Identification of antiadipogenic constituents of the rhizomes of Anemarrhena asphodeloides

Selaginellin derivatives from Selaginella tamariscina and evaluation for anti-breast cancer activity

A phytochemical investigation of Selaginella tamariscina led to the isolation of 17 selaginellin derivatives. Their inhibitory activities against breast cancer cells were screened, and preliminary structure-activity relationships were also established. Among them, dimeric selaginellin 17 showed potential activity against MDA-MB-231 cells with an IC50 value of 3.2 ± 0.1 μM, corresponding to 4-fold higher potency than the reference compound 5-FU (IC50 14.8 ± 0.2 μM). Mechanistic studies indicated that 17 could cause G2/M phase arrest in MDA-MB-231 cells and induce apoptosis accompanied by increased ROS levels.

Synthesis of difluoromethylated diarylmethanes via Fe(OTf)3-catalyzed Friedel-Crafts reaction of 2,2-difluoro-1-arylethyl phosphates

The Fe(OTf)₃-catalyzed Friedel-Crafts reaction of 2,2-difluoro-1-arylethyl phosphates with electron-rich (hetero)arenes afforded difluoromethylated diarylmethanes. Control experiments showed that Fe(OTf)₃ behaves as the Lewis acid, and that the phosphate leaving group and o- or p-alkoxy substituents on the substrates are necessary for the Fe(OTf)₃-catalyzed reaction to proceed under mild conditions.

Cytotoxic steroidal saponins from the rhizome of Anemarrhena asphodeloides

Two novel steroidal saponins, timosaponin V and W (1 and 2), together with seven known steroidal saponins (3-9), were isolated from the rhizomes of Anemarrhena asphodeloides Bunge. Their structures were elucidated by extensive 1D NMR and 2D NMR (HSQC, HMBC, ¹H-¹H COSY, and NOESY), and MS analyses. The cytotoxic activities of the isolates were evaluated. Compound 1 showed a significant cytotoxic activity against MCF-7 and HepG2 cell lines with IC₅₀ values of 2.16 ± 0.19 μM and 2.01 ± 0.19 μM, respectively.

A new monoterpene-lactone with neuroprotective activity from corn silk

A new monoterpene-lactone (1) along with five known compounds (2-6) were isolated from corn silk. The structure of the new compound was elucidated based on comprehensive spectroscopic analyses and quantum chemical calculations of electronic circular dichroism (ECD) curves. All compounds were evaluated for their neuroprotective effects against H₂O₂-induced damage in human dopaminergic neuroblastoma cells (SH-SY5Y). As a result, compound 1 exhibited weak neuroprotective activity.

Naturally Occurring Homoisoflavonoids: Phytochemistry, Biological Activities, and Synthesis (Part II)

This review documents all the new homoisoflavonoids (HIFs) that have been reported since 2007, whose total number has grown from 159 in 2007 to 295 at the present time. This review contains their structures, biological sources, plant parts they are obtained from, and, if reported, their optical rotations and melting points. The same classification is followed as an earlier review to ease reference to both reviews. This review takes note of the recent revision of plant families that were known to contain HIFs that have now been merged into one big family, Asparagaceae. Homoisoflavonoids also occur in Fabaceae and others. Two taxa, Ophiopogoan japonicus (Asparagaceae) and Caesalpinia sappan (Fabaceae), have been the source of many HIFs. These are briefly summarized. The biological properties of HIFs are also reviewed under the topics such as antioxidant, anti-inflammatory, antimicrobial, antidiabetic, and cytotoxic. The review also surveys the total synthesis of natural HIFs. All new compounds are classified and tabulated following the same style as the previous review.

Dedicated to Professor Andrew Paul Krapcho on the occasion of his 87th Birthday.

