Identification and ecdysteroid antagonist activity of three resveratrol trimers (suffruticosols A, B and C) from Paeonia suffruticosa

Production of Margarine Fat Containing Medium- and Long-Chain Triacylglycerols by Enzymatic Interesterification of Peony Seed Oil, Palm Stearin and Coconut Oil Blends

This paper reports the preparation of margarine fat using Lipozyme TL IM as a catalyst and peony seed oil (PSO), palm stearin (PS) and coconut oil (CO) as raw materials. The results indicate that there were no significant changes in fatty acid composition before or after interesterification of the oil samples. However, the total amount of medium- and long-chain triglycerides (MLCTs) increased from 2.92% to 11.38% in sample E1 after interesterification, mainly including LaLaO, LaMO, LaPM, LaOO, LaPO and LaPP. Moreover, the slip melting point (SMP) of sample E1 decreased from 45.9 °C (B1) to 33.5 °C. The solid fat content (SFC) of all the samples at 20 °C was greater than 10%, indicating that they could effectively prevent oil exudation. After interesterification, the samples exhibited a β' crystal form and could be used to prepare functional margarine.

Stilbenes with potent cytotoxicity from the seedcases of Paeonia suffruticosa Andrews

Stilbenes (based on the 1,2-diphenylethylene skeleton) are a class of plant polyphenols with rich structural and bioactive diversity. Twenty-six stilbenes, including five undescribed compounds (7,8-dioxy-4,3',5'-trihydroxystilbene, trans-13'-methoxygnetin H, suffruticosol E, paestibenetrimerols A and B), were isolated from the seedcases of Paeonia suffruticosa Andrews. Their structures were elucidated by spectroscopic analyses and comparison with previously reported data. The absolute configurations of trans-13'-methoxygnetin H, suffruticosol E, paestibenetrimerols A and B were assigned from their respective electronic circular dichroism (ECD) spectra. Additionally, the structures of known compounds suffruticosols A, B and rockiol B were revised and the absolute configurations of them, and along with (+)-davidiol A, were also further determined by ECD. The isolated compounds, trans-gnetin H, cis-gnetin H and suffruticosol E, were found to have potent cytotoxicity against the DU-145 and MDA-MB-231 cell lines with IC₅₀ values of 4.89-8.61 μM. The preliminary antitumor structure-activity relationship of these stilbenes is discussed as well.

Suffruticosol A elevates osteoblast differentiation targeting BMP2-Smad/1/5/8-RUNX2 in pre-osteoblasts

The Paeonia suffruticosa ANDR. (P. suffruticosa) is commonly used in traditional medicine for various purposes. Suffruticosol A (Suf-A), isolated from P. suffruticosa, is a beneficial compound with antibiofilm, antivirulence, and anti-inflammatory properties. The aim of the present study was to investigate the biological effects of Suf-A on osteogenic processes in pre-osteoblasts. It was determined here in that Suf-A (>98.02%), isolated from P. suffruticosa, showed no cytotoxicity at 0.1-30 μM; however, it induced cytotoxicity at 50-100 μM in pre-osteoblasts. Suf-A increased osteogenic alkaline phosphatase activity and expression levels of noncollagenous proteins. Adhesion and trans-migration on the extracellular matrix were potentiated by Suf-A, but not by wound-healing migration. Suf-A did not affect autophagy or necroptosis during osteoblast differentiation. We found that Suf-A increased runt-related transcription factor 2 (RUNX2) levels and mineralized matrix formation. RUNX2 expression was mediated by Suf-A-induced BMP2-Smad1/5/8 and mitogen-activated protein kinase signaling, as demonstrated by Noggin, a BMP2 inhibitor. These results suggest that Suf-A is a potential natural osteogenic compound.

