First total syntheses of kanjone and its natural analogues.

Kanjone (1), a bioactive furanoflavone and a potent biomolecule, was first isolated from Pongamia pinnata (L.). Herein, we have developed two approaches to synthesize kanjone as well as its natural analogues 6-methoxyisopongaglabol (2) and 6,3'-dimethoxy-[2″,3″:7,8]furanoflavone (3) starting from khellin and 3-hydroxy-4-methoxy-benzaldehyde, respectively.

Surface-Enhanced Raman Spectroscopy for Bioanalysis: Reliability and Challenges.

Surface-enhanced Raman spectroscopy (SERS) inherits the rich chemical fingerprint information on Raman spectroscopy and gains sensitivity by plasmon-enhanced excitation and scattering. In particular, most Raman peaks have a narrow width suitable for multiplex analysis, and the measurements can be conveniently made under ambient and aqueous conditions. These merits make SERS a very promising technique for studying complex biological systems, and SERS has attracted increasing interest in biorelated analysis. However, there are still great challenges that need to be addressed until it can be widely accepted by the biorelated communities, answer interesting biological questions, and solve fatal clinical problems. SERS applications in bioanalysis involve the complex interactions of plasmonic nanomaterials with biological systems and their environments. The reliability becomes the key issue of bioanalytical SERS in order to extract meaningful information from SERS data. This review provides a comprehensive overview of bioanalytical SERS with the main focus on the reliability issue. We first introduce the mechanism of SERS to guide the design of reliable SERS experiments with high detection sensitivity. We then introduce the current understanding of the interaction of nanomaterials with biological systems, mainly living cells, to guide the design of functionalized SERS nanoparticles for target detection. We further introduce the current status of label-free (direct) and labeled (indirect) SERS detections, for systems from biomolecules, to pathogens, to living cells, and we discuss the potential interferences from experimental design, measurement conditions, and data analysis. In the end, we give an outlook of the key challenges in bioanalytical SERS, including reproducibility, sensitivity, and spatial and time resolution.

Label-free surface-enhanced Raman spectroscopy detection of DNA with single-base sensitivity.

Direct, label-free detection of unmodified DNA is a great challenge for DNA analyses. Surface-enhanced Raman spectroscopy (SERS) is a promising tool for DNA analyses by providing intrinsic chemical information with a high sensitivity. To address the irreproducibility in SERS analysis that hampers reliable DNA detection, we used iodide-modified Ag nanoparticles to obtain highly reproducible SERS signals of single- and double-strand DNA in aqueous solutions close to physiological conditions. The phosphate backbone signal was used as an internal standard to calibrate the absolute signal of each base for a more reliable determination of the DNA structure, which has not been achieved before. Clear identification of DNA with single-base sensitivity and the observation of a hybridization event have been demonstrated.

Label-free detection of native proteins by surface-enhanced Raman spectroscopy using iodide-modified nanoparticles.

Proteins perform vital functional and structural duties in living systems, and the in-depth investigation of protein in its native state is one of the most important challenges in the postgenomic era. Surface-enhanced Raman spectroscopy (SERS) can provide the intrinsic fingerprint information of samples with ultrahigh sensitivity but suffers from the reproducibility and reliability issues. In this paper, we proposed an iodide-modified Ag nanoparticles method (Ag IMNPs) for label-free detection of proteins. The silver nanoparticles provide the huge enhancement to boost the Raman signal of proteins, and the coated iodide layer offers a barrier to prevent the direct interaction between the proteins and the metal surface, helping to keep the native structures of proteins. With this method, highly reproducible and high-quality SERS signals of five typical proteins (lysozyme, avidin, bovine serum albumin, cytochrome c, and hemoglobin) have been obtained, and the SERS features of the proteins without chromophore were almost identical to the respective normal Raman spectra. This unique feature allows the qualitative identification of them by simply taking the intensity ratio of the Raman peaks of tryptophan to phenylalanine residues. We further demonstrated that the method can also be used for label-free multiplex analysis of protein mixture as well as to study the dynamic process of protein damage stimulated by hydrogen peroxide. This method proves to be very promising for further applications in proteomics and biomedical research.

Two new antioxidant diarylheptanoids from the fruits of Alpinia oxyphylla.

Two new diarylheptanoids, 1-(3',5'-dihydroxy-4'-methoxyphenyl)-7-phenyl-3-heptanone (1) and 1-(2',4'-dihydroxy-3'-methoxyphenyl)-7-(4″-methoxyphenyl)-3-heptanone (2), along with known diarylheptanoid yakuchinone A (3), and five flavanoids, tectochrysin (4), chrysin (5), izalpinin (6), kaempferol 7, 4'-dimethyl ether (7), and kaempferide (8) were isolated from the fruits of Alpinia oxyphylla Miq. Their structures were determined by means of spectroscopic methods. Antioxidant activities of all the isolated compounds were evaluated using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Compounds 1-3 and 6-8 exhibited potent antioxidant activities in the DPPH assay.

