Simultaneous Purification of Pulchinenoside B4 and B5 from Pulsatilla chinensis Using Macroporous Resin and Preparative High Performance Liquid Chromatography

Ethyl Phloretate and Ethyl p-Coumarate: Two Phytotoxins from Valsa mali and Their Pathogenic Activities

Valsa mali, the causal agent of apple Valsa canker, produces several phytotoxic metabolites to promote infection. Bioassay and ¹H nuclear magnetic resonance (NMR)-guided isolation from the culture filtrate of V. mali strain 03-8 led to the identification of seven compounds including three unreported ones, ethyl phloretate (1), ethyl p-coumarate (2), and 1-p-hydroxybenzoyl glycerol (3). Compounds 1 and 2 produced significant phytotoxicity, with average lesion areas of 6.22 and 3.74 mm², along with 2.96 and 3.47 mm² at 1 mg/ml on mature and tissue-cultured apple leaves, respectively, whereas compound 3 did not cause any symptoms on host plants. The necrotic lesion area of compounds 1 and 2 on tobacco leaves was 52.65 and 48.28 mm², respectively, compared with the negative control (0.46 mm²) at 1 mg/ml. At the same concentration, compounds 1 and 2 showed no significant influence on the germination rate of lettuce seeds while significantly decreasing the root length of lettuce seedlings to 6.74 and 4.67 mm, respectively, compared with that treated with sterile distilled water (22.01 mm). The discovery indicated that compounds 1 and 2 could be considered as non-host-specific toxins. Furthermore, compounds 1 and 2 could cause cell shrinkage, organelle damage, plasmolysis, and eventually ruptured protoplasmic membranes with cell death for their phytotoxicity in the host plants under optical microscopy and transmission electron microscopy. The results shed light on the mechanism for toxins 1 and 2 in V. mali-infected plants at the macroscopic and cellular levels.

Anemoside B4 Protects Rat Kidney from Adenine-Induced Injury by Attenuating Inflammation and Fibrosis and Enhancing Podocin and Nephrin Expression

Anemoside B4 (B4) isolated from Radix Pulsatilla has anti-inflammatory activities in the colon and antitumor effects. However, its role in the prevention and treatment of kidney injury has not been reported. Here, we reported the effects of B4 on chronic kidney injury (CKI) and studied its related mechanism based on an adenine-induced kidney injury model in rats. The results showed that serum BUN (blood urea nitrogen), Crea (creatinine), and urinary proteins increased significantly after oral administration of adenine. Meanwhile, the adenine contents in both renal tissue and urine increased markedly compared with those of normal rats. Moreover, IL-1β, IL-6, TNFα, and NFκB expression was upregulated in the kidney. Simultaneously, the expression of NLRP3 (the nucleotide-binding and oligomerization domain–like receptor, leucine-rich repeat and pyrin domain–containing 3) in the inflammasome, which consists of Caspase 1, ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain), and IL-18, was significantly upregulated. B4 could significantly decrease BUN and Crea; reduce urinary proteins in rats; suppress the expression of IL-6, IL-1β, NFκB, NLRP3, Caspase 1, ASC, and IL-18; and increase urinary adenine contents and promote its excretion. In addition, B4 also upregulated the expression of podocin and nephrin, two major podocyte proteins, and reduced the fiber collagen in the renal interstitial, suggesting that B4 could protect the glomerular matrix from adenine injury in addition to its anti-inflammatory effects. The results of this study show new perspective of B4 as a potential drug against adenine-induced renal injury.

Simultaneous purification of dihydrotanshinone, tanshinone I, cryptotanshinone, and tanshinone IIA from Salvia miltiorrhiza and their anti-inflammatory activities investigation

Dihydrotanshinone, tanshinone I, cryptotanshinone, and tanshinone IIA are major lipid-soluble constituents isolated from Salvia miltiorrhiza Bunge (Danshen). In the present study, a systematic method was developed to simultaneously isolate and purify those compounds using macroporous adsorption resins and semi-preparative HPLC with a dynamic axial compress (DAC) system. The Danshen extract (95% alcohol) was divided into three fractions using different concentrations of alcohol (0%, 45%, and 90%) on D101 column. The content of total tanshinones of 90% alcohol eluent (TTS) was over 97%. Furthermore, the anti-inflammatory effects of those samples were investigated on LPS-stimulated RAW264.7 cells and three animal models. The results showed that the anti-inflammatory effect of TTS in vitro was superior to the one of any other sample including 0% and 45% eluent, and total tanshinones capsules. In addition, TTS exhibited a stronger anti-inflammatory effect than that of dihydrotanshinone, tanshinone IIA, cryptotanshinone, and tanshinone I, respectively. For animal models, TTS could significantly suppress xylene-induced ear oedema and rescue LPS-induced septic death and acute kidney injury in mice. In summary, the separation process developed in the study was high-efficiency, economic, and low-contamination, which was fit to industrial producing. TTS is a potential agent for the treatment of inflammatory diseases.