Suffruticosol B Is an Osteogenic Inducer through Osteoblast Differentiation, Autophagy, Adhesion, and Migration

Suffruticosol B (Suf-B) is a stilbene found in Paeonia suffruticosa ANDR., which has been traditionally used in medicine. Stilbenes and their derivatives possess various pharmacological effects, such as anticancer, anti-inflammatory, and anti-osteoporotic activities. This study aimed to explore the bone-forming activities and mechanisms of Suf-B in pre-osteoblasts. Herein, >99.9% pure Suf-B was isolated from P. suffruticosa methanolic extracts. High concentrations of Suf-B were cytotoxic, whereas low concentrations did not affect cytotoxicity in pre-osteoblasts. Under zero levels of cytotoxicity, Suf-B exhibited bone-forming abilities by enhancing alkaline phosphatase enzyme activities, bone matrix calcification, and expression levels with non-collagenous proteins. Suf-B induces intracellular signal transduction, leading to nuclear RUNX2 expression. Suf-B-stimulated differentiation showed increases in autophagy proteins and autophagosomes, as well as enhancement of osteoblast adhesion and transmigration on the ECM. These results indicate that Suf-B has osteogenic qualities related to differentiation, autophagy, adhesion, and migration. This also suggests that Suf-B could have a therapeutic effect as a phytomedicine in skeletal disorders.

Stilbenes: Source plants, chemistry, biosynthesis, pharmacology, application and problems related to their clinical Application-A comprehensive review

Stilbenes are some of the important phenolic compounds originating from plant families like Vitaceae, Leguminaceae, Gnetaceae, and Dipterocarpaceae. Structurally, they have a C6-C2-C6 skeleton, usually with two isomeric forms. Stilbenes are biosynthesized due to biotic and abiotic stresses such as microbial infections, high temperatures, and oxidation. This review aims to provide a comprehensive overview of stilbenes' botanical sources, chemistry, biosynthetic pathways, pharmacology, and clinical applications and challenges based on up-to-date data. All included studies were collected from PubMed, ScienceDirect, Google Scholar, and CNKI, and the presented data from these indexed studies were analyzed and summarized. A total of 459 natural stilbene compounds from 45 plant families and 196 plant species were identified. Pharmacological studies also show that stilbenes have various activities such as anticancer, antimicrobial, antioxidant, anti-inflammatory, anti-degenerative diseases, anti-diabetic, neuroprotective, anti-aging, and cardioprotective effects. Stilbene synthase (STS) is the key enzyme involved in stilbene biosynthetic pathways. Studies on the therapeutic application of stilbenes pinpoint that challenges such as low bioavailability and isomerization are the major bottlenecks for their development as therapeutic drugs. Although the medicinal uses of several stilbenes have been demonstrated in vivo and in vitro, studies on the development of stilbenes deserve more attention in the future.

Investigation of developmental and reproductive effects of resveratrol in Drosophila melanogaster

Resveratrol is a chemical that attracts attention due to its antioxidative, anti-inflammatory, and estrogenic/antiestrogenic properties. In the present study, it was aimed to investigate developmental and reproductive effects (developmental periods, average numbers of offspring, sex ratios) of resveratrol in Drosophila melanogaster. Their larvae were exposed to 50, 100, and 200 μM of resveratrol. Resveratrol treatments did not affect pupation and maturation rate (P ˃ 0.05) statistically. But the pupation and maturation times were significantly extended at all doses (P ˂ 0.05). Also, 100 and 200 μM resveratrol treatments resulted in a significant decrease in the number of offspring (P ˂ 0.05). The results reveal that resveratrol, which is generally known for its positive effects, may have negative effects on the development and reproduction of invertebrates. The results of this study support the idea that resveratrol may act as an endocrine disruptor, as it is a phytoestrogen.

