A study of the acid-base transformations of oxodihydrothiochrome

The acid-base properties of oxodihydrothiochrome — the product of the redox disproportionation of the vitamin B₁ catabolite thiochrome (pH=10.7, 4.5, and 0.5) — have been studied in the pH interval of 0–12 by PMR spectroscopy. It has been established that in acid medium (pH 0–1) the formation of a doubly charged ion is accompanied by a further structural transformation of the molecule of (I) with the formation of a vitamin B₁ analogue — oxothiamine (II). A possible mechanism of the action of (I) as an inhibitor of thiamine-dependent enzymes is discussed in the light of the results obtained. Details of the PMR spectra of (I) and (II) are given.     

Komplexbildung des Hydroxycobalamins mit Kaliumhexacyanoferrat(II)

Zusammenfassung Das Hydroxycobalamin bildet mit Kaliumhexacyanoferrat(II) bei pH 2,5–2,7 ein wasserlösliches Derivat [B₁₂-Fe(CN)₆-B₁₂]^2–, das einen Komplex mit einer Bildungskonstante lgK=10,00±0,04 darstellt. Der Komplex ist reaktionsfähig und wird leicht in andere Derivate des Vitamins B₁₂ übergeführt.

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Complex Formation of hydroxycobalamin with potassium hexacyanoferrate(II)

Hydroxycobalamin forms with potassium hexacyanoferrate(II) at pH 2.5–2.7 a water soluble complex [B₁₂-Fe(CN)₆-B₁₂]^2– with a formation constant lgK=10.00±0.04. The complex has high reactivity and easily can be converted into other derivatives of vitamin B₁₂.

     

Alkaloids ofAconitum coreanum. I. Structure of acorine

Two C₂₀-diterpene alkaloids have been isolated from the epigeal part ofAconitum coreanum (Levl.) Rapaics: the known 14-hydroxy-2-isobutyrylhetesine (I) (Guan-Fu base Z) and a new one — acorine (II), C₂₂H₂₉NO₅, mp 214–215°C (from acetone), _D ²⁰ +9° (c 0.01; methanol), for which the structure of 2-acetyl-14-hydroxy-hetesine has been established. Details of the IR, mass, and¹³C NMR spectrum of (I) and (II) and of the PMR spectrum of (II) are given.Institute of the Chemisry of Plant Substances of the Uzbek Academy of Sciences, Tashkent. All Union Scientific-Research Institute of Medicinal Plants. Translated from Khimiya Prirodnykh Soedenenii, No. 5, pp. 690–692, September–October, 1987.     

Pheromones of insects and their analogs

Dodec-8Z-en-1-ol (VIII) and tetradec-8Z-en-1-ol (IX) and the corresponding acetates (X and IX) — components of the sex pheromones of many species of Lepidoptera — have been synthesized from cyclooctene (I) in three stages. The ozonolysis of (I) (–70°C, CH₂Cl₂-MeOH, NaHCO₃; –20°C, Ac₂O/Et₃N) led to methyl 8-oxooctanoate (II). The DNPH of (II), (III), mp 59–61°C. The coupling of (II) with n-C₃H₁₇ CH=PPh₃ (IV) or with n-C₅H₁₁ CH=PPh₃ (V) (–70°C, 2 h; 25°C, 15 h, Ar) gave the methyl esters of dodec-8Z-enoic (VI) and tetradec-8Z-enoic (VII) acids, respectively. The reduction of (VI) and (VII) [(i-Bu)₂AlH, 0°C, 2 h; 25°C, 15 h] gave the corresponding alcohols (VIII) and (IX) by the acetylation (Ac₂O-Py, 25°C, 24 h) of which, (X) and (XI), were obtained. The yields (%): (II) 80, (VI) 45, (VII) 60, (VIII) 95, (IX) 90, (X) 75, (XI) 74. The IR and PMR spectra of compounds (II) and (VI–XI) are given.Institute of Chemistry, Bashkir Scientific Center, Urals Branch, Academy of Sciences of the USSR, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 276–279, March–April, 1989.     

Copper(II)–1,2-bis(thiocarbamoyl)hydrazine and copper(II)–(1-carbamoyl-2-thiocarbamoyl)hydrazine complexing in copper(II)hexacyanoferrate(II) gelatin-immobilized matrix systems

The complex formation that occurs in gelatin-immobilized copper(II)hexacyanoferrate(II) matrices upon contact with aqueous alkaline (pH 12.0) solutions of 1,2-bis(thiocarbamoyl)hydrazine, H₂NC(S)NHNHC(S)NH₂ and 1-carbamoyl-2-(thiocarbamoyl)hydrazine, H₂NC(O)NHNHC(S)NH₂ has been studied. The reaction of each of these ligands with copper(II) is preceded by the destruction of copper(II)hexacyanoferrate(II) in an alkaline medium to form a polymeric copper(II) hydroxide, which is involved in the subsequent copper(II)–ligand complex formation. In both Cu^II–N ligand systems, two complex compounds are formed; the water-insoluble Cu₂B₂(H₂O)₂ dimer and a water-soluble product of tentative composition [CuB(HB)]^– (H₂B=ligand).     