[Spectrum-effect relationship between anti-HIV 1 activities and ultra-performance liquid chromatography fingerprints of Rheum species].

OBJECTIVE: To study the relationship between ultra-performance liquid chromatography (UPLC) fingerprints of Rheum species and their anti-HIV 1 activities. METHOD: Twenty two samples of 16 species belonging to genus Rheum from various sources were collected and analyzed in this study. Firstly they were assayed for the HIV-1 reverse transcriptase (RT) associated ribonuclease H (RNase H) activity. Secondly the fingerprints were established by an optimized UPLC method. Sample was analyzed by UPLC-TOF-MS/MS to identify major peaks. The possible relationship between UPLC fingerprints and anti-HIV 1 activities of Rheum species were deduced by mathematical statistics method. RESULT: Samples of R. austral, R. austral, R. hotaoense exhibited good anti-HIV 1 activities with IC50 < or = 0.2 mg x L(-1). The correlation of anti-HIV 1 activities and fingerprints showed that three compounds were the main bioactive components, and their retention times were 4.74, 7.99, 21.18 min, respectively. CONCLUSION: Compounds in Rheum species with possible anti-HIV 1 activities were deduced by spectrum-effect relationship study. This study supported for study of medicinal plants in Rheum.

Mining Therapeutic Efficacy from Treasure Chest of Biodiversity and Chemodiversity: Pharmacophylogeny of Ranunculales Medicinal Plants.

Ranunculales, comprising of 7 families that are rich in medicinal species frequently utilized by traditional medicine and ethnomedicine, represents a treasure chest of biodiversity and chemodiversity. The phylogenetically related species often have similar chemical profile, which makes them often possess similar therapeutic spectrum. This has been validated by both ethnomedicinal experiences and pharmacological investigations. This paper summarizes molecular phylogeny, chemical constituents, and therapeutic applications of Ranunculales, i.e., a pharmacophylogeny study of this representative medicinal order. The phytochemistry/metabolome, ethnomedicine and bioactivity/pharmacology data are incorporated within the phylogenetic framework of Ranunculales. The most studied compounds of this order include benzylisoquinoline alkaloid, flavonoid, terpenoid, saponin and lignan, etc. Bisbenzylisoquinoline alkaloids are especially abundant in Berberidaceae and Menispermaceae. The most frequent ethnomedicinal uses are arthritis, heat-clearing and detoxification, carbuncle-abscess and sore-toxin. The most studied bioactivities are anticancer/cytotoxic, antimicrobial, and anti-inflammatory activities, etc. The pharmacophylogeny analysis, integrated with both traditional and modern medicinal uses, agrees with the molecular phylogeny based on chloroplast and nuclear DNA sequences, in which Ranunculales is divided into Ranunculaceae, Berberidaceae, Menispermaceae, Lardizabalaceae, Circaeasteraceae, Papaveraceae, and Eupteleaceae families. Chemical constituents and therapeutic efficacy of each taxonomic group are reviewed and the underlying connection between phylogeny, chemodiversity and clinical uses is revealed, which facilitate the conservation and sustainable utilization of Ranunculales pharmaceutical resources, as well as developing novel plant-based pharmacotherapy.

Enhanced mass transfer of pulsed vacuum pressure pickling and changes in quality of sour bamboo shoots.

Sour bamboo shoot is a traditional Chinese fermented vegetable food. The traditional pickling method of sour bamboo shoots has the disadvantages of being time-consuming, inhomogeneous, and difficult to control. Pulsed vacuum pressure pickling (PVPP) technology uses pulsed vacuum pressure to enhance the pickling efficiency significantly. To demonstrate the effects of salt content and PVPP technical parameters on the fermentation of bamboo shoots, the sample salinity, pH value, color, crunchiness and chewiness, nitrite content, and lactic acid bacteria content during the pickling process were investigated. The salt content inside the bamboo shoots gradually increased to the equilibrium point during the pickling process. The pickling efficiency of bamboo shoots under PVPP technology increased by 34.1% compared to the traditional control groups. Meanwhile, the uniform salt distribution under PVPP technology also obtained better performance in comparison with the traditional groups. The pH value declined slowly from 5.96 to 3.70 with the extension of pickling time and sour flavor accumulated progressively. No significant differences were found in the color values (L *, a *, and b *) and the crunchiness of the bamboo shoot under different salt solution concentrations, vacuum pressure, and pulsation frequency ratio conditions. Colony-forming unit of lactic acid bacteria (CFU of LAB) decreased, to begin with, and then increased until the 6th day, followed by a declining trend in volatility. The nitrate content of bamboo shoots samples under PVPP treatments did not exceed the safety standard (<20 mg/kg) during the whole fermentation process, which proves the safety of PVPP technology. In conclusion, PVPP technology can safely replace the traditional method with better quality performance. The optimal PVPP processing conditions (vacuum pressure 60 kPa, 10 min vacuum pressure time vs. 4 min atmospheric pressure time, salt solution concentration 6%) have been recommended for pickling bamboo shoots with high product quality.