Phytochemical profiles and the hypoglycemic effects of tree peony seed coats

As emerging woody oil crops, the tree peony seeds recently have been attracting great attention for their metabolites and bioactivities. In this research, the phytochemical profiles of the seed coats of tree peonies from different production regions were investigated systematically. Twelve phytochemicals were separated and prepared, mainly belonging to stilbenes. A great variation in stilbene content was detected in the three Paeonia plants, and Paeonia ostii seed coats (POSC) had significantly higher contents of the stilbene compounds than other species. There were nineteen significant correlations between ecogeographical factors and the predominant compounds. A clear discrimination among the species was observed in their HPLC fingerprint and chemometric analysis. Furthermore, POSC extracts could significantly reduce the starch mediated PBG (postprandial blood glucose) levels in normal/diabetic mice. Meanwhile, in vitro enzyme tests revealed that the predominant compounds, suffruticosol B and ampelopsin D, could effectively and competitively inhibit α-glucosidase, indicating that POSC could be a natural source of hypoglycemics in the food and drug fields.

Genus Paeonia: A comprehensive review on traditional uses, phytochemistry, pharmacological activities, clinical application, and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Paeonia, which comprises approximately 52 shrubs or herbaceous perennials around the world, is the only genus of the Paeoniaceae and is pervasively distributed in Asia, southern Europe, and North America. Many species of the genus Paeonia have been used for centuries in ethnomedical medical systems.

AIM OF THE REVIEW

The present study aims to summarize the traditional uses, clinical applications, and toxicology of the genus Paeonia, to critically evaluate the state-of-the-art phytochemical and pharmacological studies of this genus published between 2011 and 2020, and to suggest directions for further in-depth research on Paeonia medicinal resources.

MATERIALS AND METHODS

Popular and widely used databases such as PubMed, Scopus, Science Direct, and Google Scholar were searched using the various search strings; from these searches, a number of citations related to the traditional uses, phytochemistry, biological activities, clinical application, and toxicology of the genus Paeonia were retrieved.

RESULTS

The use of 21 species, 2 subspecies, and 7 varieties of the genus Paeonia as traditional herbal remedies has been reported, and many ethnomedicinal uses, such as the treatment of hematemesis, blood stasis, dysmenorrhea, amenorrhea, epilepsy, spasms, and gastritis, have been recorded. The roots and root bark are the most frequently reported parts of the plants used in medicinal applications. In phytochemical investigations, 451 compounds have been isolated from Paeonia plants to date, which contains monoterpenoid glucosides, flavonoids, tannins, stilbenes, triterpenoids and steroids, and phenols. Studies of their pharmacological activities have revealed the antioxidant, anti-inflammatory, antitumour, antibacterial, antiviral, cardiovascular protective, and neuroprotective properties of the genus Paeonia. In particular, some bioactive extracts and compounds (total glucosides of peony (TGP), paeonol, and paeoniflorin) have been used as therapeutic drugs or tested in clinical trials. In addition to the "incompatibility" of the combined use of "shaoyao" and Veratrum nigrum L. roots in traditional Chinese medicine theory, Paeonia was considered to have no obvious toxicity based on the available toxicological tests.

CONCLUSION

A large number of phytochemical and pharmacological reports have indicated that Paeonia is an important medicinal herb resource, and some of its traditional uses including the treatment of inflammation and cardiovascular diseases and its use as a neuroprotective agent, have been partially confirmed through modern pharmacological studies. Monoterpenoid glucosides are the main active constituents. Although many compounds have been isolated from Paeonia plants, the biological activities of only a few of these compounds (paeoniflorin, paeonol, and TGP) have been extensively investigated. Some paeoniflorin structural analogues and resveratrol oligomers have been preliminarily studied. With the exception of several species (P. suffruticosa, P. ostii, P. lactiflora, and P. emodi) that are commonly used in folk medicine, many medicinal species within the genus do not receive adequate attention. Conducting phytochemical and pharmacological experiments on these species can provide new clues that may lead to the discovery of medicinal resources. It is necessary to identify the effective phytoconstituents of crude extracts of Paeonia that displayed pharmacological activities by bioactivity-guided isolation. In addition, comprehensive plant quality control, and toxicology and pharmacokinetic studies are needed in the future studies.

