A purge and trap technique to capture volatile compounds combined with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry to investigate the effect of sulfur-fumigation on Radix Angelicae Dahuricae

Unveiling the Chemical Composition of Sulfur-Fumigated Herbs: A Triple Synthesis Approach Using UHPLC-LTQ-Orbitrap MS-A Case Study on Steroidal Saponins in Ophiopogonis Radix

Ophiopogonis Radix (OR) is a traditional Chinese medicine. In recent years, in order to achieve the purpose of drying, bleaching, sterilizing and being antiseptic, improving appearance, and easy storage, people often use sulfur fumigation for its processing. However, changes in the chemical composition of medicinal herbs caused by sulfur fumigation can lead to the transformation and loss of potent substances. Therefore, the development of methods to rapidly reveal the chemical transformation of medicinal herbs induced by sulfur fumigation can guarantee the safe clinical use of medicines. In this study, a combined full scan-parent ions list-dynamic exclusion acquisition-diagnostic product ions analysis strategy based on UHPLC-LTQ-Orbitrap MS was proposed for the analysis of steroidal saponins and their transformed components in sulfur-fumigated Ophiopogonis Radix (SF-OR). Based on precise mass measurements, chromatographic behavior, neutral loss ions, and diagnostic product ions, 286 constituents were screened and identified from SF-OR, including 191 steroidal saponins and 95 sulfur-containing derivatives (sulfates or sulfites). The results indicated that the established strategy was a valuable and effective analytical tool for comprehensively characterizing the material basis of SF-OR, and also provided a basis for potential chemical changes in other sulfur-fumigated herbs.

The effects of sulfur fumigation processing on Panacis Quinquefolii Radix in chemical profile, immunoregulation and liver and kidney injury

ETHNOPHARMACOLOGICAL RELEVANCE

The influence of sulfur fumigation processing on chemical profile, pharmacological activity and safety of Chinese herbs has attracted great attention. Panacis Quinquefolii Radix (PQR) was more widely used as edible and medicinal than Ginseng because of its tonifying effect and characteristic of not getting inflamed. The disadvantage of sulfur fumigated (SF) Ginseng has been reported, but the systematic study of SF-PQR is deficient and urgently needed.

AIM OF THE STUDY

To systematically describe the influence of sulfur fumigation on chemical profile, characteristic products, immunoregulation and liver and kidney injury of PQR.

MATERIALS AND METHODS

ICP-MS and HPLC-DAD were used to detect 11 inorganic elements and 3 ginsenosides, respectively. Principal component analysis (PCA) was used to distinguish SF-PQR from non-sulfur fumigated (NSF)-PQR by combining the content changes of inorganic elements and ginsenosides. UPLC/Orbitrap-MS was applied to screen the characteristic products (m/z) after sulfur fumigation. For the effectiveness and safety, male KM mice were used to compare the immunomodulatory effects of NSF-PQR or SF-PQR under both healty and cyclophosphamide induced immunosuppressive conditions by net growth rate of body weight, thymus and spleen indices, serum IL-6, SOD, BUN, AST levels, and HE staining of liver and kidney.

RESULTS

Sulfur fumigation processing significantly reduced the contents of ginsenosides Rb₁, Re and Rg₁ with the elevation of inorganic elements in 20 batches PQR. Based on the scatter distribution of PCA, SF-PQR and NSF-PQR can be distinguished. According to the Rt, Precursor ion (m/z) and Product ion (m/z) produced by UPLC/Orbit trap-MS, R₁-SO₃ (m/z, 1059.53), Re-SO₃ (m/z, 1025.55), Rg₁-SO₃ (m/z, 878.47), Ro-SO₃ (m/z, 1035.32), Rb₁-SO₃ (m/z, 1179.58), and Rk₃-SO₃ (m/z, 745.40) could be confirmed as important markers for identifying SF-PQR. The effect of SF-PQR on reversing immunosuppression induced by cyclophosphamide was significantly reduced (P < 0.05) evidenced by the inhibition of net growth rate of body weight, immune organ index, IL-6 level and SOD activity. For healthy mice, SF-PQR not only failed to maintain the normal indexes, but also reduced the indexes to lower levels. After 2 weeks of continuous gastric administration, the abnormal liver and kidney functions in healthy mice were damaged and manifested by the increasing of BUN and AST levels, which was consistent with hepatic lesion area and renal tubular injury observed by HE staining.

CONCLUSION

Sulfur fumigation processing not only reduced the immunomodulatory effect of PQR, but also brought the hidden danger in liver and kidney injury. The sulfonated products provided in this paper can be applied for the identification of SF-PQR accurately.

Chemical profiles, antioxidant activity and acute toxicity of raw and sulfur-fumigated Smilacis Glabrae Rhizoma

ETHNOPHARMACOLOGICAL RELEVANCE

Smilacis Glabrae Rhizoma (SGR), known as Tu-fu-ling in the China, Japan and Korea, is an herb that has been used for clearing damp and detoxification in traditional Chinese medicine for many years. The post-harvest drying of SGR has traditionally been done by the sun, but sometimes sulfur fumigation is used instead due to its low cost and high efficiency. Recent reports show that sulfur fumigation can change the chemical constitution of herbal medicines and decrease their biology activity.