Electron transfer: 150. The reaction of corrin-bound cobalt(III) with indium(I) — an additional mechanistic variation

(Corrin)cobalt(III) is reduced by indium(I) to its Co(II) counterpart (cob(II)alamin, B_12r) at pH 1-2 in aqueous chloride. In these solutions the aqua oxidant (B_12a) is in mobile anation equilibrium with its chloro derivative. At [Cl^–] 0.03 M, consumption of Co(III) is exponential and proceeds by parallel paths involving the aqua- and chloro-substituted oxidants. At [Cl^–] 0.10 M, rates are governed mainly by an preliminary act requiring In(I) and 2 Cl^–, but no Co(III). This initiation step generates a more reactive In(I) species which is taken to result from a slow heterolysis and loss of ligating water from InCl₂ ^–(aq).     

Insect pheromones and their analogues. XVI. Practical synthesis of hexadec-9Z-enal — A component of the sex pheromone of the cotton bollwormHeliothis armigera

A synthesis of hexadec-9Z-enal — a component of the sex pheromone of the cotton boll-wormHeliothis armigera (Hübner) — based on cyclooctene (I) is proposed. Through a solution of 22 g of (I), 250 ml of cyclohexane, and 40 ml of MeOH is passed (at 5°C) 0.2 M O₃/O₂, the solution is decanted off, and the precipitated ozonide is dissolved in 200 ml of MeOH and is reduced with 19 g of NaBH₄ (40°C) with the isolation, after the usual working up, of 23.4 g of octane-1,8-diol (II). From 0.5 mole of (II) and 0.6 mole of 45% HBr 8-bromooctan-1-ol (III) is obtained and this is converted into 1-(2-THPL)oxy)-8-bromooctane (IV). The condensation of (IV) with oct-1-yne (Ar, LiNH₂, HMPTA, 10°C, 1 h, and then 55°C, 10 h) leads to 1-(2-THPL-oxy)hexadec-9-yne (V) the hydrolysis of which (MeOH, H₂O, p-TsOH, 20°C for 20 h) yields hexadec-9-yn-ol (VI). The reduction of (VI) (Et₂O, iso-BuMgBr, Cp₂TiCl₂, 0°C, 15 min, then 20°C, 1 h) yieldshexadec-9Z-en-l-ol (VII). The oxidation of (VII) (PyHCrO ₃ ⁺ Cl^–, CH₂Cl₂, 20°C, 2 h) gives hexadex-9Z-enal (VIII). Characteristics of the compounds (yield (%), n _D ^{20 (25)}: (II) – 80, mp 61–62°C; (III) – 75, 1.4807; (IV) – 99, —; (V) – 52, 1,4650; (VI) – 85, 1.4657; (VII) – 99, 1.4650; (VIII) – 98, 1.4600. Characteristics of the IR and PMR spectra of compounds (V–VII) are given.Institute of Chemistry, Bashkir Branch, Academy of Sciences of the USSR, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 286–289, March–April, 1987.     

Structure of aerugine from Pseudomonas aeruginosa

A new optically active phenolic alkaloid with the composition C₁₀H₁₁NO₂S, mp 85–88°C, []_D +28° (c 1.0; chloroform) (I) has been isolated from the microorganismPseudomonas aeruginosa (strain 590) and has been called aerugine. The action of diazomethane gave an O-methyl derivative (II). On the basis of the formation of ortho-cresol by the hydrogenolytic desulfuration reaction, a study of the IR, mass, and PMR spectra and (I) and its acetyl derivative (III), and also the¹³C NMR spectrum of (I), the structure of 4-hydroxymethyl-2-(o-hydroxyphenyl)-2-thiazoline has been established for aerugine. The spectral characteristics of the compounds mentioned are given.Institute of the Chemistry of Plant Substances of the Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 553–558, July–August, 1987.     

An investigation by the NMR method of the structure of the alkaloid sophorine fromSophora alopecuroides

A new base — sophorine, with mp 59–60°C, [] _D ²³ -18.9° (c 0.98; ethanol) — has been isolated from the epigeal part of the plantSophora alopecuroides L. Its IR spectrum and the nature of its mass spectrometric composition have permitted sophorine to be assigned to the quinolizidine alkaloids. The¹³C NMR spectrum has shown the presence of 19 carbon atoms. The analysis of several of the carbon signals has confirmed the results of IR and mass spectroscopy. Additional details of the structure of sophorine have been obtained from its PMR spectrum.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 604–608, September–October, 1981.     

