Fenugreekine,a new steroidal sapogenin-peptide ester of Trigonella foenum-graecum

A new C₂₇-steroidal sapogenin-peptide ester, fenugreekine, has been isolated from seeds of Trigonella foenum-graecum. On acid hydrolysis, it afforded diosgenin, yamogenin, (25R)-spirosta-3,5-diene, a mixture of three isomeric (2S,3R,4R-, 2S,3R,4S-, 2S,3S,4R-)-4-hydroxyisoleucine lactones, 4′-hydroxyisoleucyl-4-hydroxyisoleucine lactone, and a C₁₄-dipeptide which was partially characterized. On the basis of this chemical transformation and spectral (UV, IR, PMR, MS) evidence of fenugreekine and its transformation products, the steroidal sapogenin-peptide ester is assigned structure (1). The two dipeptides also have not been encountered before in nature or prepared synthetically. The compound shows a number of interesting pharmacological and virological activities.     

Synthesis of new symmetrical bis-steroidal pyrazine analogues from diosgenin

New symmetrical bis-steroidal pyrazine dimers that are cephalostatins/ritterazines analogues have been prepared easily from a cheap, readily available natural steroid (diosgenin). These dimers were obtained by classical, condensation of α-amino ketones in order to construct the pyrazine rings. The three dimers differ in the functionalized diosgenin: (25R)-5α,6β-dihydroxy-5α-spirosta-3-one, (25R)-4,5α-epoxy-5β-spirosta-3,6-dione and (25R)-5α-hydroxy-5α-spirosta-3,6-dione respectively.     

The resolution of 25α- and 25β-spirosta-3,5-dienes from sapogenin yielding plants

The separation of the artefacts, 25α- and 25β-spirosta-3,5-dienes, is described and their individual characters are recorded. Following acid hydrolysis of plant material the ratios of diene to sapogenin and of 25α- to 25β-diene varied with different species and morphological parts. The 25α-diene commonly predominated as did diosgenin over yamogenin. Diene production is reduced when, before undergoing acid hydrolysis, the plant material is incubated with water for increased sapogenin yield. The label from acetate-2-¹⁴C was found predominantly in the 25α-diene from such an incubation-acid hydrolysis experiment.     

Some variations in the composition of suberin from the cork layers of higher plants

The monomeric composition of the suberins from 16 species of higher plants was determined by chromatographic methods following depolymerization of the isolated extractive-free cork layers with sodium methoxide-methanol. 1-Alkanols (mainly C₁₈C₂₈), alkanoic (mainly C₁₆C₃₀), α,ω-alkanedioic (mainly C₁₆C24), ω-hydroxyalkanoic (mainly C₁₆C₂₁), dihydroxyhexadecanoic (mainly 10,16-dihydroxy- and 16-dihydroxyhexadecanoic), monohydroxyepoxyalkanoic (9,10-epoxy-18-hydroxyoctadecanoic), trihydroxyalkanoic (9,10, 18-trihydroxyoctadecanoic), epoxyalkanedioic (9,10-epoxyoctadecane-1,18-dioic) and dihydroxyalkanedioic (9,10-dihydroxyoctadecane-1 18-dioic) acids were detected in all species. The suberins differed from one another mainly in the relative proportions of these monomer classes and in the homologue content of their 1-alkanol, alkanoic, α,ω-alkanedioic and ω-hydroxyalkanoic acid fractions. C₁₈ epoxy and vic-diol monomers were major components (32–59%) of half of the suberins examined (Quercus robur, Q. ilex, Q. suber, Fagus sylvatica, Castanea sativa, Betula pendula, Acer griseum, Fraxinus excelsior) where as ω-hydroxyalkanoic and α,ω-alkanedioic acids predominated in those that contained smaller quantities of such polar C₁₈ monomers (Acer pseudoplatanus, Ribes nigrum, Euonymus alatus, Populus tremula, Solanum tuberosum, Sambucus nigra, Laburnum anagyroides, Cupressus leylandii). All species, however, contained substantial amounts (14–55 %) of ω-hydroxyalkanoic acids, the most common homologues being 18:1 (9) and 22: 0. The dominant α,ω-alkanedioic acid homologues were 16: 0 and 18: 1 (9) whereas 22: 0, 24: 0 and 26: 0, and 20: 0, 22: 0 and 24: 0 were usually the principal homologues in the 1-alkanol and alkanoic acid fractions, respectively. The most diagnostic feature of the suberins examined was the presence of monomers greater than C₁₈ in chain length; most of the C₁₆ and C₁₈ monomers identified in the suberins also occur in plant cutins emphasizing the close chemical similarity between the two anatomical groups of lipid biopolymer.     

