LC Analysis of Lignans from Schisandra sphenanthera Rehd. et Wils

Optimization of the Extraction Process and Biological Activities of Triterpenoids of Schisandra sphenanthera from Different Medicinal Parts and Growth Stages

Schisandra sphenanthera Rehd. et Wils., as a traditional Chinese medicine, has important medicinal value. In the market, the availability of the fruit of S. sphenanthera mainly relies on wild picking, but many canes and leaves are discarded during wild collection, resulting in a waste of resources. The canes and leaves of S. sphenanthera contain various bioactive ingredients and can be used as spice, tea, and medicine and so present great utilization opportunities. Therefore, it is helpful to explore the effective components and biological activities of the canes and leaves to utilize S. sphenanthera fully. In this study, the response surface method with ultrasound was used to extract the total triterpenoids from the canes and leaves of S. sphenanthera at different stages. The content of total triterpenoids in the leaves at different stages was higher than that in the canes. The total triterpenoids in the canes and leaves had strong antioxidant and antibacterial abilities. At the same time, the antibacterial activity of the total triterpenoids against Bacillus subtilis and Pseudomonas aeruginosa was stronger than that against Staphylococcus aureus and Escherichia coli. This study provides the foundation for the development and utilization of the canes and leaves that would relieve the shortage of fruit resources of S. sphenanthera.

Microbial communities of Schisandra sphenanthera Rehd. et Wils. and the correlations between microbial community and the active secondary metabolites

Background

Schisandra sphenanthera Rehd. et Wils. is a plant used in traditional Chinese medicine (TCM). However, great differences exist in the content of active secondary metabolites in various parts of S. sphenanthera. Do microorganisms critically influence the accumulation of active components in different parts of S. sphenanthera?

Methods

In this study, 16S/ITS amplicon sequencing analysis was applied to unravel microbial communities in rhizospheric soil and different parts of wild S. sphenanthera. At the same time, the active secondary metabolites in different parts were detected, and the correlation between the secondary metabolites and microorganisms was analyzed.

Results

The major components identified in the essential oils were sesquiterpene and oxygenated sesquiterpenes. The contents of essential oil components in fruit were much higher than that in stem and leaf, and the dominant essential oil components were different in these parts. The dominant components of the three parts were γ-muurolene, δ-cadinol, and trans farnesol (stem); α-cadinol and neoisolongifolene-8-ol (leaf); isosapathulenol, α-santalol, cedrenol, and longiverbenone (fruit). The microbial amplicon sequences were taxonomically grouped into eight (bacteria) and seven (fungi) different phyla. Community diversity and composition analyses showed that different parts of S. sphenanthera had similar and unique microbial communities, and functional prediction analysis showed that the main functions of microorganisms were related to metabolism. Moreover, the accumulation of secondary metabolites in S. sphenanthera was closely related to the microbial community composition, especially bacteria. In endophytic bacteria, Staphylococcus and Hypomicrobium had negative effects on five secondary metabolites, among which γ-muurolene and trans farnesol were the dominant components in the stem. That is, the dominant components in stems were greatly affected by microorganisms. Our results provided a new opportunity to further understand the effects of microorganisms on the active secondary metabolites and provided a basis for further research on the sustainable utilization of S. sphenanthera.

Analysis of Softwood Lignans by Comprehensive Two-Dimensional Liquid Chromatography

Lignans constitute a large group of phenolic plant secondary metabolites possessing high bioactivity. Their accurate determination in plant extracts with a complex chemical composition is challenging and requires advanced separation techniques. In the present study, a new approach to the determination of lignans in coniferous knotwood extracts as the promising industrial-scale source of such compounds based on comprehensive two-dimensional liquid chromatography separation and UV spectrophotometric detection is proposed. First and second-dimension column screening showed that the best results can be obtained using a combination of non-polar and polar hydroxy group embedded octadecyl stationary phases with moderate (~40%) "orthogonality". The optimization of LC × LC separation conditions allowed for the development of a new method for the quantification of the five lignans (secoisolariciresinol, matairesinol, pinoresinol, 7-hydroxymatairesinol, and nortrachelogenin) in knotwood extracts with limits of quantification in the range of 0.27-0.95 mg L-1 and a linear concentration range covering at least two orders of magnitude. Testing the developed method on coniferous (larch, fir, spruce, and pine) knotwood extracts demonstrated the high selectivity of the analysis and the advantages of LC × LC in the separation and accurate quantification of the compounds co-eluting in one-dimensional HPLC.

A Comprehensive Review of the Main Lignan Components of Schisandra chinensis (North Wu Wei Zi) and Schisandra sphenanthera (South Wu Wei Zi) and the Lignan-Induced Drug-Drug Interactions Based on the Inhibition of Cytochrome P450 and P-Glycoprotein Activities

Wu Wei Zi is the dried fruit of Schisandra chinensis (Turcz.) Baill. or Schisandra sphenanthera Rehd. et Wils. (family Magnoliaceae). As a homology of medicine and food, it has been widely used in China for thousands of years, to tonify the kidney, and ameliorate neurological, cardiovascular, liver, and gastrointestinal disorders. As its increasing health benefits and pharmacological value, many literatures have reported that the combination of Wu Wei Zi in patients has led to fluctuations in the blood level of the combined drug. Therefore, it is extremely important to evaluate its safety concern such as drug-drug interactions (DDIs) when patients are under the poly-therapeutic conditions. This review summarized the effects of Wu Wei Zi extract and its major lignan components on cytochrome P450 and P-glycoprotein activities, the change of which could induce metabolic DDIs. Our review also elaborated on the differences of the major lignan components of the two Schisandra species, as well as the absorption, distribution, metabolism, and elimination of the major lignans. In conclusion, these results would enhance our understanding of the DDI mechanisms involving Wu Wei Zi, and may potentially untangle some differing and conflicting results in the future.