Rapid Screening of Chemical Constituents in Rhizoma Anemarrhenae by UPLC-Q-TOF/MS Combined with Data Postprocessing Techniques

Rhizoma Anemarrhenae, a famous traditional Chinese medicine (TCM), is the dried rhizome of Anemarrhena asphodeloides Bge. (Anemarrhena Bunge of Liliaceae). The medicine presents anti-inflammatory, antipyretic, sedative, and diuretic effects. The chemical constituents of Rhizoma Anemarrhenae are complex and diverse, mainly including steroidal saponins, flavonoids, phenylpropanoids, benzophenones, and alkaloids. In this study, UPLC-Q-TOF/MS was used in combination with data postprocessing techniques, including characteristic fragments filter and neutral loss filter, to rapidly classify and identify the five types of substances in Rhizoma Anemarrhenae. On the basis of numerous literature reviews and according to the corresponding characteristic fragments produced by different types of compounds in combination with neutral loss filtering, we summarized the fragmentation patterns of the main five types of compounds and successfully screened and identified 32 chemical constituents in Rhizoma Anemarrhenae. The components included 18 steroidal saponins, 6 flavonoids, 4 phenylpropanoids, 2 alkaloids, and 2 benzophenones. The method established in this study provided necessary data for the study on the pharmacological effects of Rhizoma Anemarrhenae and also provided the basis for the chemical analysis and quality control of TCMs to promote the development of a method for chemical research on TCMs.

The first total synthesis of anemarchalconyn and anemarcoumarin A

Anemarchalconyn (1) and anemarcoumarin A (2), the natural bioactive compounds isolated from the rhizomes of Anemarrhena asphodeloides Bunge (Liliaceae), were first totally synthesized using easily available materials in short, convenient routes with overall yields of 32 and 48%.

Qualitative and quantitative characterization of secondary metabolites and carbohydrates in Bai-Hu-Tang using ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and ultraperformance liquid chromatography coupled with photodiode array detector

Bai-Hu-Tang (BHT), a classic traditional Chinese medicine (TCM) formula used for clearing heat and promoting body fluid, consists of four traditional Chinese medicines, i.e., Gypsum Fibrosum (Shigao), Anemarrhenae Rhizoma (Zhimu), Glycyrrhizae Radix et Rhizoma Praeparata cum Melle (Zhigancao), and nonglutinous rice (Jingmi). The chemical composition of BHT still remains largely elusive thus far. To qualitatively and quantitatively characterize secondary metabolites and carbohydrates in BHT, here a combination of analytical approaches using ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and ultraperformance liquid chromatography coupled with photodiode array detector was developed and validated. A total of 42 secondary metabolites in BHT were tentatively or definitely identified, of which 10 major chemicals were quantified by the extracting ion mode of quadrupole time-of-flight mass spectrometry. Meanwhile, polysaccharides, oligosaccharides, and monosaccharides in BHT were also characterized via sample pretreatment followed by sugar composition analysis. The quantitative results indicated that the determined chemicals accounted for 35.76% of the total extract of BHT, which demonstrated that the study could be instrumental in chemical dissection and quality control of BHT. The research deliverables not only laid the root for further chemical and biological evaluation of BHT, but also provided a comprehensive analytical strategy for chemical characterization of secondary metabolites and carbohydrates in traditional Chinese medicine formulas.

Phosphinito palladium(ii) complexes as catalysts for the synthesis of 1,3-enynes, aromatic alkynes and ynones

An air-stable phosphinito palladium(ii) complex has been found to be an efficient catalyst in the formation of C–C bonds.

Dihydrostilbenes and diarylpropanes: Synthesis and in vitro pharmacological evaluation as potent nitric oxide production inhibition agents

