Two Novel Quassinoid Glycosides with Antiviral Activity from the Samara of Ailanthus altissima

Phytochemistry investigations on Ailanthus altissima (Mill.) Swingle, a Simaroubaceae plant that is recognized as a traditional herbal medicine, have afforded various natural products, among which C₂₀ quassinoid is the most attractive for their significant and diverse pharmacological and biological activities. Our continuous study has led to the isolation of two novel quassinoid glycosides, named chuglycosides J and K, together with fourteen known lignans from the samara of A. altissima. The new structures were elucidated based on comprehensive spectra data analysis. All of the compounds were evaluated for their anti-tobacco mosaic virus activity, among which chuglycosides J and K exhibited inhibitory effects against the virus multiplication with half maximal inhibitory concentration (IC₅₀) values of 56.21 ± 1.86 and 137.74 ± 3.57 μM, respectively.     

臭椿籽挥发油的化学成分分析

采用水蒸气蒸馏法对甘肃天水产的臭椿籽挥发油进行提取，挥发油得率约为2．1％(w)；用气相色谱-质谱联用技术对挥发性成分进行了分析，鉴定了43个化合物，占挥发油相对含量的96．3％；主要成分为脂肪酸及酯、脂肪烃及甾族化合物，其中含量较高的有亚油酸、油酸、蓖麻酸和蓖麻酸甲酯。     

Heat shock,visible light or high calcium augment the cytotoxic effects of Ailanthus altissima (Swingle) leaf extracts against Saccharomyces cerevisiae cells

To gain new insight into the antimicrobial potential of Ailanthus altissima Swingle, ethanol leaf extracts were evaluated for the antifungal effects against the model yeast Saccharomyces cerevisae. The extracts inhibited the yeast growth in a dose-dependent manner, and this effect could be augmented by heat shock, exposure to visible light or exposure to high concentrations of Ca²⁺. Using transgenic yeast cells expressing the Ca²⁺-dependent photoprotein, aequorin, it was found that the leaf extracts induced cytosolic Ca²⁺ elevation. Experiments on yeast mutants with defects in Ca²⁺ transport demonstrated that the cytotoxicity of the A. altissima leaf extracts (AaLEs) was mediated by transient pulses of Ca²⁺ ions which were released into the cytosol predominantly from the vacuole. The investigation of the antifungal synergies involving AaLEs may contribute to the development of optimal and safe combination therapies for the treatment of drug-resistant fungal infections.     

A new seco-neolignan glycoside from the root bark of Ailanthus altissima

A new seco-neolignan glycoside, seco-dehydrodiconiferyl alcohol-4-O-β-D-glucopyranoside, together with eight known compounds, were obtained from the EtOH extract of the root bark of Ailanthus altissima. Their structures were elucidated based on the spectroscopic data. Three neolignan glycosides including 7,9,9'-trihydroxy-3,3',5'-trimethoxy-8-O-4'-neolignan-4-O-β-D-glucopyranoside, sonchifolignan B and citrusin B exhibited moderate in vitro inhibitory effect on tobacco mosaic virus replication with IC?? values 0.30, 0.35 and 0.26?mmol?L?1, respectively.     

Detection of TMV with ODA-H(2)O(2)-HRP voltammetric enzyme-linked immunoassay system

o-Dianisidine (ODA)-H₂O₂-horseradish peroxidase (HRP) voltammetric enzyme-linked immunoassay system has firstly been used for the detection of tobacco mosaic virus (TMV). HRP catalyzes strongly the oxidation reaction of ODA by H₂O₂, the product of which produces a sensitive second order derivative linear sweep voltammetric peak at potential of −0.56 V (versus SCE) in Britton–Robinson (BR) buffer. HRP activity has been measured with this voltammetric peak and TMV detected through immunoreaction. The detection limit for HRP is 9.25×10^-7 mU l⁻¹ and the linear range is 2.5×10⁻⁶–5.0×10⁻⁴ mU l⁻¹. The detection limit for the clarified TMV is 0.25 ng ml⁻¹ and the highest dilution ratio detected for the infected leaf sap is 1:8×10⁵. The sensitivity for TMV detection with this method is higher than that with the enzyme-linked immunosorbent spectrophotometric assay (ELISA) using ODA-H₂O₂-HRP system. The processes of the enzyme-catalyzed reaction and the electro-reduction of the product of the enzyme-catalyzed reaction have been described.     