The Multifunctional Roles of Polyphenols in Plant-Herbivore Interactions

There is no argument to the fact that insect herbivores cause significant losses to plant productivity in both natural and agricultural ecosystems. To counter this continuous onslaught, plants have evolved a suite of direct and indirect, constitutive and induced, chemical and physical defenses, and secondary metabolites are a key group that facilitates these defenses. Polyphenols—widely distributed in flowering plants—are the major group of such biologically active secondary metabolites. Recent advances in analytical chemistry and metabolomics have provided an opportunity to dig deep into extraction and quantification of plant-based natural products with insecticidal/insect deterrent activity, a potential sustainable pest management strategy. However, we currently lack an updated review of their multifunctional roles in insect-plant interactions, especially focusing on their insect deterrent or antifeedant properties. This review focuses on the role of polyphenols in plant-insect interactions and plant defenses including their structure, induction, regulation, and their anti-feeding and toxicity effects. Details on mechanisms underlying these interactions and localization of these compounds are discussed in the context of insect-plant interactions, current findings, and potential avenues for future research in this area.

Fatty Acid Composition, Phytochemistry, Antioxidant Activity on Seed Coat and Kernel of Paeonia ostii from Main Geographic Production Areas

Paeonia ostii is an important woody oil plant cultivated in China on a large scale. Its seed oil is enriched with unsaturated fatty acids and a high content of alpha-linolenic acid (ALA), which are beneficial to human health. The aim of this research is to determine the qualitative traits characteristic of P. ostii seed from various production areas in China. In this study, seed quality traits were evaluated on the basis of proximate composition, content of fatty acids, tocopherol, secondary metabolites, and the antioxidant activity of seed coat (PSC) and kernel (PSK). A high content of total fatty acids (298.89–399.34 mg g⁻¹), crude protein (16.91%–22.73%), and total tocopherols (167.83–276.70 μg g⁻¹) were obtained from PSK. Significant differences were found in the content of palmitic acids (11.31–14.27 mg g⁻¹), stearic acids (2.42–4.24 mg g⁻¹), oleic acids (111.25–157.63 mg g⁻¹), linoleic acids (54.39–83.59 mg g⁻¹), and ALA (99.85–144.71 mg g⁻¹) in the 11 main production areas. Eight and seventeen compounds were detected in PSC and PSK, respectively. A significantly higher content of total phenols was observed in PSC (139.49 mg g⁻¹) compared with PSK (3.04 mg g⁻¹), which was positively related to antioxidant activity. This study indicates that seeds of P. ostii would be a good source of valuable oil and provides a basis for seed quality evaluation for the production of edible oil and potential ALA supplements from the promising woody oil plant.

Chemical characterization of main bioactive constituents in Paeonia ostii seed meal and GC-MS analysis of seed oil

