Alkaloids of Vinca major

Summary 1. From the epigeal part ofVinca major have been isolated the known bases akuammicine, vincamajine, vincamajoridine, and ervine, and the new alkaloid majorinine with the composition C₂₂H₂₄N₂O₄, mp 195–196°C.2. On the basis of chemical transformations and IR, UV, mass, and PMR spectra using the methods of double resonance collapse and INDOR the structure of 21-hydroxy-10-methoxyvinorine and the stereochemistry (I) have been established for majorinine.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 382–387, May–June, 1977.     

Vinervine — A new alkaloid from the aboveground part of Vinca erecta RGL. ET schmalh

Summary From the aboveground part ofV. erecta gathered in the Shargun' settlement in the Surkhan-Darya region 1% of total alkaloids was isolated, and in the separation of these the bases vincanidine and a new phenolic base vinervine (C₂₀H₂₂O₃N₂) were obtained. Vinervine is an alkaloid of the 2-methyleneindoline group.Translated from Izvestiya Akademii Nauk SSSR, Khimicheskaya, No. 12, pp. 2152–2155, December, 1965     

Influence of solvents on the parameters of the NMR spectra of Vinca alkaloids. V

Summary On the basis of the results of a study of the influence of various solvents on the parameters of the NMR spectra of some hydroxyindole alkaloids, the following characteristic values of for the protons have been found:a) for C₁₉-CH₃ in the allo bases is +0.18 ppm; b) in the epiallo bases it is +0.36 ppm; c) for CO₂CH₃ in the allo bases is +0.30 to +0.37 ppm; d) in the epiallo bases it is +0.19 ppm; and e) for the 11-OCH₃ group in the hydroxyindoles is +0.44 to +0.52 ppm.It has been established that in the epiallo bases benzene causes a diamagnetic shift, and in the allo bases a paramagnetic shift, of the H₁₉ signal. It is possible to perform a stereochemical identification of the hydroxyindole alkaloids on the basis of the value of for C₁₉-CH₃, CO₂CH₃, and H₁₉ protons.Analysis of the signals of the aromatic protons of vineridine in C₆D₆ solution and in a number of other solvents has permitted their assignments to be refined and a long-range (allyl) coupling of the H₁₇ and H₁₅ protons with an SSCC of 2.0 Hz that is characteristic of the epiallo alkaloids to be found. It has been shown that the change in the CSs of the protons of rings D and E of the hydroxyindole alkaloids and the indole alkaloid reserpinine as a result of the influence of various solvents mainly has a symbatic nature. The invariability of the SSCCs of the protons in the solvents investigated with the exception of solutions in TFA, shows that the conformations of rings C, D, and E in them do not change. The changes in the CSs and SSCCs of the protons in the alkaloids investigated in TFA are an indication of the isomerization of these compounds in the acid.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 360–368, May–June, 1977.     

Vince alkaloids XXXIV). Preparation of des-Na-methyl-vindoline by microbiological conversion of vindoline, a major alkaloid from Vinca rosea L

The conversion of vindoline (II) using S. albogriseolus led to the isolation of several compounds including des-N_a-methyl vindoline (III) in 8–10% yield.     

Vinca alkaloids XXXIII [1]. Microbiological conversions of vincaleukoblastine (VLB, vinblastine), an antitumor alkaloid from Vinca rosea. Linn

The conversion of VLB using different Streptomycetes led to the isolation of VLB-ether ( 3 ) and Hydroxy VLB ( 6 ). The structural assignments have been made by NMR. and high resolution mass spectral data.     

Polysulfonylamines. CXXXII.

The crystal structure of the title compound, C₅H₇N₂⁺·C₁₂H₁₀NO₄S₂⁻, consists of two independent cation–anion pairs, A and B. Within each pair, the H—N—C—N*—H grouping (N*—H is the pyridinium function) and one N—S—O moiety of the anion are linked by N*—H⃛N and N—H⃛O hydrogen bonds to form an antidromic ring motif of type R²₂(8). The remaining amino donors give rise to N—H⃛O hydrogen bonds, connecting the ion pairs into A–B–A–B– chains. The structure testifies to the persistence of the R²₂(8) motif in question, which was previously detected as a highly robust supramolecular synthon in a series of onium di(methane­sulfonyl)­amidates. The structure is pseudosymmetric; the anion positions correspond to space group P2₁/n, but those of the cations do not.     