An efficient synthesis of dihydrostilbenes (1-5) and diarylpropanes (6-10) is achieved from the commercially available starting materials and Wittig-Horner reaction, Claisen-Schmidt condensation and hydrogenation as key steps. Later, their nitric oxide (NO) production inhibition effects were evaluated in lipopolysaccharide (LPS)-induced RAW-264.7 macrophages as an indicator of anti-inflammatory activity. All the tested compounds significantly decreased NO production in a concentration-dependent manner except compounds 2, 6 and 8 and did not show notable cytotoxicity except compound 1. Two compounds i.e., compound 9 (hindsiipropane B) (100%; IC₅₀=1.84μM) possessed the most potent NO inhibitory activity which was even stronger than the positive control, L-NMMA (90.1%; IC₅₀=2.73μM) followed by compound 4 (75.5%; IC₅₀=2.98μM) at 10μM concentration and this finding was also further correlated by suppressed expression of LPS stimulated inducible NO synthase. Our study revealed that compound 9, a 1,3-diarylpropane scaffold with 3″,4″-dimethoxyphenyl and 3',4'-dihydroxy-2'-methoxyphenyl motifs could be considered as potential compound or lead compound for further development of NO production-targeted anti-inflammatory agents.

Phenolic compounds from the twigs and leaves of Tara (Caesalpinia spinosa)

Two new homoisoflavans, 4'-hydroxy-7-methoxy-3-benzyl-2H-chromene (1) and 3,4-cis-di-O-3-hydroxy-7-methoxy-3-(4-hydroxybenzyl)-4-ethoxychroman (2), one new coumarin, 7-methoxy-3-(4-hydroxybenzyl)coumarin (4), together with seven known phenolic compounds, bonducellin (3), anemarcoumarin A (5), (+)-syringaresinol (6), curuilignan D (7), scopoletin (8), and p-hydroxybenzaldehyde (9), were isolated from Tara (Caesalpinia spinosa Kuntze). The structures of the new compounds were characterized from their 1D and 2D NMR spectral data. All the compounds were isolated from this plant for the first time.

Concise Total Synthesis of 1,3-Diphenylpropane Derivatives Griffithanes A, B and F

Concise and efficient total syntheses of diarylpropanes griffithane A, B and F, isolated from Combretum griffithii, have been accomplished from methoxybenzaldehyde. The Claisen–Schmidt condensation between aldehyde and acetophenone was applied to form chalcone as a key step. The structures of chalcones are confirmed by crystal X-ray crystallography.

A Platform for Screening Potential Anticholinesterase Fractions and Components Obtained from Anemarrhena asphodeloides Bge for Treating Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss and cognitive impairment. Cholinesterase inhibitors are widely used for the symptomatic treatment of Alzheimer's disease to enhance central cholinergic transmission. In this study, a bioactivity-oriented screening platform based on a modified Ellman's method and HPLC-QTOF MS technique was developed to rapidly screen active agents of Anemarrhena asphodeloides Bge. The 60% ethanol fraction from an ethyl acetate extract exhibited the most potential anticholinesterase activity. Fifteen steroid saponins were identified by the mass spectrum, standards and literature reports. Twenty-five compounds were isolated from the active fraction. The results showed that compounds with the C₆–C₃–C₆ skeleton probably had both AChE and BuChE inhibitory activities. Xanthone and benzene derivatives exhibited no or little activity. Lignans showed weak BuChE inhibitory activity. The steroidal saponins demonstrated moderate or weak AChE inhibitory activity.

The genus Anemarrhena Bunge: A review on ethnopharmacology, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Anemarrhena asphodeloides Bunge. (Asparagaceae) yields Anemarrhenae Rhizoma, which has a long history to be used as a traditional medicine to treat various ailments, like cold-induced febrile disease with arthralgia, hematochezia, tidal fever and night sweats by Yin deficiency, bone-steaming, cough, and hemoptysis. It is also used as an ingredient of healthy food, wine, tea, biological toothpaste. Its importance is demonstrated by large scale to treat kinds of diseases in eastern Asian countries. The aim of this review is to provide up-to-date information about phytochemistry, pharmacology, and toxicology of Anemarrhena asphodeloides based on scientific literatures. It will build up a new foundation for further study on mechanism and development of better therapeutic agent and healthy product from Anemarrhena asphodeloides.

MATERIAL AND METHODS

All the available information on Anemarrhena asphodeloides was collected via electronic search (using PubMed, SciFinder Scholar, CNKI, TPL (www.theplantlist.org), Google Scholar, Baidu Scholar, and Web of Science).