Ailanthus altissima (Miller) Swingle fruit - new acyl β-sitosteryl glucoside and in vitro pharmacological evaluation

β-Sitosterol-3-O-(6?-O-13?-octadecenoyl)-β-D-glucoside (1), a new acyl β-sitosteryl glucoside, along with three known compounds β-sitosterol-3-O-β-D-glucoside (2), β-sitosterol (3) and methyl gallate (4) have been isolated from the ethyl acetate soluble fraction of methanolic extract of Ailanthus altissima fruits. Their structures were elucidated through spectroscopic data including 2D NMR, ESI-MS, methanolysis and oxidative cleavage of double bond. Antibacterial, antifungal, cytotoxic, phytotoxic and insecticidal activities were evaluated of compound 1, crude extract and its fractions so far for the first time. Pharmacological activities results showed that n-butanol fraction was good active against Pseudomonas aeruginosa and Salmonella typhi bacteria, and moderate active against Microsporum canis fungus. Crude extract, n-butanol and aqueous fractions showed good cytotoxicity. Moreover, compound 1, extract and all fractions showed notable phytotoxicity at higher concentrations, whereas all inactive against assayed insects.     

Two new phenolic compounds from Ardisia gigantifolia

Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as （＋）-5-（1,2-dihydroxypentyl）-benzene- 1,3-diol and （-）-5-（1,2- dihydroxypentyl）benzene- 1,3-diol.     

Two new benzolactones from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activities

Two new benzolactones, 5-methyl-6-prenyl-isobenzofuran-1(3H)-one (1), 5-hydroxymethyl-6-prenyl-isobenzofuran-1(3H)-one (2), together with four known phenolic compounds (3–6), were isolated from the leaves of Nicotiana tabacum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–6 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 1–6 exhibited high anti-TMV activities with inhibition rates in the range of 16.9–26.2%, respectively.     

Two new sesquiterpenes from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activities

Two new sesquiterpenes, nicotianasesterpenes A and B (1 and 2), together with five known sesquiterpenes (3–7) were isolated from the leaves of Nicotiana tabacum. Their structures were determined mainly by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. The anti-tobacco mosaic virus (anti-TMV) activities of compounds 1–7 were evaluated. The results revealed that compound 1 exhibited high anti-TMV activities with inhibition rates of 33.6%. This rate is high than that of positive control. The other compounds also showed potential activities with inhibition rates in the range of 18.8–28.4%, respectively.     

烟草花叶病毒在受限空间下的自组装行为

以烟草花叶病毒(TMV)为基本构建单元,研究了其在毛细管、载玻片-载玻片和柱透镜-硅片3种不同受限空间下的自组装行为。 结果表明,由于接触线有规律、重复性的粘滑运动,在3种受限体系下TMV均可组装得到高度规整的条带结构。 在毛细管内组装可得到垂直于管的长轴方向的有序条带。 随接触线深入管中心,条带跨距(l)与带宽(w)均逐渐增大。 在2个平行载玻片所构成的可控空间内所得到的条带以2条互相垂直的中心线为轴对称排列,并沿从载玻片边缘至轴向中心方向条带跨距和带宽梯度增大。 同样,利用柱透镜 硅片所组成的体系可得到类似平行线状条带,其跨距、带宽及条带高度沿从外部边缘至柱透镜/硅片接触中心方向逐渐减小。 在3种体系下,棒状TMV粒子均平行于接触线的方向取向。 TMV浓度对组装结构具有显著影响,随着浓度的增加,条带跨距和带宽均增加,直至条带结构消失形成连续膜。     

Design,Synthesis and Biological Evaluation of Novel N‐(4‐([2,2′:5′,2′′‐Terthiophen]‐5‐yl)‐2‐methylbut‐3‐yn‐2‐yl) Benzamide Derivatives

On the basis of the principle of combination of active groups, a series of novel N‐(4‐([2,2′:5′,2′′‐terthiophen]‐5‐yl)‐2‐methylbut‐3‐yn‐2‐yl) benzamide derivatives were designed, synthesized and systematically evaluated for their antiviral activity against tobacco mosaic virus (TMV). The bioassay results showed that most of these compounds displayed good anti‐TMV activity, and some of them exhibited higher antiviral activity than commercial Ningnanmycin. Especially, compound 8e with excellent anti‐TMV activity (inactivation activity, 92.3%/500 µg·mL^?1; curative activity, 85.7%/500 µg·mL^?1 and protection activity, 64.7%/500 µg·mL^?1) emerged as a potential inhibitor of plant virus TMV. Quantitative structure‐activity relationship studies proved that the van der Waals volume (V) and electronic parameter (∑(∑σ_o+σ_p) and ∑σ_m) for the substituent R¹ were very important for antiviral activities in this class of compounds.     