The seeds of tree peony (Paeonia ostii) are promulgated as emerging edible oil crops. However, biological properties of principal constituents of peony seeds were not well studied. Fifteen main constituents including suffruticosols A and B, trans-ε-viniferin, ampelopsin E, resveratrol, trans-resveratrol-4'-O-β-d-glucopyranoside, paeoniflorin, luteolin, luteolin-4'-O-β-d-glucopyranoside, apigenin, kaempferol, oleanic acid, betulinic acid, hederagenin, and caffeic acid were isolated and identified. Their cytotoxicity against human tumor cell lines (COLO205, HT-29, HepG2, AGS, and HL-60) were evaluated. Among them, trans-ε-viniferin showed the most potent cytotoxicity against HL-60 cells (IC₅₀ 5.6 μM); ampelopsin E exhibited the most obvious antiproliferative properties on COLO205 (IC₅₀ 78.1 μM) and HT-29 (IC₅₀ 4.2 μM) cells, and betulinic acid showed the strongest growth inhibitory effects on HepG2 (IC₅₀ 6.6 μM) and AGS (IC₅₀ 5.4 μM) cells. Three enzymes (tyronsinase, α-glucosidase, and acetylcholinesterase) inhibitory activities of 12 compounds were also screened. Stilbene compounds, especially suffruticosols A and B, showed a significant inhibitory activity on all three enzymes. PRACTICAL APPLICATIONS: The cytotoxicity of 15 main constituents from peony seeds against COLO205, HT-29, HepG2, AGS, and HL-60 cells were evaluated. Among them, trans-ε-viniferin showed the most potent cytotoxicity against HL-60 cells (IC50 5.6 μM); ampelopsin E exhibited the most obvious antiproliferative properties on COLO205 (IC50 78.1 μM) and HT-29 (IC50 4.2 μM) cells, and betulinic acid showed the strongest growth inhibitory effects on HepG2 (IC50 6.6 μM) and AGS (IC50 5.4 μM) cells. Collectively, these results suggested that Paeonia ostii seed (POS) extracts are potential candidates for anticancer agents.

Profiling and simultaneous quantitative determination of oligostilbenes in Paeonia ostii seed shell from different geographical areas in China and their comparative evaluation

INTRODUCTION

The Paeonia ostii T. Hong & J. X. Zhang seed shell, characterised by a high content of oligostilbenes, is one of the two most important by-products in the preparation of seed oil. Oligostilbenes are considered characteristic constituents of the genus Paeonia, and can be used in fingerprinting to determine the geographical origin and the quality of raw materials.

OBJECTIVE

To develop and optimise a simple and reproducible high-performance liquid chromatography diode array detection (HPLC-DAD) method for the simultaneous determination of seven oligostilbenes in P. ostii seed shell from different geographical areas, and to associate the cultivation area.

METHODOLOGY

A validated HPLC method coupled with a DAD detector was performed for the detection and determination of target compounds in the samples. Optimal chromatographic conditions were achieved using an Agilent Zorbax Eclipse SB-AQ-C18 column and a gradient elution with acetonitrile and potassium dihydrogen phosphate solution.

RESULTS

The proposed quantitative method showed appropriate accuracy and precision, and was successfully applied to the routine analysis of seven oligostilbenes and the quality evaluation of 50 P. ostii seed shell samples. There were significant differences between the contents of the seven oligostilbenes in different samples (P < 0.01).

CONCLUSION

The results demonstrated that the oligostilbenes were main secondary metabolites in the P. ostii seed shells, and the content of seven components in P. ostii seed shells sourced from different cultivation areas in China was different.

Antidiabetic Stilbenes from Peony Seeds with PTP1B, α-Glucosidase, and DPPIV Inhibitory Activities

One unusual resveratrol tetramer, paeonilactiflorol (1), and 14 known compounds (2-15) were isolated from peony seeds ( Paeonia lactiflora) under the guidance of bioassay. Paeonilactiflorol (1) was determined by extensive HRESIMS, UV, IR, 1D and 2D NMR spectroscopic analyses. Most of the stilbenes showed obvious inhibition on PTP1B and α-glucosidase, superior to the monoterpene glycosides. Especially, the stilbene tetramer (1) and trimer (8) exhibited high activity inhibiting both PTP1B with IC₅₀ values of 27.23 and 27.81 μM and α-glucosidase with IC₅₀ values of 13.57 and 14.39 μM. Two trans-dimers (4 and 5) also showed dipeptidyl peptidase-4 (DPPIV) inhibitory activity (55.35% and 61.26%, 500 μM) in addition to PTP1B and α-glucosidase. Enzyme kinetic study indicated that the types of inhibition on PTP1B were noncompetitive for 3 and 5 and mixed for 8 and 10. Quantitative analysis suggested that the stilbene trimers 8 (23.17 ± 0.36 mg/g) and 10 (15.24 ± 0.25 mg/g) were the main contents in peony seeds and should be responsible for the antidiabetic effects. This investigation supports the therapeutic potential of peony seeds in the treatment of diabetes with stilbenes as the active constituents.