Phytoecdysteroids of plants of the genus Silene. XVI. Viticosterone E 22-O-benzoate from Silene wallichiana

A new phytoecdysteroid, viticosterone E 22-O-benzoate (I), C₃₆H₅₀O₀, mp 147–149°C (methanol-water), [] _D ²⁰ +63.2° (methanol), has been isolated from the epigeal organs ofSilene wallichiana Klotzsch. The alkaline hydrolysis of (I) led to viticosterone E and benzoic acid. The acetylation of (I) gave the 2,3-diacetate (II), C₄₀H₅₄O₁₁, mp 152–153°C (methanol-water), [] _D ²⁰ +65.5° (methanol). Details of the IR, PMR, and mass spectra of (I) and (II) are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 546–549, July–August, 1988.     

O-acylated flavonoid glycosides from the needles ofPicea obovata II. 3′- and 6′-isomers of p-coumaroylastragalin

Two monoacylated glycosides have been isolated from the needles ofPicea obovata — the previously unknown 3-p-coumaroylastragalin (I) and 6-p-coumaroylastragalin (II). It has been established that under the conditions of mild saponification and acid hydrolysis isomerization of (I) into (II) and the splitting out of the acy1 residue takes place. The position of the acy1 substituent has been shown by PMR spectroscopy using the INDOR method. The physicochemical characteristics of the acylated glycosides and of their heptaacetates are given.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Irkutsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, Moscow. I. M. Sechenov First Moscow Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 186–190, March–April, 1980.     

Influence of the linking chain length on the recombination kinetics of covalently bonded triplet radical pairs and magnetic field effects

Nanosecond laser flash photolysis technique is used to study the formation and decay kinetics of covalently linked triplet radical pairs (RP) formed after photoinduced electron transfer in the series of 21 zinc porphyrin—chain—viologen (Pph—Sp_n—Vi²⁺) dyads, where the number of atoms (n) in the chain increases from 2 to 138. In poorly viscous polar solvents (acetone, CHCl₃—CH₃OH (1 : 1) mixture), the dependence of the rate constant of RP formation on n can be described by the equation k _e = k _e ⁰ n ^–a at k _e ⁰ = 2.95·10⁸ s^–1 anda = 0.8. In the zero magnetic field, the RP recombination rate constant (k _r(B = 0)) is significantly lower than k _e and ranges from 0.7·10⁶ to 8·10⁶ s^–1. The dependence of k _r(B = 0) on n is extreme. The dependence k _r(B = 0) reaches a maximum at n = 20. In the strong magnetic field (B = 0.21 T), the significant retardation of triplet RP recombination is observed. The chain length has an insignificant effect on k _r(B = 0.21 T), which ranges from 0.3·10⁶ to 0.9·10⁶ s^–1. The regularities found are discussed in terms of the interplay of molecular and spin dynamics.     

Physalis withanolides II. Withaphysanolide

A new withanolide with the composition C₂₈H₃₈O₇, which has been called withaphysanolide (I) has been obtained from a chloroform extract of an aqueous extract of the epigeal part ofPhysalis viscosa L. On the basis of a study of the UV, IR, PMR, and mass spectra of (I) and the products of the oxidation of its acetate (II) — a lactone C₉H₁₂O₃ (III) and 4-acetoxy-5-hydroxy-1,17-dioxoandrosta-2,8(14)-diene (IV) — the structure of 4,5,17,20-tetrahydroxy-l-oxo-22R-witha-2,8(14),24-trienolide is suggested for (I).Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 214–217, March–April, 1980     

Structure of zangezurine

A new base with []_D +208° (c 0.7; methanol) has been isolated from the combined nonphenolic alkaloids ofPapaver zangezuricum A. D. Mikheev, and has been called zangezurine (I). The acetylation of (I) with acetic anhydride in pyridine yielded O-acetylzangezurine (II). The structure of zangezurine has been established on the basis of the UV, IR, mass, PMR, and¹³C NMR spectra of (I) and (II).Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Pyatigorsk Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 858–862, November–December, 1987.     

Pheromones of insects and their analogs. XX. Methyl-branched pheromones based on 4-methyltetrahydropyran.