Epicuticular waxes from Agropyron dasystachyum,agropyron riparium and Agropyron elongatum

Epicuticular waxes from whole plants of Agropyron dasystachyum var. psammophylum, A. riparium and A. elongatum contain hydrocarbons (5–8 %), long chain esters (12–15%) and free acids (2–5%). The major esters are C₃₄C₅₆ esters derived from C₁₆C₃₀ acids and alcohols (1-hexacosanol is the major alcohol) but C₃₁, C₃₃ and C₃₅ esters (3–11%) are also present. The latter esters are C₁₈ and C₂₀ acid esters of C₁₃ and C₁₅ 2-alkanols. A. dasystachyum wax contains 2% free alcohols, that of A. riparium contains 17% and that of A. elongatum 11% (1-hexacosanol is the major alcohol in each). Diesters (2%), C₈C₁₂ diols esterified by (E)-2-alkenoic acids, are present in A. riparium wax. Hentriacontane-14,16-dione is present: 29% in A. dasystachyum wax and 32% in A. riparium wax, but only 5% in A. elongatum wax. 25-Oxohentriacontane-14,16-dione forms 14% of A. dasystachyum wax and 27% of A. elongatum wax but the oxo β-diketones of A. riparium wax (5%) consist of both 10-oxo- and 25-oxohentriacontane-14,16-diones in the ratio 4:1. Hydroxy β-diketones of the waxes are 25- and 26-hydroxyhentriacontane-14,16-diones; in A. dasystachyum (20%) the ratio is 3:1, in A. elongatum (20%) the ratio is 9:1 but in A. riparium (5%) it is ca 1:2. The configuration of the hydroxyl group in the 26-hydroxy β-diketone is opposite to that in the 25-hydroxy derivative. The unusual composition of the oxygenated β-diketones of A. riparium confirms that this species should be regarded as separate from A. dasystachyum. Wax from A. elongatum also contains 4-hydroxy-25-oxohentriacontane-14,16-dione (4%) and an unusual oxo-β-ketol, 18-hydroxy-7,16-hentriacontanedione (2%), both these components are probably derived biosynthetically from the 25-oxo β-diketone which is the major component of this wax. Syntheses of racemic 18-hydroxy-7,16-hentriacontanedione and of a model β-ketol, 12-hydroxy-10-pentacosanone, are described.     

Alkadiene- and botryococcene-producing races of wild strains of Botryococcus braunii

Samples of the green colonial alga Botryococcus braunii, collected from various localities, were grown in the laboratory and examined for their hydrocarbon content and morphology. Although few differences appeared between the ultrastructures of the samples, the nature of their hydrocarbons, which remains unchanged at any stage of growth, allows the distinction of two physiological races viz algae producing odd-numbered unbranched alkadienes and trienes (C₂₅C₃₁) (the A race) and those producing polymethylated triterpenes C_nH_2n-₁₀ (C₃₀C₃₇), the botryococcenes (the B race). In laboratory culture, the hydrocarbon content of these new strains is very high, from 30 to 60% of the dry biomass. For the two races the greatest hydrocarbon productivity takes place during the active growth phase. The important variability observed in botryococcene distribution could originate both from genetic and environmental factors.     

Novel effects of diosgenin on skin aging

Extracts of Dioscorea coomposita or Dioscorea villosa are consumed as supplemental health foods at the time of climacteric. The extracts contain large amounts of the plant steroid, diosgenin. Here, we studied the safety and efficacy of diosgenin against skin aging at the time of climacteric. In vitro, diosgenin enhanced DNA synthesis in a human 3D skin equivalent model, and increased bromodeoxyuridine uptake and intracellular cAMP level in adult human keratinocytes. The increase of bromodeoxyuridine uptake by diosgenin was blocked by an adenylate cyclase inhibitor, but not by antisense oligonucleotides against estrogen receptor α, estrogen receptor β or an orphan G-protein-coupled receptor, GPR30, indicating the involvement of cAMP but not estrogen receptor α, estrogen receptor β or GPR30. In vivo, administration of diosgenin improved the epidermal thickness in the ovariectomized mice, a climacteric model, without altering the degree of fat accumulation. In order to examine the safety of diosgenin, diosgenin and 17β-estradiol were administered to breast cancer-burdened mice. The results revealed that while 17β-estradiol accelerated the tumor growth, diosgenin did not show this effect. Our finding, a restoration of keratinocyte proliferation in aged skin, suggests that diosgenin may have potential as a safe health food for climacteric.     