Anti-tumor Properties of Stilbene-based Resveratrol Analogues: Recent Results

Recent literature about stilbene-based analogues of resveratrol (1) has been reviewed, and a total of 94 compounds are reported (see structures 4 – 97), selected either for their promising anti-tumor properties or as comparative terms in SAR studies. As a general outline, these recent literature data confirm the previously reported observation that minimal modification in the nature and position of the substituents on the stilbene nucleus may cause large variations in their biological activity and, more specifically, in their anti-tumor properties. Among the polyhydroxylated stilbenes, it has been established that those with either a catechol or pyrogallol moiety are far better radical scavengers than either 1 or other analogues lacking an ortho-dihydroxy group, and this property was shown to be related to pro-apoptotic activity. In the large majority of cases where couples of E- and Z-isomers were evaluated for either cytotoxic or pro-apoptotic activity, the Z-isomers were significantly more active than their E analogues; nevertheless, a general rule stating that stilbenoids with Z configuration of the double bond display a considerably higher antiproliferative activity than their E-isomers cannot be considered as established. A variety of methoxystilbenes has been reported recently: in many cases these analogues showed either potent antiproliferative and pro-apoptotic activity or strong inhibition of TNFα-induced activation of NF- kB. Globally considered, polymethoxystilbenes are a sub-group of great interest among the resveratrol analogues: these analogues appear worthy of a deeper evaluation also in connection with their potential anti-angiogenic properties. In addition, in vivo studies indicate that methoxystilbenes undergo different metabolic conversion and have a higher bioavailability than resveratrol. The potent activity of some amino- and halogenated stilbenes is undoubtedly worthy of attention, but the toxicity of these compounds to normal cells has rarely been evaluated. In conclusion, the synthesis and evaluation of stilbene-based resveratrol analogues proved to be a highly active field of research and has recently afforded compounds with either cytotoxic or pro-apoptotic activity in the nanomolar range. Nevertheless, the exact structural determinants to optimize the anti-tumor properties of these compounds and details of their mechanism of action remain to be clarified.

Optimization of Ultrasound-Assisted Extraction of Monoterpene Glycoside from Oil Peony Seed Cake

Ultrasound-assisted extraction (UAE) of total monoterpene glycosides extract (TMGE) from oil peony seed cakes was investigated. The extraction yield was optimized using response surface methodology (RSM). The chemical constituents of the monoterpene glycosides extract were isolated by repeated column chromatography, and the contents of the main isolated monoterpene glycosides in the oil peony seed cakes were determined by HPLC. The optimum conditions were as follows: a liquid-to-solid ratio of 27 mL/g, ultrasonic extraction time of 16 min, ultrasonic extraction temperature of 26 °C, and ethanol concentration of 67%. Under these conditions, the extraction yield of TMGE was 10.24%. Twenty monoterpene glycosides were isolated from the oil peony seed cakes, and compounds 11-12, 16 and 20 showed strong inhibitory activities on NO production. TMGE from oil peony seed cakes can also to be used as promising immunosuppressive drug due to its high content of monoterpene glycosides and immune-inhibitory activity. PRACTICAL AAPPLICATION: The peony seed oil was authorized as a new food by the Ministry of Health of the People's Republic of China. Peony seed cake is one of the most important by-products in the preparation of peony seed oil, and accounts for approximately 40% of the total mass of the peony seed. Total monoterpene glycosides are the main active ingredient of oil peony seed cake. This research has optimized the extraction conditions of total monoterpene glycoside from seeds cake of Paeonia ostii, which will provide useful reference information for further studies, and offer related industries with helpful guidance in practice.