Thermodynamic Studies of Bi-Univalent Electrolytes. VI. Thermodynamics of Cadmium Acetate from E. M. F. and Calorimetric Measurements

E. M. F. of the Cell, Cd-Hg (2-phase)/CdAc₂(m), Hg₂Ac₂(s)/Hg was measured at 20°, 25°, 30° and 40°C. The standard e. m. f. of the cell, Cd/CdAc₃(m), Hg₂Ac₂(c)/Hg was evaluated as E°=1.1500?11.09×10^?4T+1.06×10^?8T² The thermodynamic data of the reaction, Cd(c) + Hg₂Ac₂(c)=2Hg(l)+Cd⁺⁺(aq)+2Ac^?(aq) at 25°C were estimated as ΔF°=?42,139, ΔH°=?48,698 cal mole^?1 and ΔS°=?22.0 cal deg^?1 mole^?1 at 25°C. The thermodynamic data for the formation of Hg₂Ac₂(s) were evaluated as ΔF_f°=?202.3, ΔH_f°=?154.5 Kcal mole^?1 and S°=72.9 cal deg^?1 mole^?1. From measurements of the heats of solution of CdAc₂·2H₂O in aqueous solution, the relative partial molal enthalpies of cadmium acetate in aqueous solution were estimated.     

Cover Picture: Angew. Chem. Int. Ed. 7/2002

The cover picture shows Cu₂(μ‐O)₂ and Fe₂(μ‐O)₂ complexes with the M₂(μ‐O)₂ diamond core motif (the core is shown bottom right, M=green and oxygen=red spheres) and a representative example of a non‐heme multimetal enzyme (hydroxylase component of methane monooxygenase, in the background). Although quite a familiar feature in high‐valent manganese chemistry, the M₂(μ‐O)₂ diamond core motif has only recently been found in synthetic complexes for M=Cu or Fe. Despite differences in electronic structures that have been revealed through experimental and theoretical studies, Cu₂(μ‐O)₂ and Fe₂(μ‐O)₂ cores exhibit analogously covalent metal–oxo bonding, and similar tendencies to abstract hydrogen atoms from substrates. Our understanding of biocatalysis has been enhanced significantly through the isolation and comprehensive characterization of the Cu₂(μ‐O)₂ and Fe₂(μ‐O)₂ complexes. In particular, it has led to the development of new mechanistic notions about how non‐heme multimetal enzymes, such as, methane monooxygenase, fatty acid desaturase, and tyrosinase, may function in the activation of dioxygen to catalyze a diverse array of organic transformations. To find out more see the review by L. Que, Jr. and W. B. Tolman on p.1114 ff.     

E.S.R. and D.S.C. investigations of phase transitions in polymorphic 4-n-alkoxybenzylidene-4′-n-alkylanilines

Abstract

It is shown that the McMillan parameter M = T _SAN/T _N1 (where T _SAN and T _NI are respectively the temperatures of the smectic A to nematic (SAN) and the nematic to isotropic (NI) phase transitions) is useful in analysing the crossover between second and first order behaviour of the S_NN transition in the nO.m homologous liquid crystal series (the 4-n-alkoxybenzylidene-4′-n-alkylanilines). Using a phase diagram of orientational ordering versus M for this series, as obtained in this work (from E.S.R. and D.S.C), a symmetric tricritical point with mean field exponent β₂ = 1 is demonstrated. In a preliminary study of E.S.R. linewidth parameters B and C of nitroxide spin probes dissolved in members of the nO.m series exhibiting a first order S_AN transition, critical-type divergences are observed near this transition. In the case where M is closer to 0.959 (the value at the tricritical point), these divergences appear similar to those previously observed in related nO.m members with a second order S_AN transition; however, they are considerably enhanced for an M value closer to unity (i.e. more removed from the tricritical point). This indicates the importance of coupling between orientational and positional order parameters in the observed critical-type divergences.     

