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The thermal degradation of free fatty acids and animal fat in a moving bed of sodium carbonate and 5 wt% of water were carried out at 430 ± 20 °C at a pilot scale plant. During start-up the loading rates for a 60:40 mixture of oleic and stearic acids were 10 kg/h resulting in a 69 ± 5% of bio-crude. The acidity index was remarkably low within a range of 0.64–0.80 mg KOH/g during 3 weeks of operation. The loading rates for animal fat were increased from 10 to 40 kg/h corresponding to a weight hourly space velocity of 0.03–0.1 h−1 over a period of 6 months. Heat transfer into the reactor was the limiting criterion. The main product with a yield of 65 ± 5% was bio-crude showing an acidity index of 0.5–1.8 mg KOH/g. The mean value for kinematic viscosity at 40 °C was 1.78 mm2/s. The net calorific value of bio-crude was 41.6 MJ/kg. Coke deposits on sodium carbonate were determined to be 5 ± 1%. The gaseous products ranged from 25 wt% to 30 wt%. The presence of CO2, H2, CH4, C2H6, C2H4 and C3 to C5 hydrocarbons as major components was established by gas chromatography. The gases were directly fed into an on-site gas line and used for heating purposes. The distillation curve of bio-crude from animal fat showed hydrocarbon based bio-fuels in the boiling ranges of gasoline and diesel. Upon rectification 66% of bio-diesel and 21% of bio-gasoline were obtained. This corresponds to a total yield of 43% bio-diesel and 14% bio-gasoline from animal fat. The bio-diesel had favorable low-temperature properties (cold filter plugging point = −18 °C) with oxidation stability between that of mineral oil based diesel and fatty acid methyl ester fuels. The gasoline fraction lacked low-boiling hydrocarbons as indicated by a vapor pressure of 26 kPa instead of 60-90 kPa (DIN EN 228). Thus, water-cooled condensers need to be improved for a full-scale plant. The results are discussed in terms of German specifications for standard fuels.

Anaerobic low temperature conversion (LTC) converts organic residues such as animal meal or meat and bone meal (MBM) to bio-crude, a solid product, containing carbon and phosphorus, reaction water and non-condensable gases. The yield of bio-crude increases with the content of volatile solids. The efficiency of the conversion as well as the calorific value of the liquid fuel produced are favorably affected by the partial recycling of inorganic constituents, high amounts of volatile solids and a low percentage of heteroatoms present in the feeding material. Heating values are 32.3 MJ/kg for bio-crude from animal meal and 19.5 MJ/ kg for bio-crude from MBM. Both bio-crude and animal fat produced were effectively converted in a vertical reactor construction with a fixed bed of aluminosilicates of the zeolite family or acidic clays, respectively. Products are bio-fuels of varying chemical qualities. Depending on the reaction temperature and the catalyst type, aliphatic hydrocarbons (T=400°C, -97%) or alkylbenzenes (T = 550 °C) are the main products. The calorific values of these bio-fuels are in a range from 40.1 to 41.9 MJ/kg and the kinematic viscosities are between 0.9 and 2.29 mm 2 /s. The solid products of LTC from different biomass (sludge, animal meal, MBM) contain a significant amount of phosphorus. In the case of the solid product from MBM it was as high as 242 mg P 2 O 5 /g. Solubility in citric acid showed that in the case of MBM, 98.8 % of total phosphorus is potentially available to plants. Pot experiments demonstrated a similar plant growth as with other organic fertilizers.

To establish structure-activity relationships, derivatives of bis(O-alkyldithiocarbonato)platinum(II) complexes were analyzed. Eighteen bis(O-alkyldithiocarbonato) metal complexes were synthesized, and their cytotoxic activity on two human cancer cell lines was compared with the corresponding platinum bis(O-alkyldithiocarbonato) complexes and cisplatin. Complexes were synthesized with palladium, gold, nickel, copper, rhodium, and bismuth. Palladium and bismuth complexes were found to display significant cytotoxic activity. Palladium complexes were most active with up to 10-fold lower IC50 values as compared with the corresponding platinum complexes. The other complexes were only poorly active. Palladium, bismuth, and nickel complexes were more active at pH 6.8 than at pH 7.4. This difference in activity was most pronounced with palladium complexes. A pH of 6.8 and lower has been frequently found in solid tumors. Drugs with such pH dependent activity are supposed to have an improved therapeutic index as compared to drugs that are active irrespective of pH.

