristics of Cistanche deserticola with different pretreatment and degradation mechanism of phenylethanoid glycosides during drying. Industrial Crops and Products, 2023, 204: 117339. DOI: 10.1016/j.indcrop.2023.117339.

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