Triplet excited states of nitronaphthalenes. II. b-Nitronaphthalene

Nanosecond flash photolysis of b-nitronaphthalene (b-NO₂C₁₀H₇) in nonpolar and polar solvents shows a transient species with maximum absorption and lifetime dependent on solvent polarity. In deaerated n-hexane the absorption maximum and lifetime (1/k) are 425 nm and 530 nsec, while in deaerated ethanol the corresponding values are 470 nm and 1.7 ·sec. This transient absorption is attributed to the triplet excited state of b-NO₂C₁₀H₇, and the observed red shift as well as its longer lifetime in polar solvents are indicative of the intramolecular charge transfer character of this state. The change of dipole moment accompanying the transition T₁ → T_n, as well as rate constants for electron and proton transfer reactions involving the T₁ state of b-NO₂C₁₀H₇, were determined. The spectroscopic and kinetic data obtained in this work indicate that the triplet state of b-NO₂C₁₀H₇ behaves like a n-π* state in nonpolar media, while in polar solvents the n-π* character of the state is reduced with a simultaneous increase in the charge transfer character.     

Fluordiazadiphosphetidine, 17. Mitt.

The reactions of (CH₃NPF₃)₂ and F₃P(CH₃N)₂PF₂OCH₃ with lithium-1,1,1-trimethyl-N-(trimethylsilyl)-silanamide yield two new dispiro-compounds:XF₂P(CH₃N)₂PF(NSiCH₃)₂PF(CH₃N)₂PF₂ X withX=F, OCH₃. Synthesis, mass-spectra and X-ray structures are discussed.

Herrn Prof. Dr.K. L. Komarek zum 60. Geburtstag gewidmet.     

Vinmajorines C – E,Monoterpenoid Indole Alkaloids from Vinca major

Three new monoterpenoid indole alkaloids, vinmajorines C–E ( 1 – 3 ), along with 18 known analogues ( 4 – 21 ), were isolated from the whole plants of Vinca major. The new structures were elucidated as (5α,15β,16R,17α,19β,20α,21β)‐10,17‐dimethoxy‐21‐methyl‐18‐oxa‐5,16‐cycloyohimban‐19‐ol ( 1 ), (5α,15β,16R,17α,20α,21β)‐10‐methoxy‐21‐methyl‐18‐oxa‐5,16‐cycloyohimban‐17‐ol ( 2 ), and (5α,15β,16R,17α,20α,21β)‐10‐methoxy‐21‐methyl‐18‐oxa‐5,16‐cycloyohimban‐17‐yl acetate ( 3 ), respectively, by extensive NMR and MS analysis and comparison with known compounds. Compounds 1 – 3 were evaluated for their cytotoxic activities against five human cancer cell lines, compounds 1 and 3 showing moderate cytotoxic activities.     

13C n.m.r. spectra of some polychloroalkenes

¹³C n.m.r. spectra have been measured for thirty-two polychloroalkenes including (i) monosubstituted compounds CH₂?CHCCl_nH_2?nX, where ? X stands for ? H, ? Cl, alkyl, and trisubstituted alkenes CCl₂?CHAlk, none of which form geometric isomers; (ii) disubstituted compounds RCH?CHR′; (iii) and (iv) trisubstituted compounds of the types RCCl?CHR′ and CHCl?CClR, respectively. Compounds (ii) to (iv) represent either individual isomers or mixtures of the Z and E forms. In the case of compounds (ii) and (iii), the ordering of chemical shifts is δ_E > δ_Z for the sp²-carbon atoms and δ_E < δ_z for the adjacent tetrahedral ones. On the contrary, the signals of the sp²-carbon atoms of compounds (iv) obey the rule δ_E < δ_z. The effect of vinyl and allyl groups as substituents on the ¹³C chemical shifts of chlorine-containing groups is discussed. The dependence of the sp²-carbon spin–spin coupling constants J(¹³C? ¹H) on the number of chlorinated substituents in the molecule is also considered.     

