€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€ *****ACTA VIROLOGICA***** Petrzik K Physicochemical properties of four tymoviruses. In: Acta Virol (1993 Aug) 37(4):271-5 ISSN: 0001-723X Isoelectric point (pI), free mobility and retardation coefficient (KR) of turnip yellow mosaic virus (TYMV), erysimum latent virus (ELV), belladonna mottle virus (BelMV) and scrophullaria mottle virus (ScrMV) have been studied. The use of Ferguson plots for the physical identification of these four viruses and for confirmation of their identity is discussed. For TYMV, ELV, BelMV and ScrMV the pI values of 3.64, 4.73, 6.25 and 3.95, respectively, were found. Using KR the differences between the diameter of particles of the four tymoviruses were estimated. The particle diameter decreases as follows: ELV, ScrMV, TYMV, BelMV. €€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€ *****ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY***** Huang ZZ Wu L Species richness and selenium accumulation of plants in soils with elevated concentration of selenium and salinity. In: Ecotoxicol Environ Saf (1991 Dec) 22(3):251-66 ISSN: 0147-6513 Field studies were conducted in soils with elevated concentrations of Se and salinity at Kesterson, California. Biomass distribution, species richness, and selenium accumulation of plants were examined for two sites where 15 cm of surface soil was removed and replaced with fill dirt in the fall of 1989, and two sites were native soil cover. The Se concentrations in the top 15 cm of fill dirt ranged from undetectable to 36 ng g-1. For the native soil sites, Se levels ranged from 75 to 550 ng g-1. Soil Se concentrations below 15 cm ranged from 300 to 700 ng g-1 and were comparable between the fill dirt and the native soil sites. At least 20 different plant species were brought into the two fill dirt sites with the top soil. Avena fatua L., Bassia hyssopifolia Kuntze Rev. Gen. Pl., Centaurea solstitialis L., Erysimum officianale L., Franseria acanthicarpa Cav. Icon., and Melilotus indica (L.) All. contributed over 60% of the total biomass. Only 5 species were found in the native soil sites, and salt grass (Distichlis spicata L.) was the predominant species and accounted for over 80% of the total biomass. Between 1989 and 1990, two years after the surface soil replacement, the two fill dirt sites had a 70% reduction in species richness. Plant tissue selenium concentrations were found to be quite variable between plant species and between sites of sampling. At the fill dirt sites, the plant species with deep root systems accumulated greater amounts of selenium than the shallow-rooted species. The soil selenium concentration of the field soil had no negative effect on pollen fertility, seed set, and seed germination for the plant species examined. However, seedling growth was impaired by the soil selenium concentrations. This suggests that a selection pressure of soil Se concentration may have been imposed on plant species such as M. indica in an early stage of its life cycle. Registry Numbers: 7647-14-5 (Sodium Chloride) 7782-49-2 (Selenium) €€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€ *****JOURNAL OF NATURAL PRODUCTS***** Piatak DM Tang PF Sorensen PD Srensen PD Constituents of Erysimum inconspicuum. Two sulfur-containing lactone compounds. In: J Nat Prod (1985 May-Jun) 48(3):424-8 ISSN: 0163-3864 The alcohol extract of Erysimum inconspicuum fruits, which exhibited cytotoxic activity against the KB cell line and some activity against the P-388 lymphocytic leukemia in vivo, was studied. Strophanthidin, uzarigenin, and two sulfur-containing lactones, erysulfone[6- methylsulfonyl-4-hydroxyhexanoic acid lactone] and erysulfoxide[6- methylsulfinyl-4-hydroxyhexanoic acid lactone], were isolated and characterized by spectral data. Registry Numbers: 66-28-4 (Strophanthidin) 98043-36-8 (erysulfone) 98043-37-9 (erysulfoxide) €€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€ *****NUCLEIC ACIDS RESEARCH***** Hellendoorn K Michiels PJ Buitenhuis R Pleij CW Protonatable hairpins are conserved in the 5'-untranslated region of tymovirus RNAs. In: Nucleic Acids Res (1996 Dec 15) 24(24):4910-7 ISSN: 0305-1048 The secondary structures of the 5'-untranslated region (5'-UTR) of five different tymoviruses have been determined by structure probing, computer prediction and sequence comparison. Despite large sequence differences, there are remarkable similarities in the secondary structure. In all viruses two or four hairpins are found, most of which contain a symmetrical internal loop consisting of adjacent C-C or C-A mismatches. Since it is known that such mismatches can be protonated and protonated cytosines play an important role in RNA- protein interactions in tymoviral virions, the influence of pH on the conformation of the internal loop was studied. UV melting experiments and 1-dimensional proton NMR at varying pH values and salt concentrations confirm that the hairpins can be protonated under relatively mild conditions. The hairpin found in the 5'-UTR of erysimum latent virus, which has an asymmetrical internal loop consisting of cytosines and uridines, shows comparable behaviour. It is concluded that all tymoviral RNAs contain protonatable hairpins in the 5'-UTR. Binding experiments with empty viral capsids, however, do not yet establish a role in capsid protein binding. €€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€ *****PHYTOCHEMISTRY***** Lei ZH Yahara S Nohara T Shan TB Xiong JZ Cardenolides from Erysimum cheiranthoides. In: Phytochemistry (1996 Mar) 41(4):1187-9 ISSN: 0031-9422 Three new cardiac glycosides were isolated along with two known cardenolides from the seeds of Erysimum cheiranthoides. The new ones were characterized by spectral methods as 16 beta- hydroxystrophanthidin (strophadogenin) 3-O-beta-glucopyranosyl-(1-- >4)-beta-boiviopyranoside, strophadogenin 3-O-alpha-rhamnopyranosyl- (1-->4)-beta-digitoxopyranoside and strophanthidin 3-O-alpha- rhamnopyranosyl-(1-->4)-beta-digitoxopyranoside, named cheiranthosides I, II and III, respectively. €€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€