Dioscorea is a genus of flowering plants, and some Dioscorea species are known and used as a source for the steroidal sapogenin diosgenin. To screen potential resource from Dioscorea species and related medicinal plants for diosgenin extraction, a rapid method to compare the contents of diosgenin in various plants is crucial. An ultra-performance liquid chromatography (UPLC) coupled with diode array detection (DAD) and electrospray ionization mass spectrometry (ESI-MS) method was developed for identification and determination of diosgenin in various plants. A comprehensive validation of the developed method was conducted. Twenty-four batches of plant samples from four Dioscorea species, one Smilax species and two Heterosmilax species were analyzed by using the developed method. The present method presented good sensitivity, precision and accuracy. Diosgenin was found in three Dioscorea species and one Heterosmilax species, namely D. zingiberensis, D. septemloba, D. collettii and H. yunnanensis. The method is suitable for the screening of diosgenin resources from plants. D. zingiberensis is an important resource for diosgenin harvesting.

Dioscorea nipponica Makino is a perennial twining herbs belonging to the family Dioscoreaceae, which is mainly distributed in the northeastern, northern, eastern and central regions of China. Traditionally, the rhizome of this herb has been commonly used by Miao and Meng ethnic groups of China to treat rheumatoid arthritis, pain in the legs and lumbar area, Kashin Beck disease, bruises, sprains, chronic bronchitis, cough and asthma. Modern pharmacological studies have discovered that this herb possesses anti-tumor, anti-inflammatory, anti-diuretic, analgesic, anti-tussive, panting-calming and phlegm-dispelling activities, along with enhancing immune function and improving cardiovascular health. In recent years, both fat-soluble and water-soluble steroidal saponins were isolated from the rhizomes of D. nipponica using silica gel column chromatography, thin layer chromatography and high performance liquid chromatography methods. Saponin and sapogenins are mainly responsible for most of the pharmacological effects of this plant. Further, the chemical components of the aboveground parts contain more than 10 kinds of phenanthrene derivatives. The present review summarizes the knowledge concerning the geographical distribution, chemical composition, pharmacological effects, toxicology studies and clinical applications of D. nipponica.

Bupleuri Radix (Chaihu) represents one of the most successful and widely used herbal medicines in Asia for the treatment of many diseases such as inflammatory disorders and infectious diseases over the past 2000 years. In the Chinese Pharmacopoeia, Chaihu is recorded as the dried roots of Bupleurum chinense DC. and B. scorzonerifolium Willd. (Umbelliferae). However, the widespread demand for the herb has tended to far outstrip the supply. Whether the aerial parts, which account for 70 ~ 85% of the dry weights of Bupleurum species, could be used as an alternative for the root has become an important scientific issue for the sustainable utilization of Bupleurum species. On the other hand, in some areas including the southeast of China as well as in Spain, the aerial parts of Bupleurum species have already been used in the folk medications. Therefore, to clarify whether the root and aerial parts of Bupleurum species are “equivalent” in the types and quantities of chemical constituents which subsequently influence their biological activities and therapeutic effects is of great importance for both the rational and sustainable use of this herb. In the present study, the chemical profiles between the root and aerial parts of Bupleurum species from different species and collected from various locations were analyzed and compared by the ultra-high performance liquid chromatography quadrupole/time of flight-mass spectrometry (UHPLC-QTOF-MS). A total of 56 peaks were identified in the root and/or aerial parts from different batches of Bupleurum species, by comparison of references standards or with those reported in the literature. Principal Component Analysis (PCA) was conducted for displaying the differentiating clustering between these two parts. The results disclosed the distinct variations between them, which indicated that the aerial parts could not be used as an alternative of root from a chemodiversity perspective. The differentiating markers resulted from the PCA analysis could also be utilized for the differentiation between them. Further validation of their biological differences is anticipated in the future study.

A high-performance liquid chromatography (HPLC) coupled with a diode array detector (DAD) and electrospray ionization mass spectrometry (ESI/MS) method was developed for the simultaneous analysis of fourteen characteristic components, including piceid, 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside, rhaponticoside, torachrysone-8-O-β-D-glucoside, emodin-1-O-β-D-glucoside, resveratrol, emodin-8-O-β-D-glucoside, chrysophanol-8-O-β-D-glucoside, physcion-8-O-β-D-glucoside, aloe-emodin, rhein, emodin, chrysophanol, and physcion, in roots of Rheum officinale Baill. (RO), Polygonum multiflorum Thunb. (PM) and Polygonum reynoutria Makino. (PR). Sample extraction was conducted on a Dionex pressurized liquid extraction (PLE) system, and the sample analysis was performed under the optimized HPLC-ESI/MS conditions. A comprehensive validation of the developed method was conducted, and the method presented a good sensitivity, repeatability and accuracy. The unique properties of the present method were validated by analyzing 15 related herb samples including 5 RO samples, 5 PM samples and 5 PR samples. Fourteen components were identified by online ESI/MS and by comparison with literature data and standard compounds, and eight of them were quantified by using a DAD simultaneously. The key characteristic components for the quality control of a single herb were found by comparing the chemical composition of these three herbs. The overall procedure is highly precise and accurate which is considered suitable for qualitative and quantitative analysis of a large number of samples.

Rhizoma Chuanxiong (RC; Chuanxiong), which is the dried rhizome of Ligusticum chuanxiong (Umbelliferae), is commonly used in Chinese medicine (CM) for improving blood circulation and dispersing blood stasis. RC is usually processed before use in clinical practice to enhance its therapeutic efficacy. This study aimed to investigate the temporal variations of the major constituents of RC by HPLC-DAD-MS during herbal processing to investigate the effects of an adjuvant (e.g., wine), steaming vs stir-frying and the optimal processing time. An HPLC-DAD-MS method was developed to determine the major constituents of the RC processed by one of the four processing methods, i.e., stir-frying, steaming, stir-frying with rice wine and steaming with rice wine. Processing was conducted over 60 min. Six major compounds, namely ferulic acid, senkyunolide I, senkyunolide H, senkyunolide A, Z-ligustilide and levistolide A, were selected as markers to analyze the effects on the markers’ levels of the different processing methods and optimize the processing time. The results indicated that (a) processing with wine had no discernible impact on the amounts of the six chemical markers in RC; (b) the amounts of the major constituents of RC subjected to steam processing were higher than those of the RC subjected to stir-fry processing. Among the four different methods evaluated for RC processing, steaming was better and the optimal time for steaming RC was 40 min.