Tolerance strategies revealed in tree peony (Paeonia suffruticosa; Paeoniaceae) ecotypes differentially adapted to desiccation

PREMISE OF THE STUDY

Tree peony (Paeonia suffruticosa; Paeoniaceae) is well known for its ornamental value, edible oil, and medicinal properties. However, its growing area has been limited by drought that has been exacerbated by global climate change.

METHODS

Gene expression profiles of a drought-tolerant cultivar and a drought-sensitive cultivar during dehydration and rehydration were investigated by transcriptome analysis. Expression patterns of unigenes related to drought and recovery response and unrelated to either cultivar were classified by hierarchical clustering and real-time quantitative PCR (qPCR).

RESULTS

A total of 81,725 unigenes with a mean length of 762 nucleotides that may play roles in drought response were identified. Unigenes were characterized as being involved in lipid transport metabolism, proline metabolism, and photosynthesis. In addition, plant hormone signaling pathway genes were also characterized as potentially being involved in drought response. Expression patterns of the 20 drought-responsive unigenes verified by qPCR showed a differential expression pattern under either the drought or recovery treatment.

DISCUSSION

This is the first report to identify and verify unigenes of tree peonies with differing water sensitivity during dehydration and rehydration. This study offers a valuable resource for candidate genes involved in drought and provides insight into the breeding of drought-resistant tree peony cultivars.

Resveratrol: from diet to topical usage

The stilbene derivative resveratrol (3,5,4'-trihydroxy-stilbene; RESV) has become the subject of interest of many researchers and the pharmaceutical industries due to its well-acclaimed beneficial biological activities. Although earlier research tended to focus on the effects of RESV on cardiovascular disorders, many other studies have described the beneficial effects of RESV in the areas of cancer chemoprevention and inflammation and interest of researchers on this compound is still increasing. It is now well accepted that the effect of RESV is not just due to its so called "antioxidant" activity but mainly (if not only) because of the ability of this compound to trigger cell signaling pathways and gene expression involved in cellular defense systems. Many "in vitro" studies on RESV did not take into account that although its oral absorption is about 75% it undergoes rapid metabolism and the concentration in the blood stream is almost undetectable. For this reason interest in the topical usage of RESV by cosmeceutical skin care brands has exponentially increased in the last decade reporting in general very promising results on its beneficial effect in protecting the skin from outdoor insults, but there is still some controversy on its topical usage mainly surrounding the concentration used. Therefore, more basic research on the topical application of RESV should be performed to better understand the way it prevents cutaneous damage and whether it could be recommended as a preventive skin aging agent for all skin insults.

Resveratrol trimers from seed cake of Paeonia rockii

In the course of screening natural products for antibacterial activities, a total acetone extract of the seed cake of Paeonia rockii showed significant effects against bacterial strains. Bioactivity-guided fractionation of the EtOAc-soluble fraction of the total acetone extract resulted in the isolation and identification of five resveratrol trimers, including rockiiol C (1), gnetin H (2), suffruticosol A (3), suffruticosol B (4) and suffruticosol C (5). The relative configuration of these compounds was elucidated mainly by comprehensive 1D and 2D-NMR experiments. Compound 1 was a new compound. All isolated compounds exhibited strong antibacterial activities against Gram-positive bacteria.

Harnessing quinone methides: total synthesis of (±)-vaticanol A

Although quinone methides are often postulated as intermediates in the biosynthesis of many polyphenolic natural products, deploying their power in a laboratory setting to achieve similar bond constructions has sometimes proven challenging. Herein, a total synthesis of the resveratrol trimer vaticanol A has been achieved through three instances of quinone methide chemistry. These operations, one of which succeeded only under very specific conditions, expediently generated its [7,5]-carbocyclic core, afforded a unique sequence for dihydrobenzofuran formation, and concurrently generated, in addition to the target molecule, a series of diastereomers reflective of many other isolates.

