CARBON-14 LABELING AND BIOLOGICAL ACTIVITY OF THE TUMOR-LOCALIZING DERIVATIVE OF HEMATOPORPHYRIN

Abstract— Carbon-14-labeled hematoporphyrin ([¹⁴C]HP) was synthesized by two methods, (i) Using an in vitro avian whole-blood system, [¹⁴C]protoheme was obtained biosynthetically by incorporating [⁴C]aminolevulinic acid into the porphyrin ring structure. Subsequently, the [¹⁴C]protoheme was converted to [⁴C]HP by standard procedures, (ii) By adopting several well-characterized chemical reactions, deuteroporphyrin was treated with [¹⁴C]acetyl chloride, giving [¹⁴C]diacetyl deuteroporphy-rin which was readily reduced and hydrolyzed to [¹⁴C]HP (with thecarbon–14 label on the hydroxyethyl side-chains). These two methods are simple and afford good yields of [¹⁴C]HP with moderate to high specific activities. The [¹⁴C]HP was then treated with acetic acid/sulfuric acid followed by sodium hydroxide to give [¹⁴C]HPD. Upon gel- and ultra-filtration, the [¹⁴C]HPD was enriched in the so-called tumor-localizing fraction of HPD, giving [¹⁴C]PII with specific activities of 0.4 Ci/mol (biosynthesis) and 10 Ci/mol (chemical synthesis). These [¹⁴C]PII preparations were equivalent with respect to chromatographic and spectrophotometric characteristics, as well as tumoricidal photodynamic activity in the DBA/2 Ha-DD mouse: SMT-F tumor system, to the unlabeled commercial product Photofrin^? II. The distribution of [¹⁴C]PII in mouse tissues was in close agreement to that previously reported, after adjustment for dose, for [¹⁴C]HPD biosynthetically labeled in vivo (Gomer and Dougherty, 1979), as well as for Photofrin^? II, where tissue levels were determined spectrophotometrically after extraction (Dougherty and Mang, unpublished).     

Reactions of bis(cyclopentadienyl)titanium(IV) and zirconium(IV) chlorides with 1,1′-diacetylferrocenyl bis(hydrazones). Formation of trimetallic derivatives

Bis(cyclopentadienyl)titanium(IV) and zirconium(IV) chlorides react with bis(hydrazones) derived from 1,1-diacetylferrocene in anhydrous THF in the presence of base to give complexes of the type [(Cp₂MCl)₂L] [M = Ti or Zr; LH₂ = ferrocenyl bis(hydrazones)]. Tentative structures are proposed for these complexes based upon elemental analyses, electrical conductance, magnetic moment and spectroscopic data.     

Xanthan gum production from cassava bagasse hydrolysate with Xanthomonas campestris using alternative sources of nitrogen

Cassava bagasse was hydrolyzed using HCl and the hydrolysate was used for the production of xanthan gum using a bacterial culture of Xanthomonas campestris. Cassava bagasse hydrolysate with an initial concentration of approx 20 g of glucose/L proved to be the best substrate concentration for xanthan gum production. Among the organic and inorganic nitrogen sources tested to supplement the medium—urea, yeast extract, peptone, potassium nitrate, and ammonium sulfate—potassium nitrate was most suitable. Ammonium sulfate was the least effective for xanthan gum production, and it affected sugar utilization by the bacterial culture. In media with an initial sugar concentration of 48.6 and 40.4 g/L, at the end of fermentation about 30 g/L of sugars was unused. Maximum xanthan gum (about 14 g/L) was produced when fermentation was carried out with a medium containing 19.8 g/L of initial reducing sugars supplemented with potassium nitrate and fermented for 72 h, and it remained almost the same until the end of fermentation (i.e., 96 h).     

Do aziridines require Lewis acids for cleavage with ionic nucleophiles?

A variety of activated aziridines were cleaved by sodium azide and sodium cyanide in aqueous acetonitrile at reflux, in the absence of any Lewis acid, to provide ring-opened products in quantitative yields. However, the reaction was sluggish in the ring opening of unactivated aziridines with sodium azide where the yields could be increased by adding 50 mol% CuCl₂·2H₂O. The reaction was used to synthesize chiral diamines.     

Donor substrate flexibility study of AtUGT89C1, a glycosyltransferase from Arabidopsis thaliana

AtUGT89C1, a glycosyltransferase from Arabidopsis thaliana, has shown interesting characteristics such as accepting diverse NDP-D/L-sugars as glycosyl donors. Genistein was used as a substrate to probe in vitro reactions in which different NDP-sugars were used as sugar donors. Among nine different NDP-D/L-sugars tested, AtUGT89C1 accepted five of them, including UDP-α-D-glu-cose, UDP-α-D-galactose, dTDP-β-L-rhamnose, GDP-β-L-fucose, and dTDP-α-2-deoxy-D-glucose and conjugated sugar moieties from the respective donors with the 7-hydroxyl position of genistein. Results showed the promiscuous nature of AtUGT89C1 toward donor and acceptor substrates, thus expanding the biotechnological application of this enzyme in the production of natural and unnatural flavonoid glycosides.     

Intra-Specific Chemotypic Variability of Forskolin Content in Coleus forskohlii (Wild.) Briq. Growing in Nilgiri Hills of India

JPC – Journal of Planar Chromatography – Modern TLC - Plant metabolite varies with season and geographic conditions. The present study is aimed at the identification of the potential...     

Transition from antagonistic to synergistic interaction in mixed micellar system by increase in alkyl chain length of alkyl trimethylammonium bromide

Herein, the electrical conductivity technique used to measure the critical micelle concentration (cmc) for pure cationic surfactants (Dodecyl/cetyltrimethylammonium bromides) and phenothiazine drug (Promethazine hydrochloride), as well as their different mole fractions in 10^?3 ?mol/kg 1-methyl-3-octylimidazolium chloride (C₈mim.Cl) at different temperatures. By using the cmc values the regular solution theory used to evaluate the micellar mole fraction for DTAB/CTAB-PMT mixed systems. The clint's model used to calculate the ideal critical micelle concentration (cmc1) that helps to evaluate the ideal micellar mole fraction for studied mixed systems, both explain the deviation from ideality. In addition, interaction parameter β^m helps to confirm the nature of interaction (either antagonistic or synergistic) for the studied systems. The calculated parameters confirm a transition in the binding nature from antagonistic to synergistic with the increase in alkyl chain length of cationic surfactant i.e., component of the binary mixed system. The ease of micellization for the studied systems discussed by the standard Gibb's energy of micellization ($\Delta G_m^0$), as well as the standard enthalpy and standard entropy of micellization were ($\Delta H_m^0$) and ($\Delta S_m^0$), respectively to discuss the stability of the studied systems.