Stereoselective reduction of arteannuin B and its chemical transformations

Absolute stereochemistry of dihydroarteannuin B 5 obtained by the reduction of arteannuin B 3 with Ni₂B, NaBH₄ or CdCl₂-Mg-MeOH-H₂O has been established by 2D NMR and single crystal X-ray diffraction studies. Some experiments aimed at the synthesis of dihydrodeoxyarteannuin B [C-4, 5 double bond isomer of 11] are also discussed.     

Anti-Helicobacter pylori Activity of Artemisia ludoviciana subsp. mexicana and Two of Its Bioactive Components,Estafiatin and Eupatilin

Artemisia ludoviciana subsp. mexicana has been traditionally used for the treatment of digestive ailments such as gastritis, whose main etiological agent is Helicobacter pylori. In a previous screening study, the aqueous extract exhibited a good in vitro anti-H. pylori activity. With the aim of determining the efficacy of this species as a treatment for H. pylori related diseases and finding bioactive compounds, its aqueous extract was subjected to solvent partitioning and the fractions obtained were tested for their in vitro anti-H. pylori effect, as well as for their in vivo gastroprotective and anti-inflammatory activities. The aqueous extract showed a MIC = 250 µg/mL. No acute toxicity was induced in mice. A gastroprotection of 69.8 ± 3.8%, as well as anti-inflammatory effects of 47.6 ± 12.4% and 38.8 ± 10.2% (by oral and topical administration, respectively), were attained. Estafiatin and eupatilin were isolated and exhibited anti-H. pylori activity with MBCs of 15.6 and 31.2 µg/mL, respectively. The finding that A. ludoviciana aqueous extract has significant anti-H. pylori, gastroprotective and anti-inflammatory activities is a relevant contribution to the ethnopharmacological knowledge of this species. This work is the first report about the in vivo gastroprotective activity of A. ludoviciana and the anti-H. pylori activity of eupatilin and estafiatin.     

Biosynthesis of silver nanoparticles using Onosma sericeum Willd. and evaluation of their catalytic properties and antibacterial and cytotoxic activity

In this study, silver nanoparticle (AgNP) synthesis was carried out using Onosma sericeum Willd. aqueous extract for the first time, with a simple, economical, and green method without the need for any other organic solvent or external reducing or stabilizing agent. A variety of AgNPs, all of different particle sizes, were synthesized by controlling the silver ion concentration, extract volume, temperature, and pH. It was determined that the optimum conditions for AgNP synthesis were 1 mM AgNO3, pH 8, 25 °C, 20 g/200 mL extract, silver nitrate, and extract ratio 5:1 (v/v). The AgNPs were defined using UV-Vis spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The particle size distribution and zeta potential measurements of the AgNPs were measured using the dynamic light scattering (DLS) technique. It was determined that the AgNPs with a particle size of less than 10 nm showed a higher catalytic effect in the reduction of 2-nitrobenzenamine. It was also found that these nanoparticles had a cytotoxic effect on the MCF-7 breast cancer cell line depending on dosage and time. The resulting IC50 values were between 76.63 µg/mL and 169.77 µg/mL. Furthermore, the biosynthesized AgNPs showed effective antibacterial activity against the Acinetobacter baumannii bacteria. The results of the study showed that synthesized AgNPs can have a promising role in biomedical and nanobiotechnology applications.     

Artselenoide, a New Dimeric Guaianolide from Artemisia selengensis

Inaprelindnary.ommunication',wehavereportedonanewguaianolideartseleninisolatedfromArtemisiaselengensisTurcz(Compositae).Inthepresentpaperwedescribethestructureelucidationofartselenoide1obtainedasanewdimericguaianolidefromthesamepart.1wasobtainedascolorlesspowders,mpl85-l86D,[a]." l25(cO.l,MeOH).TheIRspectrumexhibitedabsorptionbandsduetohydroxyl(3435cm-'),Ylactone(l764cm-')anddoublebond(l648,l635,l456cm-')groups.Themolecularformu1aCstheooof1wasdeducedfromthedataofESIMS(Inlz5l9[M Na] ,53…     

天然黄酮类化合物清除羟基自由基的活性研究

采用分光光度法测定了黑沙蒿中黄酮类化合物清除羟基自由基的能力,以IC50值作为评价指标,初步探讨了黄酮类化合物清除羟基自由基的活性与结构之间的关系,为开发利用黑沙蒿提供了科学依据.     

New Guaipyridine Sesquiterpene Alkaloids from Artemisia rupestris L.

Three new guaipyridine sesquiterpene alkaloids, rupestine A, B, C ( 1 – 3 , resp.), and the new nor‐sesquiterpne alkaloid rupestine D ( 4 ) were obtained from the flowers of Artemisia rupestris L. Their structures were elucidated on the basis of sepectroscopic data and by comparison with those of the related compounds reported in the literature. In addition, the absolute configurations of 2 and 4 were determined by single‐crystal X‐ray diffraction analyses.     

Identification and Biological Activity of Volatile Organic Compounds Emitted by Plants and Insects. IV. Composition of Vapor Isolated from Certain Species of Artemisia Plants

The components of fragrance from four wormwood species of theArtemisiaL. genus were analyzed by GC-MS. The major and minor components of volatile essential oils typical of the studied plant species were determined.     

蒿属三种药用植物营养器官的解剖学研究

本文对大籽蒿、野艾、椒蒿的营养器官进行了组织形态学的观察.分析了药用植物的解剖学特征与药用成份的贮藏、运输和分泌的关系.并总结出这三种植物的茎与叶的显微结构特征可做为鉴别不同种和药材真伪的依据.     

短穗柽柳花内蜜腺的解剖学研究

短穗柽柳的花内蜜腺位于花冠基部与子房之间的花盘上,属于花盘蜜腺。蜜腺组织由分泌表皮、产蜜组织以及维管束三部分组成。分泌表皮具有较厚的角质层,但其上没有气孔器分布,产蜜组织在蜜腺发育过程中,其液泡和淀粉粒随蜜腺的发育有一定的消长规律。来自花托的维管束一直通入产蜜组织内。维管组织中只有韧皮部,原蜜汁可能由韧皮部提供。     

Synergistic antinociceptive activity of combined aqueous extracts of Artemisia campestris and Artemisia herba-alba in several acute pain models

In this study, total phenolic and flavonoid contents, acute toxicity and the antinociceptive activity of Artemisia campestris and Artemisia herba-alba, individually and in combination, were investigated using multiple forms of pain in animals. Our results have been shown that plants are relatively safe without clinical signs of toxicity in animals. Thus, extracts were presented high levels in phenolic and flavonoid contents. Artemisia decoctions with 100, 200, 400 mg/kg b-w studied dose, clearly attenuate chemical and thermal noxious stimuli in writhing, formalin and hot-plate tests, and significantly reduced paw oedema in formalin test. Additionally, binary combination forms exhibited a great improvement in intensity and amplitude of antinociceptive activity in comparison with both plants used individually by a relative interference with opioid system. Our findings suggested the central and peripheral analgesic properties and confirmed the folkloric medicinal use of these plants in pain symptom treatment.