The Chemical Composition and Functional Properties of Essential Oils from Four Species of Schisandra Growing Wild in the Qinling Mountains, China

The aim of this study was to investigate the chemical composition and functional properties of the essential oils from the plants Schisandra grandiflora (Wall.) Hook. f. et Thoms, Schisandra rubriflora (Franch). Rehd. et Wils., Schisandra sphenanthera Rehd. et Wils., and Schisandra propinqua (Wall.) Baill var. sinensis Oliv. collected in the Qinling Mountains. Under the optimum conditions of the ultrasonic-assisted extraction method, the extraction yields were 7.51% (S. grandiflora), 6.91% (S. rubriflora), 6.11% (S. sphenanthera), and 5.88% (S. propinqua). A total of 86 components were identified from four species of Schisandra and 16 components were shared among the essential oils of all samples with different contents. However, some components were identified only in a certain plant, for example, β-caryophyllen (S. grandiflora), α-bulnesene (S. rubriflora), and α-Chamigrene (S. propinqua). Terpenoids (sesquiterpenes and oxygenated sesquiterpenes), accounting for 73.87–82.08% of the total compounds, were the main components. Meanwhile, the antioxidant activities of the essential oils were evaluated through three free radical scavenging assays and a reducing power assay, which were related to the contents of the individual bioactive composition. These results provide a phytochemical foundation for the use of four species, and for the further study of the identification of Schisandra species.

Predictions of potential geographical distribution and quality of Schisandra sphenanthera under climate change

Climate change will significantly affect plant distribution as well as the quality of medicinal plants. Although numerous studies have analyzed the effect of climate change on future habitats of plants through species distribution models (SDMs), few of them have incorporated the change of effective content of medicinal plants. Schisandra sphenanthera Rehd. et Wils. is an endangered traditional Chinese medical plant which is mainly located in the Qinling Mountains. Combining fuzzy theory and a maximum entropy model, we obtained current spatial distribution of quality assessment for S. spenanthera. Moreover, the future quality and distribution of S. spenanthera were also projected for the periods 2020s, 2050s and 2080s under three different climate change scenarios (SRES-A1B, SRES-A2 and SRES-B1 emission scenarios) described in the Special Report on Emissions Scenarios (SRES) of IPCC (Intergovernmental Panel on Climate Change). The results showed that the moderately suitable habitat of S. sphenanthera under all climate change scenarios remained relatively stable in the study area. The highly suitable habitat of S. sphenanthera would gradually decrease in the future and a higher decline rate of the highly suitable habitat area would occur under climate change scenarios SRES-A1B and SRES-A2. The result suggested that in the study area, there would be no more highly suitable habitat areas for S. sphenanthera when the annual mean temperature exceeds 20 °C or its annual precipitation exceeds 1,200 mm. Our results will be influential in the future ecological conservation and management of S. sphenanthera and can be taken as a reference for habitat suitability assessment research for other medicinal plants.

Schisphenlignans A-E: five new dibenzocyclooctadiene lignans from Schisandra sphenanthera

Five new dibenzocyclooctadiene lignans, schisphenlignans A-E (1-5), together with eight known ones, were isolated from the stems of Schisandra sphenanthera. The structures of 1-5 were elucidated based on the analysis of their NMR, MS and circular dichroism (CD) spectra. Some isolates were tested for their acute activities on insulin sensitivity in 3T3-L1 differentiated adipocytes, but none of them showed significant bioactivity with 10 µM administration of the tested compounds.

Six new lignans from the leaves and stems of Schisandra sphenanthera

Six new lignans, schisphenlignans F-K (1-6), together with ten known ones, were isolated from the leaves and stems of Schisandra sphenanthera. Their structures were elucidated on the basis of spectroscopic methods, including extensive NMR, MS and CD spectra. In addition, some compounds were tested for their acute activity on insulin sensitivity in 3T3-L1 differentiated adipocytes and anti-HIV-1 activity.

Chemical analysis of twelve lignans in the fruit of Schisandra sphenanthera by HPLC-PAD-MS

The fruit of S. sphenanthera, known as "Nanwuweizi", has been widely used as traditional Chinese medicine for several thousand years. However, the current determination methods are not sufficient to evaluate its quality. An accurate, sensitive and reliable high performance liquid chromatography coupled with photodiode array detection and mass spectrum (HPLC-PAD-MS) was developed for quantitative analysis of twelve lignans (schisandrol A, schisandrol B, gomisin G, schisantherin A, schisantherin D, schisanhenol, (+)-anwulignan, deoxyschisandrin, schisandrin B, schisandrin C, 6-O-benzoylgomisin O, and interiotherin A) in the fruit of S. sphenanthera. The chromatographic conditions and extraction procedures were optimized during the study. The identity of chromatographic peaks in the sample HPLC profiles was confirmed by comparing the retention time, ultraviolet (UV) spectra and MS data with reference compounds. The validated method was successfully used to determine the twelve lignans in the samples collected from different localities in China. The hierarchical clustering analysis (HCA) and principal components analysis (PCA) were successfully applied to the data of twelve lignans from the HPLC profiles in sixteen batches of the fruit of S. sphenanthera to discriminate the samples with different sources. Moreover, the results of the loading plot of the PCA indicated that schisantherin A, (+)-anwulignan, and deoxyshisandrin were found to be the main constituents in the fruit of S. sphenanthera, and which could be chosen as the chemical markers for evaluate the quality of the fruit of S. sphenanthera. The results indicated that the developed method was readily utilized as a quality evaluation method for the fruit of S. sphenanthera.