A synthesis is proposed of 4,8-dimethyldecanal (VIII) — a pheromone of the flour beetlesTribolium confusum andT. castaneum. By heating 71.2 g of 4-methyltetrahydropyran (I), 83.2 g of AcBr and 1.57 g of ZnCl₂ (45°C), then 120°C, 2 h), 1-acetoxy-5-bromo-3-methylpentane (II) was obtained. The hydrolysis of 19.8 g of (II) (MeOH-H₂O, TsOH, 20°C, 15 h) gave 5-bromo-3-methylpentan-1-ol (III). From 18.1 g of (III) and 38.9 ml of 2,3-dihydropyran (Et₂O, TsOH, 20°C, 20 h) was obtained the 2-THPL ester of (III), (IV), which was converted into 3-methyloct-7-en-1-ol (V) by the treatment of the corresponding Grignard reagent with allyl bromide (THF, CuI-bi-2-pyridyl, 2°C, 4 h, Ar). The interaction of 1.42 g of (V) with Et₃Al (hexane, 20°C, Cp₂ZrCl₂, Ar) gave 3,7-dimethylnonan-1-ol (VI), boiling which with 48% HBr in the presence of concentrated H₂SO₄ gave 1-bromo-3,7-dimethylnonane (VII) which was then converted into the desired (VIII) by the reaction of the corresponding Grignard reagent with DMFA (0–2°C, 1 h; 20°C, 2 h; Ar). The characteristics of the compounds — yield (%), n_D (°C): (I), 79, 1.4340 (22); (III) 89, 1.4660 (23); (IV), 82, 1.4739 (23); (V), 85, —; (VI), 90, 1.4483 (20); (VII), 88, 1.4409 (22); (VIII), 88, 1.4589 (22). Details of the IR and PMR spectra of compounds (II)–(VII) are given.Institute of Chemistry, Bashkir Scientific Center, Urals Branch, USSR Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 272–276, March–April, 1989.     

Mode of formation of some rare copper(II) and lead(II) minerals from aqueous solution,with particular reference to deposits at tiger,Arizona

Summary Free energies of formation of the rare copper(II) secondary minerals linarite, (Pb,Cu)₂SO₄(OH)₂, caledonite, Pb₅Cu₂CO₃(SO₄)₃(OH)₆, and wherryite, Pb₄CuCO₃(SO₄)₂O(OH,Cl)₂, and of the complex lead(II) species leadhillite, Pb₄SO₄(CO₃)₂(OH)₂, have been estimated using solution techniques. Values derived are: –1212(1), –4328(2), –2871(1), and –2525(4) kJ mol^–1 at 298.2K respectively, and have been used to construct stability field diagrams involving these, and related species. They are anomalous in the sense that they are not the usually found sulphates and carbonates of copper(II) and lead(II) in the natural environment. The data, together with field observations of mineral associations, has been used to reconstruct part of the chemical paragenetic sequence of the oxidized zone of the Mammoth —St. Anthony Mine, Tiger, Arizona, U.S.A. Many of the rare species above and other complex halides of copper(II), silver(I) and lead(II) formed under conditions where and a_{SO 4} ^2– were comparatively low, and around neutral values of pH. Several trends in the chemistry of the development of the anomalous oxidized zone at Tiger are apparent, and these are discussed in the light of the above findings.     

Phytoecdysones ofSilene praemixta. II. Premixisterone

The structure of premixisterone (I) — a new ecdysteroid fromS. praemixta M. Pop. (Caryophyllaceae) — has been established. Compound (I) has the composition C₂₇H₄₄O₅, mp 110–112°C (from C₂H₅OH + H₂O), [] _D ²⁴ 0 ± 4° (c 0.85; MeOH), 202 nm (log 3.35), _max ^KBr 3415 cm^–1 (OH), 1710 cm^–1 (C=0), and does not contain the ⁷-6-keto grouping that is characteristic of natural ecdysteroids. The acetylation of (I) with (CH₃CO)₂ in Py gave the amorphous 3,22-diacetylpremixisterone (II), C₂₁H₄₈O₇. Compound (I) has the structure of 3,14,22R,25-tetrahydroxy-5-cholest-8-en-6-one. The IR, PMR, and mass spectra of (I) and (II) are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 797–799, November–December, 1979.     

Benzo[f]-3-aza- and -10-azafluoroanthenes

Reduction of 3-methyl-9-(o-tolyl)-2-azafluoren-9-ol (I) with tin in hydrochloric acid gave 3-methyl-9-(o-tolyl)-2-azafluorene, dehydrocyclization of which on a K-16 catalyst at 520–500°C gave a complex mixture, from which four substances — 2-methylbenzo[f]-3-azafluoranthene, 11-methylbenzo[f]-10-azafluoranthene, benzo[f]-3-azafluoroanthene (II), and I-were isolated and identified by means of the IR, UV, and PMR, and mass spectra. It is shown that the dehydrocyclization proceeds through the hydrogen atoms of the methyl group of the tolyl substituent and takes place at the 8-C or 1-C atom of the azafluorene system. The formation of products II and I constitutes evidence that the reaction is accompanied by partial demethylation or oxidation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1245–1247, September, 1977.