Two new flavan-flavanones from Sarcandra hainanensis.

Chemical study of the whole plants of Sarcandra hainanensis yielded two new biflavonoids with a flavan-flavanone skeleton, sarcandrone C (1), D (2) and 6 known compounds (3-8). Structures were elucidated on the basis of NMR spectroscopic methods.

Three new oligostilbenes from the seeds of Paeonia suffruticosa.

Three new oligostilbenes, trans-suffruticosol D (1), cis-suffruticosol D (2), and cis-gnetin H (7), were isolated along with the eight known stilbenes, trans-resveratrol (3), trans-epsilon-viniferin (4), cis-epsilon-viniferin (5), gnetin H (6), suffruticosol A (8), suffruticosol B (9), suffruticosol C (10), and cis-ampelopsin E (11) from the seeds of Paeonia suffruticosa. Compounds 3-6 were isolated for the first time from this plant species, and compound 11 was isolated for the first time from the genus Paeonia. The structures of the new compounds were elucidated based on spectral analyses, including 1D and 2D NMR experiments. The absolute configuration of compound 1 was determined by quantum chemical calculation of the electronic circular dichroism and comparison with the experimental circular dichroism spectrum.

Bioactive triterpenoids from Kadsura heteroclita.

A phytochemical study of Kadsura heteroclita led to the isolation of eight triterpenoids, including two new compounds, named kadheterilactone A (1) and kadheterilactone B (2), as well as six known compounds, longipedlactone H (3), longipedlactone A (4), longipedlactone F (5), kadsuranic acid A (6), nigranoic acid (7), and schisandronic acid (8). Their structures were elucidated on the basis of spectroscopic methods, including 2D NMR techniques. The cytotoxic activities of 1-8 were tested against several tumor cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium hydrobromide (MTT) assay in vitro. As a result, 4 and 5 turned out to be significantly cytotoxic against Hep-G2 and Bel-7402 tumor cell lines. All compounds were also tested for inhibition on HIV-1 protease (PR) and reverse transcriptase (RT). Compounds 6 and 7 showed strong inhibition on HIV-1 PR, while 8 exhibited moderate activity, others were only weakly active. No compounds were active against HIV-1 RT.

[Argument on the correct Chinese name of genus Kadsura Kaempf.ex Juss].

Family Schisandraceae is composed of two genera Schisandra and Kadsura, which are quite different in regard to the used part and medical function. Traditionally, the fruits of Schisandra plants were called 'Wuweizi' used as tonic for neurasthenia, antitussive, and sedative agents. The stems and roots of Kadsura plants, with names related to 'XueTeng', possess activating blood circulation and eliminating stasis and are used for the treatment of rheumatism, fractures and irregular menstruation. The dried fruit of Schisandra chinensis was recorded in Chinese Pharmacopoeia (2010 Edition) as 'Wuweizi', while the dried fruit of S. sphenanthera was recorded as an official origin of 'Nanwuweizi'. Historically, there was no evidence that the fruits of Kadsura plants were substituted as 'Wuweizi' either in ancient literatures or contemporary marketing. However, genus Kadsura is still popularly called 'Nanwuweizi' and plant K. longipedunculata is regarded as the origin of 'Nanwuweizi', thus this will cause confusion as well as misunderstanding of genus Kadsura. The authors recommended, therefore, the Chinese name of genus Kadsura should be 'Lengfantengshu' and K. longipedunculata with the name of 'Lengfanteng' in order to guarantee the drug authenticity.

[Effective components against HIV-1 replicative enzymes isolated from plants].