Simultaneous purification of dihydrotanshinone, tanshinone I, cryptotanshinone, and tanshinone IIA from Salvia miltiorrhiza and their anti-inflammatory activities investigation

Dihydrotanshinone, tanshinone I, cryptotanshinone, and tanshinone IIA are major lipid-soluble constituents isolated from Salvia miltiorrhiza Bunge (Danshen). In the present study, a systematic method was developed to simultaneously isolate and purify those compounds using macroporous adsorption resins and semi-preparative HPLC with a dynamic axial compress (DAC) system. The Danshen extract (95% alcohol) was divided into three fractions using different concentrations of alcohol (0%, 45%, and 90%) on D101 column. The content of total tanshinones of 90% alcohol eluent (TTS) was over 97%. Furthermore, the anti-inflammatory effects of those samples were investigated on LPS-stimulated RAW264.7 cells and three animal models. The results showed that the anti-inflammatory effect of TTS in vitro was superior to the one of any other sample including 0% and 45% eluent, and total tanshinones capsules. In addition, TTS exhibited a stronger anti-inflammatory effect than that of dihydrotanshinone, tanshinone IIA, cryptotanshinone, and tanshinone I, respectively. For animal models, TTS could significantly suppress xylene-induced ear oedema and rescue LPS-induced septic death and acute kidney injury in mice. In summary, the separation process developed in the study was high-efficiency, economic, and low-contamination, which was fit to industrial producing. TTS is a potential agent for the treatment of inflammatory diseases.

The derivatives of Pulsatilla saponin A, a bioactive compound from Pulsatilla chinensis: Their synthesis, cytotoxicity, haemolytic toxicity and mechanism of action

The strong haemolytic toxicity of Pulsatilla saponin A (PSA) has hampered its clinical development as an injectable anticancer agent. To circumvent this challenge, twenty PSA derivatives with C ring or C-28 or C-3 modifications were synthesized and evaluated for cytotoxicity against seven selected human tumor lines, as well as for haemolytic toxicity. Structure-activity relationship (SAR) and structure-toxicity relationship (STR) correlations were also elucidated. Compared with PSA, compound 22 showed a better balance between haemolytic toxicity (HD₅₀ > 500 μM) and cytotoxicity toward lung cancer cells A549 (IC₅₀ = 4.68 μM). Molecular studies indicated that 22 was liked to lead to G1 cell cycle arrest and therefore, 22 may be a potent antitumor drug candidate.

Separation of salvianic acid A from the fermentation broth of engineered Escherichia coli using macroporous resins

Salvianic acid A (also known as danshensu) is a plant-derived polyphenolic acid, and has a variety of physiological and pharmacological activities. Our laboratory previously constructed an unprecedented artificial biosynthetic pathway in Escherichia coli and established the fermentation process to produce salvianic acid A. Here, we developed an efficient method for separating salvianic acid A from the fermentation broth of engineered Escherichia coli by macroporous resins. Among ten tested macroporous resins, the static and dynamic adsorption/desorption experiments demonstrated that X5 resin was the best to separate salvianic acid A from fermentation broth. Other parameters during static and dynamic procedures were also investigated. Under the optimum separation conditions, the average adsorption capacity of SAA were 10.66±0.54 mg/g dry resin and the desorption ratio was 85.6±4.1%. The purity and recovery yield of salvianic acid A in the final dry product were 90.2±1.5 and 81.5±2.3%, respectively. The results show that adsorption separation with macroporous resin X5 was an efficient method to prepare salvianic acid A from fermentation broth. This work will benefit the development and application of plant-derived salvianic acid A and its derivatives.

Synthesis, cytotoxicity and haemolytic activity of Pulsatilla saponin A, D derivatives

The strong haemolytic activity of Pulsatilla saponin A (PSA), D (PSD) hampered their clinical development of antitumor agents. In order to solve this problem, C-28 position modification derivatives of PSA/PSD were synthesized. The cytotoxicity and haemolytic activity of these compounds were evaluated. Structure-activity relationship and structure-toxicity relationship had been observed. The mice acute toxicity of compound 11 was reduced greatly than that of PSA. This study indicates that compound 11 may represent an interesting class of potent antitumor agents from triterpenoid saponins avoiding the haemolysis problem. The present study has important significance for the development of antitumor saponins.

Purification of ustiloxins A and B from rice false smut balls by macroporous resins

Ustiloxins are cyclopeptide mycotoxins produced by Villosiclava virens, the pathogenic fungus of rice false smut disease. Both resins SP207 and SP700 were screened to show the best adsorption and desorption properties for ustiloxins A and B among 20 commercial macroporous resins. Dynamic adsorption and desorption tests were carried out to optimize the process parameters. The optimal conditions for adsorption of resin SP207 were a processing volume as 32 bed volumes (BV), pH value of 4, and flow rate of 2 BV/h; and those for desorption of resin SP207 were a 40:60 (v/v) ratio of ethanol to water, an eluent volume of 4 BV, pH value of 4 and a flow rate of 3 BV/h. The optimal conditions for adsorption of resin SP700 were a processing volume of 26 BV, pH value as 4, flow rate of 2 BV/h; and those for desorption of resin SP700 were a 30:70 (v/v) ratio of ethanol to water solution as eluent, volume of 4 BV, pH value as 4 and flow rate of 2 BV/h. Under the optimal conditions; the purities of ustiloxins A and B obtained with resin SP207 increased 23.06-fold and 19.78-fold, respectively; and their recoveries were 96.67% and 81.25%; respectively. Similarly; the purities of ustiloxins A and B obtained with resin SP700 increased 14.75-fold and 15.33-fold and their recoveries were 93.65% and 88.64%; respectively. The results show that adsorption and desorption on SP207 and SP700 resins are effective strategies for purifying ustiloxins A and B. The developed methods are beneficial for large-scale preparation and purification of ustiloxins A and B from rice false smut balls.