Participation of C6C1 unit in the biosynthesis of ephedrine in Ephedra

Feeding of benzoic acid-[7-¹⁴C], benzaldehyde-[7-¹⁴C] and cinnamic acid-[3-¹⁴C] to Ephedra distachya resulted in efficient incorporations of ¹⁴C into the α-carbon atom of the side chain of l-ephedrine. Thus ephedrine was shown to be biosynthesized by the condensation of a C₆C₁ portion which is derived from phenylalanine via cinnamate and an unidentified C₂-N fragment.     

Three-liquid-phase extraction of diosgenin and steroidal saponins from fermentation of Dioscorea zingibernsis C. H. Wright

Diosgenin is an important starting material in the steroidal hormone industry. The yield of diosgenin obtained from the fermentation of Dioscorea zingibernsis C. H. Wright (DZW) by Trichoderma harzianum is higher than that typically obtained from acid hydrolysis. In this paper, the extraction of steroids in the culture broth was studied. A novel three-liquid-phase system (TLPS) consisted of petroleum ether, ethanol, ammonium sulphate and water was used to separate diosgenin and steroidal saponins in the culture broth. The partition behaviors of various steroidal saponins, diosgenin and glucose were investigated. From this, an optimized TLPS was obtained, which composed of 30% ethanol (w/w), 17% (NH₄)₂SO₄ (w/w) and 40% (w/w) petroleum ether. In the optimized TLPS, almost all of the diosgenin was extracted into the top phase giving a recovery of 97.24%, whereas the steroidal saponins were mainly extracted into the middle phase, with recoveries of zingibernsis newsaponin, deltonin and diosgenin-diglucoside reaching almost 100%. The recoveries of trillin and diosgenin-triglucoside were 96.03% and 98.82%, respectively. Glucose tended to remain in the bottom phase, giving a recovery of 72.01%. The three-liquid-phase extraction (TLPE) successfully resulted in the simultaneous separation of diosgenin, untransformed steroidal saponins and glucose.     

Variation of stilbene glucosides in bark extracts obtained from roots and stumps of Norway spruce (Picea abies [L.] Karst.)

Acetone-soluble compounds found in different root zones and stumps of Norway spruce (Picea abies [L.] Karst), which were grown on either peatland or a mineral soil site, were studied. Samples from stumps and roots of different sizes and ages were collected a day after the trees were felled. The wood and bark of stumps and three zones of the roots were separated and extracted with acetone in an ultrasonic bath. Extracts were silylated and analysed by gas chromatography–mass spectrometry. The stilbene glucosides astringin and isorhapontin were major compounds in the spruce bark samples. The resveratrol glucoside piceid and the flavonoid catechin were also extracted from spruce bark. We also found the lignan hydroxymatairesinol in some wood extracts. Total concentrations of stilbene glucosides in bark of stumps and different root zones varied between 0.53 and 8.29 % (w/w, dry weight) with isorhapontin being the major compound. Isorhapontin concentrations were highest in the spruce samples grown on mineral soil. The bark of the roots close to the stem is a rich source of stilbenes for commercial utilisation.     

Molecular packing of high density lipoproteins: a postulated functional role.

The bovine α_s2-, α_s3-, α_s4- and α_s6-caseins [1] were isolated. The 4 proteins had the same amino-acid composition and C-terminal sequence, but different phosphorus contents. From a mixture of these proteins (designated as ‘α_s2-complex’) and from α_s3-casein a single and identical N-terminal sequence was obtained by Edman degradation. It seems therefore that the 4 proteins have the same peptide chain and only differ in their phosphorus content. For this reason we propose to modify the nomenclature of Annan and Manson [1] and to use in future the single term α_s2 to designate the caseins which have been previously called α_s2, α_s3, α_s4 and α_s6 by these authors. The study of the primary structure of the peptide chain, which has confirmed these results, was undertaken on the S-carboxymethylated α_s2-complex. From a cyanogen bromide digest and from a tryptic hydrolyzate of the α_s2-complex, 5 and 25 peptides were obtained respectively, both sets of peptides accounting for the whole peptide chain. Examination of the tryptic peptides containing methionine combined with the N- and C-terminal sequences of the α_s2-complex and some CNBr peptides, gave the order of the CNBr peptides, H.CN4CN2CN5CN1CN3.OH, which contain 4, 22, 115, 49 and 17 residues respectively. A partial sequence accounting for half of the peptide chain of the α_s2-complex is given. This peptide chain is likely composed of 207 amino-acid residues     