RESULTS

Comprehensive analysis of the literatures searched through sources available above confirmed that the ethnomedical uses of Anemarrhena asphodeloides had been recorded in China, Japan, and Korea for thousands of years. The phytochemical investigation revealed the presence of steroidal saponins, flavonoids, phenylpropanoids, alkaloids, steroids, organic acids, anthraquinones, and others. Crude extracts and pure compounds from Anemarrhena asphodeloides exhibited significant pharmacological effects on the nervous system and the blood system. They also showed valuable bioactivities, such as antitumor, anti-oxidation, anti-microbial, anti-virus, anti-inflammation, anti-osteoporosis, anti-skin aging and damage as well as other activities.

CONCLUSIONS

In light of long traditional use and modern phytochemical and pharmacological studies summarized, Anemarrhena asphodeloides has demonstrated a strong potential for therapeutic and health-maintaining purposes. Both the extracts and chemical components isolated from the plant showed a wide range of biological activities. Thus more pharmacological mechanisms on main active compounds (TBII, TAIII, mangiferin and other ingredients) are necessary to be explored. In addition, as a good source of the traditional medicine, clinical studies of main therapeutic aspects (e.g. diabetes, Alzheimer׳s disease, Parkinson׳s disease, etc.), toxicity and adverse effect of Anemarrhena asphodeloides will also undoubtedly be the focus of future investigation.

Inhibitory Activity of Benzophenones from Anemarrhena asphodeloides on Pancreatic Lipase

Pancreatic lipase is a key enzyme for lipid absorption by hydrolysis of total dietary fats. Therefore, inhibition of pancreatic lipase is suggested to be an effective therapy in the regulation of obesity. The EtOAc-soluble fraction of Anemarrhena asphodeloides rhizomes significantly inhibited pancreatic lipase activity as assessed using porcine pancreatic lipase as an in vitro assay system. Further fractionation of the EtOAc-soluble fraction of A. asphodeloides led to the isolation of a new benzophenone glycoside, zimoside A (1), together with the eleven known compounds iriflophenone (2), 2,4′,6-trihydroxy-4-methoxybenzophenone (3), foliamangiferoside A (4), (2,3-dihydroxy-4-methoxyphenyl)(4-hydroxyphenyl)-methanone (5), 1,4,5,6,-tetrahydroxyxanthone (6), isosakuranetin (7), 4-hydroxybenzoic acid (8), 4-hydroxyacetophenone (9), vanillic acid (10), tyrosol (11) and 5-hydroxymethyl-2-furaldehyde (12). Among the isolated compounds, 3, 5 and 10 showed significant inhibition of pancreatic lipase activity.

Palladium-catalysed cross-coupling of vinyldisiloxanes with benzylic and allylic halides and sulfonates

The Hiyama cross-coupling reaction is a powerful method for carbon-carbon bond formation. To date, the substrate scope of this reaction has predominantly been limited to sp(2)-sp(2) coupling reactions. Herein, the palladium-catalysed Hiyama type cross-coupling of vinyldisiloxanes with benzylic and allylic bromides, chlorides, tosylates and mesylates is reported. A wide variety of functional groups were tolerated, and the synthetic utility of the methodology was exemplified through the efficient total synthesis of the cytotoxic natural product bussealin A. In addition, the antiproliferative ability of bussealin A was evaluated in two cancer-cell lines.

Four diphenylpropanes and a cycloheptadibenzofuran from Bussea sakalava from the Madagascar dry forest

Investigation of the endemic Malagasy plant Bussea sakalava for antiproliferative activity against the A2780 ovarian cancer cell line led to the isolation of the four new diphenylpropanes 1-4 and the new cycloheptadibenzofuran 5; compound 5 has a previously unreported natural product skeleton. The structure elucidation of these compounds was based on the analysis of their 1D and 2D NMR and mass spectroscopic data. Compounds 1-5 were tested for antiproliferative activity against the A2780 human ovarian cancer cell line.