Isolation of natural products by low-pressure column chromatography

This chapter describes the isolation of natural products using low-pressure column chromatography (LPLC) and provides a brief summary of the adsorption and size exclusion processes involved in LPLC. Different types of stationary phases used in both adsorption and size exclusion LPLC are also presented with specific examples. Various operational parameters in relation to column packing (both wet and dry), column equilibration, sample application, and column development, and a summary of generic procedures for adsorption and size exclusion LPLC are also incorporated in this chapter. Throughout the chapter, several specific examples of the application of LPLC for the isolation of various natural products including alkaloids, coumarins, flavones, and saponins from various plants are given. Many of these examples include a combination of adsorption and size exclusion chromatography to obtain specific compounds.

Natural stilbenes: an overview

Natural stilbenes have been a hot research topic due to their intricate structures and diverse biological activities. Although their molecular backbone consists only of 1,2-diphenylethylene units, stilbenes show an enormous diversity with regard to the different units present, the degree of polymerisation, and the pattern of oligomer construction. From January 1995 to the end of 2008, more than 400 new naturally occurring stilbenes were isolated and identified, and this review focuses on their structural diversity, distribution, and bioactivity.

Analysis of ‘SHUANGDAN’ granules by high-performance liquid chromatography–diode array detection–electrospray ionization tandem mass spectrometry

An HPLC-DAD-ESI-MSn method was developed for simultaneous analysis of the chemical constituents in 'SHUANGDAN' granules, a newly developed drug widely used for treating cardiovascular disease. The chromatographic separation were performed on a Zorbax Stable Bond C18 column (4.6 mmx250 mm, 5 microm) with water with 0.5% acetic acid (A) and acetonitrile (B) as mobile phase. According to the characteristic UV absorption profile, the information of molecular weight and structure provided by ESI-MSn, 29 constituents which attributed to Radix Salviae Miltiorrhizae and Cortex Moutan, respectively, were detected and 28 constituents including 14 phenolic acids, 6 diterpenoid quinones, 6 monoterpenoids and 2 other components were identified, while some isomers were distinguished based on the MSn spectra. This method was rapid and reliable for identification of constituents in complex chemical system, 'SHUANGDAN' granules, and the newly fragmentation patterns proposed could be extended to the compounds elucidation with similar framework.

Cytotoxic and antimutagenic stilbenes from seeds of Paeonia lactiflora

Cytotoxic and antimutagenic effects of a novel cis-epsilon-viniferin and five known stilbenes, transresveratrol, trans-epsilon-viniferin, gnetin H, suffruticosols A and B, isolated from the seeds of Paeonia lactiflora Pall. (Paeoniaceae) were determined against five different cancer cell lines, and mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Salmonella typhimurium TA100, respectively. Six stilbenes showed cytotoxic activity in a dose-dependent manner, and especially did potent cytotoxic activity against C6 (mouse glioma) cancer cell with IC50 values ranging from 8.2 to 20.5 microg/ml. trans-Resveratrol showed significant cytotoxic activity against HepG2 (liver hepatoma) and HT-29 (colon) human cancer cell lines with IC50 values of 11.8 and 25.2 g/ml, respectively. In contrast, trans-epsilon-viniferin and cis--viniferin, and gnetin H exhibited marked cytotoxic activity against Hela (cervicse) and MCF-7 (breast) human cancer cell lines with IC50 values of 20.4, 21.5, and 12.9 microg/ml, respectively. However, suffruticosol A and B had less cytotoxic effect against all cancer cells except C6. Meanwhile, six stilbenes exerted antimutagenic activity in a dose-dependent fashion. Of them, trans-resveratrol exhibited the strongest antimutagenic effect against MNNG with IC50 value of 27.0 microg/plate, while other five resveratrol oligomers also did moderate antimutagenic activity with IC50 values ranging from 31.7 to 35.2 microg/plate.