Plant active components characterized of many different structures and activities on multiple targets, have made them to be the important sources of inhibitors on HIV-1. For finding leading compounds with new structure against HIV-1, three key HIV-1 replicative enzymes (reverse transcriptase, protease and integrase) were used as screening models. The in vitro activities of 45 plant derived components isolated from Schisandraceae, Rutaceae and Ranunculaceae were reported. Within twelve triterpene components isolated, eight compounds were found to inhibit HIV-1 protease, in these eight active compounds, kadsuranic acid A (7) and nigranoic acid (8), inhibited both HIV-1 protease and integrase; Among fifteen lignans, meso-dihydroguaiaretic acid (15) and kadsurarin (16) were active on HIV-1 reverse transcriptase, and 4, 4-di(4-hydroxy-3-methoxyphenly)-2, 3-dimethylbutanol (13) active on HIV-1 integrase. All of the six alkaloids, seven flavones, and five others compounds were not active or only with low activities against HIV-1 replicative enzymes. Further studies of the triterpene components showing strong inhibitory activities on HIV-1 were warranted.

Complete assignments of 1H and 13C NMR data for new dibenzocyclooctadiene lignans from Kadsura oblongifolia.

Two new dibenzocyclooctadiene lignans, named kadoblongifolins A (1) and B (2), and one new natural product dibenzocyclooctadiene lignan, named kadoblongifolin C (3), were isolated from the stems of Kadsura oblongifolia (K. oblongifolia), together with five known ones, schizanrin F (4), propinquanin C (5), schisantherin G (6), heteroclitin Q (7), kadsurarin (8). The structures of these new lignans were elucidated by a combination of high-resolution electron ionization mass spectrometry (HR-EI-MS), (1)H NMR, (13)C NMR, HMQC, HMBC, and NOESY spectra.

Alisolide, alisols O and P from the rhizome of Alisma orientale.

A nor-protostane, alisolide (1), a rearranged protostane, alisol O (2), and a 2,3-seco-protostane triterpene, alisol P (3), were isolated from the rhizomes of Alisma orientale, along with eight known protostane triterpenes. The structures were elucidated to be (17S)-3,11-dioxo-23-nor-protost-12-en-23(17)-olide, 3-oxo-11beta,23-dihydroxy-24,24-dimethyl-26,27-dinorprotost-13(17)-en-25-oic acid, and (20R,23S,24R)-23,24,25-trihydroxy-2,3-seco-protost-13(17)-en-3-oic acid 2,11beta-lactone, respectively, by interpretation of spectroscopic data.

[Chemical study on ethyl acetate portion of Ehretia thyrsiflora, boraginaceae species of Kudingcha].

OBJECTIVE: To investigate the chemical constituents of Ehretia thyrsiflora. METHOD: Compounds were isolated by using silica gel, Sephadex LH-20 and RP-C18 chromatography; their structures were elucidated by means of spectral data analysis. RESULT: Seven compounds were isolated and identified as methyl rosmarinate (1), caffeic acid (2), quercetin (3), kampferol (4), kaempferol 3-O-alpha-D-arabinoside (5), quercetin 3-O-alpha-D-arabinoside (6), and p-hydroxy benzoic acid (7). CONCLUSION: All these compounds were isolated from E. thyrsiflora for the first time. Compounds 2-7 were isolated from genus Ehretia for the first time.

[Chemical constituents from stems of Schisandra propinqua].

OBJECTIVE: To study the chemical constituents in the stems of Schisandra propinqua and evaluate their effects on proliferation of vascular smooth muscle cells (VSMCs) in vitro by MTT assay. METHOD: The compounds were isolated and purified by various column chromatographic techniques and their structures were elucidated on the basis of spectral analysis (ESI-MS, 1H-NMR, 13C-NMR). RESULT: Five compounds were isolated and identified as galgravin (1), veraguensin (2), octadecanoic acid 2, 3-dihydroxypropyl ester (3), hexadecanoic acid 2, 3-dihydroxypropy ester (4), tetracosanoic acid 2, 3-dihydroxypropyl ester (5). CONCLUSION: All the compounds were isolated for the first time from the plant. 1, 2, 5 showed inhibiting effects on vascular smooth muscle cell (VSMCs) proliferation in vitro.

In silico approach in reveal traditional medicine plants pharmacological material basis.

In recent years, studies of traditional medicinal plants have gradually increased worldwide because the natural sources and variety of such plants allow them to complement modern pharmacological approaches. As computer technology has developed, in silico approaches such as virtual screening and network analysis have been widely utilized in efforts to elucidate the pharmacological basis of the functions of traditional medicinal plants. In the process of new drug discovery, the application of virtual screening and network pharmacology can enrich active compounds among the candidates and adequately indicate the mechanism of action of medicinal plants, reducing the cost and increasing the efficiency of the whole procedure. In this review, we first provide a detailed research routine for examining traditional medicinal plants by in silico techniques and elaborate on their theoretical principles. We also survey common databases, software programs and website tools that can be used for virtual screening and pharmacological network construction. Furthermore, we conclude with a simple example that illustrates the whole methodology, and we present perspectives on the development and application of this in silico methodology to reveal the pharmacological basis of the effects of traditional medicinal plants.