The synthesis of technetium(V) complexes containing sterically bulky thiolate ligands. The molecular structure of tetrabutylammonium oxotetrakis(2,4,6-trimethylbenzenethiolato)technetate(V)

The reactions between [TcOCl₄]⁻ and the sterically bulky thiols ArSH (Ar = 2,4,6-Me₃C₆H₂, 2,4,6- Prⁱ₃C₆H₂ and 2,6-Ph₂C₆H₃) in methanol afford complexes of formula [TcO(SAr)₄]⁻ which may be isolated as salts with bulky organic cations. The molecular structure of [Buⁿ₄N][TcO(2,4,6-Me₃C₆H₂S)₄] was determined by X-ray diffraction methods. The Tc(V) centre was found to adopt the expected square pyramidal geometry in which an oxo group occupies the apical site and the four thiolate sulphurs the basal sites. The TcO distance is 1.659(11) Å and the average TcS distance 2.38(2) Å. The average cis STcS, trans STcS and OTcS angles are respectively 82.7(6)°, 138.4(3)° and 110.8(4)°.     

Essential oil of Psiadia salviifolia

Utilizing GLC, IR, combined GC-MS, the following constituents were identified in the essential oil of Psiadia salviifolia; β-pinene, limonene, γ-terpinene, p-cymene, α-copaene, linalool, β-bourbonene, α-himachalene, γ-cadinene, δ-cadinene, -γ-elemene, and a hydroxy derivative of calamenene. A new monoterpene hydrocarbon was also isolated which from MS and IR evidence was named as 7-methyl-3-methylene-octa-1,4-diene.     

Production of alkanes (C7–C29) from different part of poplar tree via direct deoxy-liquefaction

Poplar leaves, poplar bark and poplar wood were deoxy-liquefied directly in an air-proof stainless steel reactor at different temperatures. The oils from leaves at 350 °C, from bark at 400 °C and from wood at 450 °C, at which the liquid product yields were the maximum, were analyzed by GC–MS. The oils obtained from three parts of poplar tree were quite different from each other in the relative contents of their compositions. The oil from leaves was rich in hydrocarbons (alkanes: C₇–C₂₉; aromatics) and poor in phenolics, while oil from wood was rich in phenolics and poor in hydrocarbons. The oil from bark was moderate. Relative contents of hydrocarbons in the leaves oil were as high as 60.01% but decreased to 29.71% in bark oil and 11.43% in wood oil. GC analysis of gases and FT-IR, GC–MS and elemental analysis of oils were performed in this study.     

Triterpenes from Maytenus horrida

The new triterpene 1β,3β,11α-trihydroxyolean-12-ene and the already known compounds, lupeol, germanicol, 3β-hydroxy-glutin-5-ene, β-amyrin, 3β-hydroxyolean-9(11),12-diene, 3-oxo-olean-9(11),12-diene, 3β,11α-dihydroxyolean-18-ene,3β,11α-dihydroxyolean-12-ene, 3β,29-dihydroxy-glutin-5-ene and dulcitol, were isolated from the root bark of Maytenus horrida.     

Solution behaviour and relative stability of the complexes [MCl2(RNCHCHNR)] and [MCl2(py-2-CHNR)] (M=Pd,Pt;R=C6H4OMe-p)

Even though the α-diimino complexes [MCl₂(RNCHCHNR)] and [MCl₂(py-2-CHNR)] (M=Pd, Pt;R=C₆H₄OMe-p) are poorly soluble in chlorinated solvents, such as chloroform and 1,2-dichloroethane, or in acetonitrile, the electronic and ¹H NMR spectra indicate that these compounds are generally present as undissociate monomers with σ, σ′-N,N′ chelate N-ligands in dilute solutions. Only for [PdCl₂(RNCHCHNR)], some dissociation of the α-diimine occurs in acetonitrile. In dimethylsulfoxide, where the solubility is much higher, no dissociation is observed for the pyridine-2-carbaldimine complexes [MCl₂(py-2-CHNR)], whereas the 1,2-bis(imino) ethane derivatives [MCl₂(RNCHCHNR)] are extensively dissociated through a step-wise process involving intermediates with a σ-N monodentate α-diimino group. As is shown by the course of substitution reactions with 2,2′-bipyridine, the higher stability of [MCl₂(py-2-CHNR)] in dimethylsulfoxide is mainly due to thermodynamic factors (ground state stabilization for the presence of stronger MN bonds) rather than by kinetic factors (higher activation energy for steric strain in the activation states or transients).     