Reactivity and gelation. I. Intrinsic reactivity

The method of Case is used with the Flory-Stockmayer gelation criterion to derive a critical transition equation for polycondensation of multifunctional reactants bearing coreactive functional groups of two species A and B, where the B groups may be of unequal intrinsic reactivity. Systems of the types R(A)₂/R′(B)₄ and R(A)₂/R′(B)₄/R′′(B)₂ are considered with the B groups divided into two classes characterized by a reactivity ratio in the range 0.1 to 10. If the reactivities are sufficiently different the polymerization can be regarded as a multistage process. Intramolecular reactions are not considered.     

Planarity of benzoyldithiocarbazate tuberculostatics. II. Diesters of benzoyldithiocarbazic acid

The emergence of drug‐resistant strains of Mycobacterium tuberculosis has intensified efforts to identify new lead tuberculostatics. Our earlier studies concluded that the planarity of a molecule correlates well with its tuberculostatic activity. According to our hypothesis, only derivatives whose molecules are capable of adopting a planar conformation may show tuberculostatic activity. The structures of three new potentially tuberculostatic compounds, namely N′‐[bis(methylsulfanyl)methylidene]‐N‐methyl‐4‐nitrobenzohydrazide (denoted G1), C₁₁H₁₃N₃O₃S₂, N′‐[bis(benzylsulfanyl)methylidene]‐N‐methyl‐4‐nitrobenzohydrazide (denoted G2), C₂₃H₂₁N₃O₃S₂, and N′‐[(benzylsulfanyl)(methylsulfanyl)methylidene]‐4‐nitrobenzohydrazide (denoted G3), C₁₆H₁₅N₃O₃S₂, were determined by X‐ray diffraction. The significant distortion from planarity caused by the methyl substituent at the N atom of the hydrazide group or the NO₂ substituent in the aromatic ring leads to the loss of tuberculostatic activity for G1, G2 and G4 {systematic name: N′‐[bis(methylsulfanyl)methylidene]‐2‐nitrobenzohydrazide}. A similar effect is observed when there are large substituents at the S atoms (G2 and G3).     

Nachweis von Desacetylakuammilin und 10-Methoxy-desacetylakuammilin in Vinca minor L. 147. Mitteilung über Alkaloide

The two indole alkaloids desacetylakuammiline ( 2 ) and 10-methoxy-desacetylakuammiline ( 4 ) were shown to occure in the upper parts of the small periwinkel Vinca minor L. The structure of the hitherto unknown 10-methoxy-desacetylakuammiline was established on the bases of chemical, spectroscopic and o.r.d. evidence.     

Oxazolochlorins. 14.

The structure of 8‐oxo‐5,10,15,20‐tetraphenyl‐7‐oxaporphyrin N²⁴‐oxide, C₄₃H₂₈N₄O₃, (4B), shows that N‐oxidation of the pyrrole opposite the oxazolidone group cants the pyrrole out of the mean plane of the chromophore. This also affects the oxazolidone group, which is also slightly canted out. This conformation is qualitatively similar to that of the parent meso‐tetraphenylporphyrin N‐oxide, but dissimilar to that of the porpholactone N‐oxide isomer 8‐oxo‐5,10,15,20‐tetraphenyl‐7‐oxaporphyrin N²²‐oxide, (4A), carrying the N‐oxide at the oxazolidone group. While the degree of canting of the N‐oxidized groups in both cases is comparable (and more pronounced than in the porphyrin N‐oxide case), in (4A) the pyrrolic groups adjacent to the N‐oxidized group are more affected than the opposing group. These differences in the conformational modes may contribute to rationalizing the distinctly different electronic properties of (4A) and (4B).     