Bioimprinted QCM sensors for virus detection—screening of plant sap

Surface imprinting techniques on polymer-coated quartz-crystal microbalances (QCM) have been used to detect tobacco mosaic viruses (TMV) in aqueous media. Molecularly imprinted polymers (MIP), tailor-made by self organisation of monomers around a template (TMV), were generated directly on the gold electrodes. Imprinted trenches on the polymer surface mimicking the shape and surface functionality of the virus serve as recognition sites for re-adsorption after washing out of the template. The sensors are applicable to TMV detection ranging from 100 ng mL^–1 to 1 mg mL^–1 within minutes. Furthermore, direct measurements without time-consuming sample preparation are possible in complex matrices such as tobacco plant sap.Dedicated to Professor Dr. W. Fresenius on the occasion of his 90th birthday     

Two new compounds from the heartwood of Dalbergia melanoxylon

Abstract

A new neoflavonoid, named S(+)-3′-hydroxy-4′,2,4,5-tetramethoxydalbergiquinol (1), and a new benzofuran, named (2S,3S)-5-hydroxy-6-methoxy-3-methyl-2-(4′-hydroxyphenyl)-2,3dihydrobenzofuran (4), together with two known neoflavonoids, were isolated from the heartwood of Dalbergia melanoxylon. Their structures were elucidated by a combination of spectroscopic methods and comparison with the literature. Compounds 1–4 were evaluated for inhibitory activity against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 6538, Salmonella enteri CMCC 50041 and Candida albicans ATCC 289065, which all exhibited inactive or weak activity.     

Two new compounds from the roots of Myrica rubra

Two new compounds, myrubol (1) and 3-oxo-11α-hydroxyfriedelane (2), were isolated from the roots of Myrica rubra along with eight known compounds (3-10). Their structures were determined through (1)H-NMR and (13)C-NMR spectral data, including 2-D experiments (HMBC, HMQC, (1)H-(1)H COSY and NOESY) and high-resolution mass spectrometry.     

Two new compounds from the roots of Ilex pubescens

A new triterpenoid glycoside, heterobetulinic acid 3-O-β-D-glucopyranosyl(1?→?2)-β-D-xylopyranoside (1), together with a new phenylacrylic acid derivative, 3'S,4'-dihydroxyl-2'-methylene-but-1'-enyl caffeate (2), were isolated from the roots of Ilex pubescens. Their structures were elucidated by HR-ESI-MS, 1-D and 2-D NMR analyses and chemical methods. In addition, the absolute configuration of 2 was established by the application of a modified Mosher's method.     

Two new flavonoid diglycosides from Cephalotaxus sinensis

Two new acetylated flavonoid diglycosides, scutellarein-5-O-[a-L-rhamnopyranosyl-(1→ 4)-b-D-6-O-acetylglucopyranoside] (1), apigenin-5-O-[a-L-rhamnopyranosyl-(1→2)-b-D-3,6-di-O-acetylglucopyranoside] (2), were isolated from the leaves of Cephalotaxus sinensis. Their structures were determined by chemical and spectroscopic methods including HR-FAB-MS, 1H–1H COSY, HSQC and HMBC experiments.     

Neolignan and phenylpropanoid compounds from the fruits of Illicium simonsii Maxim

One new sesqui-neolignan compound, namely, sesqui-illisimonan A (1), one new neolignan, illisimonan A (2), and one new phenylpropanoid compound, illisimoid A (3) were isolated from the fruits of Illicium simonsii Maxim. The structures and absolute configurations of these compounds were determined by extensive spectroscopic, including NMR, circular dichroism and calculated electronic circular dichroism methods. The antioxidant activities of compounds 1–3 were also evaluated. Vitamin E was selected as the positive control (IC₅₀ = 49.73 ± 0.88 μM). Compounds 1 and 2 exhibited in vitro antioxidant activity with an IC₅₀ value of 55.76 ± 1.30 and 59.36 ± 0.50 μM, respectively. However, the compound 3 didn’t show obvious antioxidant activity.     

Two new steroidal derivatives from the fruit body of Chlorophyllum molybdites

Two new steroid derivatives, (22E,24R)-3alpha-ureido-ergosta-4,6,8(14),22-tetraene (1) and (22E,24R)-5alpha,8alpha-epidioxyergosta-6,9,22-triene-3beta-ol 3-O-beta-D-glucopyranoside (2) were isolated from the fruit bodies of Chlorophyllum molybdites (Agaricaceae). The structures were established by spectroscopic and chemical methods. These compounds exhibited cytotoxicity against Kato III cells.     

Two new compounds from cultures of the basidiomycete Antrodiella albocinnamomea

A new linear triterpene (1), and a new sesquiterpene (2), together with a known compound methyl indole-3-carboxylate (3) were isolated from the crude extract of Antrodiella albocinnamomea. The structures of the new compounds 1–2 were determined by comprehensive spectroscopic analysis. Compound 1 exhibited signi?cant inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) with IC₅₀ value of 1.0 μg/mL.     

Two new compounds from the stem of Vernonia cumingiana

Two new compounds vemonioside S and vemoniether S were isolated from the stem of Vernonia cumingiana, and their structures were elucidated on the basis of spectroscopic evidences.