Synthesis,characterization, and molecular structure of the quadruply bonded ditungsten(ll) complex,W2Cl4(dppm)2

The reaction of W₂Cl₄[P(n-Bu)₃]₄ with bis(diphenylphosphino)methane (dppm) affords the highly air-sensitive material, W₂Cl₄(dppm)₂, which has been characterized by IR and visible spectroscopy, and by X-ray crystallography. The compound crystallizes in the centrosymmetric space group C2/c with the following parameters: a = 17.298(3); b = 17.011- (2); c = 18.413(2) Å; β = 98.93(2); V = 5352(2) ų; Z = 4. The molecule is positioned about a C₂ axis which allows for a net torsion angle of 17.25° down the WW vector. This does not seem to significantly effect the WW bond distance (2.269(1) Å) relative to other quadruply bonded ditungsten species.     

Crystal structure of [chloro(diethyldithiocarbamato)butyl phenyl]tin(IV)

The crystal structure of the title compound, SnCl(C₆H₅)(C₄H₉)[S₂CN(C₂H₅)₂], was determined and refined to an R factor of 3.2% for 4876 reflections. The molecule contains five-coordinate tin in a distorted trigonal bipyramidal arrangement with the tin atom lying 0.20 Å below the equatorial plane formed by one of the sulphur atoms, S(1), and the donor carbons of the butyl and phenyl groups. The chlorine and the other sulphur atom, S(2), occupy axial sites, making a S(2)SnCl angle of 156.85(1)°. The SnS(2) bond is markedly elongated (2.764(1) Å) compared to the SnCl bond (2.449(1) Å) and the SnS(1) bond (2.454(1) Å). The structure resembles those of analogues such as (C₆H₅)₂Sn(glygly) in having both hydrocarbon ligands located in the equatorial plane. Crystal data: space group P$\text{1}$: a = 8.291(2) Å, b = 14.726(3) Å, c = 9.509(2) Å, α = 96.24(2)°, β = 107.02(3)°, γ = 116.70(2)°, Z = 2, R = 3.2% for 4876 independent reflections.     

Resonance Raman spectroscopy of chemically modified retinals: Assigning the carbon-methyl vibrations in the resonance Raman spectrum of rhodopsin

To assign the observed vibrationsl modes in the resonance Raman spectrum of the retinylidene chromophore of rhodopsin, we have studied chemically modified retinals. The series of analogs investigated are the n-butyl retinals substituted at C₉ and C₁₃. The results obtained for the 11-cis isomer have clearly assigned the CCH₃ vibrational frequencies observed in the spectrum of the retinylidene chromophore. The data show that the C₍₉₎CH₃ stretching vibration can be assigned to the vibrational mode observed in the 1017 cm^?1 region, and the vibration detected at 997 cm^?1 can be assigned to the C₍₁₃CH₃ vibration. The C₍₅₎CH₃ stretching mode does not contribute to the vibrations observed in this region. The splitting in the C_(n)CH₃ (n = 9, 13) vibration is characteristic of the 11-cis conformation. The results on the modified retinals do not support the hypothesis that the splitting arises from equilibrium mixtures of 11-cis, 12-s-cis and 11-cis, 12-s-trans in solution. Thus, this splitting cannot be used to determine whether the chromophore in rhodopsin is in a 12-s-cis or 12-s-trans conformation. However, our results demonstrate that there are other vibrational modes in the spectra which are sensitive to this conformational equilibrium and we use the presence of a strong ~ 1271 cm^?1 mode in bovine and squid rhodopsin spectra as an indication that the chromophore in these pigments is 11-cis, 12-s-trans.     

Epicuticular wax of Agropyron intermedium

Wax on leaves of Agropyron intermedium contains hydrocarbons (11%, C₂₇–C₃₃), esters (11%, C₃₂–C₆₀), free alcohols (180%, C₂₆) 25-oxohentriacontane-14,16-dione (17%), 10-oxohentriacontane-14,16-dione (5y%), 25-hydroxyhentriacontane-14,16-dione (12%) and 26-hydroxyhentriacontane-14,16-dione (2%). Wax on spikes contains additional components, C₂₅–C₃₃cis 9-alkenes (32% of hydrocarbons), and more β-diketones, 25-hydroxy (17%) and 26-hydroxy (3%) hentriacontane-14,16-diones, 10,25-dioxohentriacontane-14,16-dione (1%) and 4-hydroxy-25-oxo-(2%), 25-hydroxy-10-oxo-(1.3%) and 26-hydroxy-10-oxo-(0.7%) hentriacontane-14,16-diones; free alcohols were very minor components (1%, C₂₄–C₃₂).