The gas-phase decomposition of methylsilane. Part III. Kinetics

The homogeneous gas-phase decomposition kinetics of methylsilane and methylsilane-d₃ have been investigated by the comparative-rate-single-pulse shock-tube technique at total pressures of 4700 torr in the 1125–1250 K temperature range. Three primary processes occur: CH₃SiH₃ → CH₃SiH + H₂ (1), CH₃SiH₃ → CH₄ + SiH₂ (2), and CH₃SiH₃ → CH₂ = SiH₂ + H₂ (3). The high-pressure rate constants for the primary processes in CH₃SiH₃ obtained by RRKM calculations are log (k₁ + k₃) (s^?1) = 15.2 - 64,780 Cal/θ and log k₂ (s^?) = 14.50 - 67,600 → 2800 Cal/θ. For CH₃SiD₃ these same rate constants are log k₁ (s^?) = 14.99 - 64,700 cal/θ log k₂ (s^?) = 14.68 – 66,700 → 2000 cal/θ, and log k₃ (s^?) = 14.3 ? 64,700 cal/θ.     

Entanglement networks of 1,2-polybutadiene crosslinked in states of strain. VII. Stress-birefringence relations

Crosslinks are introduced by γ irradiation into 1,2-polybutadiene while strained in uniaxial extension near T_g with stretch ratio λ₀, thereby trapping a proportion of the entanglements originally present. The stress at any subsequent strain λ is accurately given by the sum σ_N + σ_x, where σ_N is the stress contributed by a trapped entanglement network with λ = 1 as reference and a Mooney–Rivlin stress-strain relation, and σ_x is that contributed by a crosslink network with λ = λ₀ as reference and neo-Hookean stress-strain relation. The birefringence is accurately given as δn = ?_Nσ_N + ?_xσ_x, where the ?'s are the respective stress-optical coefficients. From measurements at λ = λ₀ where σ_x = 0, ?_N can be determined separately. For polymer with 88% 1,2 microstructure, ?_N and ?_x are nearly equal and independent of irradiation dose, though strongly dependent on temperature. For polymer with (95–96)% 1,2, ?_N and ?_x are different (even opposite in sign) and dependent on dose. This behavior is associated with a side reaction of cyclization by the γ irradiation, which is inhibited by the 1,4 moiety in the polymer with lesser 1,2 content. It is responsible for residual birefringence in the state of ease (λ = λ_s) where σ_N = –σ_x and the stress is zero.     

Salt rejection by polymer membranes in reverse osmosis. II. Ionic polymers

The water permeability K₁ [which is related to water flux J₁ per unit membrane area by J₁ = K₁(Δp ? ΔII)/ΔX, where Δp is the pressure difference, ΔII is the osmotic pressure of feed solution, and ΔX is the membrane thickness] of homogeneous ionic polymer membranes in reverse osmosis and their salt rejection R_s [which is given by R_s ≡ 1 ? (C_2″/C_2′), where C_2′ is the concentration of the salt in feed solution, and C_2″ is the concentration of salt in effluent] were examined with cationic and anionic membranes of block and graft copolymers. For ionic membranes, R_s and K₁ are related by K₁ = A exp { ? BR_s}, where A and B are constants. This equation was found to be independent of the ion charge, the chemical nature of the polymer, and film morphology. The principle of salt rejection by ionic membranes was explained by the difference in the transport volumes (volume elements available for transport) for mobile co-ions and water. The electric repulsive force between a fixed ion and a mobile co-ion decreases the transport volume of the latter, thus creating a transport depletion of salt flux relative to water transport. This transport depletion is governed by the amount of water sorbed by a fixed ionic site, which also determines the water flux. Consequently, R_s and K₁ for ionically charged membranes are related as described above. This relation significantly differs from that found between R_s and K₁ for nonionic polymer membranes, where the size and the solubility of ions in the membrane are mainly responsible for the transport depletion. The decline of R_s with increasing K₁ is much less in ionic membranes than in nonionic ones; however, in the high R_s region, K₁ for both ionic and nonionic membranes become similar as the dominant mode of water transport changes from flow to diffusion.