AIM OF THE STUDY

This study will investigate the changes to the chemical constitution, acute toxicity and antioxidant potential of SGR that occur after sulfur fumigation. To date, no studies have investigated these aspects simultaneously.

MATERIALS AND METHODS

An ultra-performance liquid chromatography fingerprint method was developed for analysing changes to SGR's chemical constitution caused by sulfur fumigation. The chromatography conditions were as follows: all samples were analysed on a Waters Acquity UHPLC HT3 C18 column; the linear gradient elution was conducted with a mobile phase prepared from acetonitrile and water. All calibration curves showed good linear regression (R > 0.9991) within the tested range. The method was validated for precision, accuracy, limit of detection and quantification. Total flavonoids of the raw and sulfur-fumigated samples were also determined by ultraviolet spectrophotometry. The antioxidant properties of the extracts were evaluated using both DPPH and ABTS radical scavenging assays. The acute toxicities of the raw and sulfur-fumigated samples were investigated.

RESULTS

The results demonstrate that the amounts of astilbin, neoastilbin, neoisoastilbin, isoastilbin, resveratrol and total flavonoids were lower in sulfur-fumigated samples than in raw samples. The antioxidant activity of the sulfur-fumigated samples was also significantly lower. Therefore, sulfur fumigation may cause chemical transformation, alter the chemical constitution, and decrease the bioactivity of SGR. Orally-administered doses did not cause mortality or changes in the general behaviour of tested mice. The LD50 was > 5000 mg/kg DW. However, the high-dose S-SGR mice had significant liver damage and high levels of plasma biochemical parameters (ALT, AST, DBIL, TBIL).

CONCLUSIONS

The results of the current study suggest that sulfur fumigation can decrease antioxidant activity in vitro; and that orally-administrated S-SGR is unsafe at doses > 3000 mg/kg dried materia medica. Therefore, sulfur-fumigation processing should be forbidden for SGR until its efficacy and safety has been demonstrated. An alternative method of sulfur fumigation for the post-harvest processing of SGR should also be developed.

Chemical profiling in Moutan Cortex after sulfuring and desulfuring processes reveals further insights into the quality control of TCMs by nontargeted metabolomic analysis

As a traditional processing method, sulfuring has been used in the processing of many traditional Chinese medicines (TCMs). Desulfuring, which has emerged in recent years, is a new method applied to sulfured herbs so they can comply with regulations regarding residual SO₂. Due to the chemical transformations and the residual SO₂ in the herbs, both sulfuring and desulfuring have negative effects on the safety and therapeutic effects of TCMs, and Moutan Cortex is one of the TCMs most susceptible to these effects. Here, a new strategy was developed to differentiate normal, sulfured and desulfured Moutan Cortex, and the transformations of compounds in sulfuring and desulfuring processes were analyzed using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MSE) method based on metabolomic analysis. Our findings were as follows: (1) a total of 119 compounds were identified or tentatively identified, including 9 compounds that are being reported for the first time as natural products; (2) 15 sulfocompounds were generated during the sulfuring process; (3) these sulfocompounds could not be converted back into their corresponding glycosides by the desulfuring process, and the desulfuring decreased the residual SO₂,while also removing some soluble compounds in the sulfured Moutan Cortex; and (4) 28 compounds were screened and tentatively identified as markers for distinguishing normal, sulfured and desulfured Moutan Cortex. Our findings provide a new practical strategy for evaluating how sulfuring and desulfuring affect the quality of TCMs.

Influence of sulfur fumigation on glycoside profile in Platycodonis Radix (Jiegeng)

BACKGROUND

Over recent decades, sulfur fumigation is becoming abused in processing some freshly harvested herbs used as both medicine and food, although it has been questioned whether sulfur fumigation will change the efficacy and safety of the herbs. One of the herbs commonly processed by sulfur fumigation is Platycodonis Radix (Jiegeng in Chinese). Glycosides are the main bioactive components of Jiegeng. Up to the present, no study has been carried out to evaluate the impact of sulfur fumigation on glycoside profile of Jiegeng.

METHODS

A rapid and versatile ultra-high performance liquid chromatography coupled with ultra-high resolution quadrupole time-of-flight mass spectrometry (UHPLC UHD Q-TOF MS/MS) method was developed for comprehensive analysis of the glycoside profiles of sulfur-fumigated and air-dried Jiegeng samples.

RESULTS

Twenty-three glycosides were detected in air-dried and sulfur-fumigated Jiegeng samples. After sulfur fumigation, the peak heights of eight glycosides, namely platycogenin A, platycodin D, platycodin D2, platycodin D3, polygalacin D, polygalacin D2, deapio-platycodin D and 3″-O-acetylplatycodin D2, remarkably decreased; while peak heights of five glycosides, namely syringin, lobetyolin, platycoside E, deapio-platycodin D2 and deapio-platycoside E, slightly increased; in addition, peaks of ten glycosides, platycodin A, platycodin C, platycodin V, platycoside C, 16-oxoplatycodin D, 2″-O-acetylpolygalacin D, 2″-O-acetylpolygalacin D2, 3″-O-acetylpolygalacin D, 3″-O-acetylpolygalacin D2, and platycogenic acid B, disappeared.

CONCLUSION

Sulfur fumigation caused significant changes of glycoside components of Jiegeng. Further investigations are warranted to explore how these chemical changes occurred and whether these changes would affect the efficacy and safety of Jiegeng.