The preparation of the title compounds 9−11 was achieved by catalytic hydrogenation of 1,8-diazabicyclo[6.6.6]eicosa-4,11-diyne (13), 1,8-diazabicyclo[6.6.5]nonadeca-4,11-diyne (14), and 1,8-diazabicyclo[6.6.4]octadeca-4,11-diyne (15), respectively. As catalyst we used Pd(OH)2 on carbon. NMR studies on 9−11 revealed an in/in conformation at the bridgehead positions. Treatment of 9−11 with an excess of trifluoroacetic acid yielded, in a kinetically controlled reaction, mixtures of the out/out and in/out diprotonated species [9·2H]2+, [10·2H]2+ and [11·2H]2+. The thermodynamically controlled species, the corresponding in/in conformers, are formed at higher temperatures and longer reaction times. The experimental observations are supported by AM1 calculations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

To establish structure-activity relationships, derivatives of a recently described sulfur-containing antitumoral platinum complex, bis(O-ethyldithiocarbonato)platinum(II), named thioplatin, were analyzed. Twenty different bis(O-alkyldithiocarbonato)platinum(II) complexes were synthesized and tested for cytotoxic activity in a panel of six human tumor lines. Derivatives with up to 7-fold increased activity compared to thioplatin and up to 25-fold more activity than cisplatin were identified. Bis(O-alkyldithiocarbonato)platinum(II) complexes with short n-alkyl chains such as methyl, ethyl, propyl, and butyl were found to be superior to compounds with long n-alkyl chains such as hexyl, octyl, and decyl. Complexes derived from secondary xanthates displayed significantly higher activity than those derived from primary xanthates with the same number of C atoms. Like thioplatin, all tested platinum complexes were more active at pH 6.8 than at pH 7.4. A pH of 6.8 and lower has been frequently found in solid tumors because of the tendency of tumor cells to undergo anaerobic fermentation. Drugs with such pH-dependent antitumoral activity have an improved therapeutic index compared to drugs that are active irrespective of pH.

The refined (AUS concept, CCl4, external ref.) 1H NMR method provided association constants K and approximate complex shifts IK for stacking complexes of aromatic hydrocarbons D with A when A is 4-nitrobenzaldehyde (1) or is related to 1. D covers the benzene ring of A but torsionally vibrating substituents in A influence topology and K. In the absence of D, vibrations of A can be slowed by low temperatures making A signals go downfield in accord with an increased planarity of A. Vibration of CHO (a dipole) in complexes of 1 with benzene B or toluene T is made non-symmetric by interactions with the quadrupole of D. The large naphthalene (N) hinders vibrations thus enhancing the contact interface by a more planar 1 whose intramolecular deshielding of protons is increased providing small IK values. Aldehyde 1 forms complexes both with T and with its stacking dimer T2 since IK values for 1–T are significantly greater than for 1–B. Complexing with T2 is not found when the molecular dimensions of A allow a dipole–dipole interaction with T as in face-to-face complexes of 1-ethyltheobromine or of 1-chloro-2,4-dinitrobenzene (7). Different protons give slightly different values of K for 7–T and this points to an isomeric edge-on complex with both T and T2 where K for the two edge-on protons (shortest distance to D) is the sum of the binary K and the small K for the the ternary (7 + T2) complex. Compound 7 and 1,3,5-trimethylbenzene show some of the effect described for 1–N.

The glycyl radical (Gly-734) contained in the active form of pyruvate formate-lyase (PFL) of Escherichia coli is produced post-translationally by pyruvate formate-lyase-activating enzyme (PFL activase), employing adenosylmethionine (AdoMet) and dihydroflavodoxin as co-substrates. Previous 2H-labelings found incorporation of the pro-S hydrogen of Gly-734 into the 5'-deoxyadenosine co-product, indicating that a deoxyadenosyl radical intermediate, generated by reductive cleavage of AdoMet, serves as the actual H atom abstracting species in this system. We have now examined an octapeptide (Suc-Arg-Val-Pro-DeltaAla-Tyr-Ala-Val-Arg-NH2) that is analogous to the Gly-734 site of the PFL polypeptide but contains a dehydroalanyl residue (DeltaAla) in the glycyl position. Applied to the PFL activase reaction, this peptide becomes C-adenosylated at the olefinic beta carbon of DeltaAla. The modified peptide was isolated in micromol-quantities and characterized, after chymotryptic truncation, by MS and 2D NMR. PFL activase functions catalytically (kcat/= 1 min-1) in the peptide modification reaction, which occurs with stoichiometric consumption of AdoMet. The mechanism appears to involve addition of the nucleophilic deoxyadenosyl radical to the electrophilic CC double bond of DeltaAla, followed by quenching of the peptide backbone-centered adduct radical by the buffer medium. The trapping-property of the DeltaAla residue should be exploitable in investigating of how the Fe4S4 protein PFL activase generates the highly reactive deoxyadenosyl radical.

Following acetylation of an anthrocyan concentrate from black chokeberries (fruits of Aronia melanocarpa Elliot = Sorbus melanocarpa Heynh., Rosaceae), which is used as a natural food colouring agent, hexa-O-acetyl-sorbitol, penta-O-acetyl-glucopyranose (1), tetra-O-acetyl-β-D-glucopyranosyl benzoate (2), and hepta-O-acetyl-amygdalin (7) were detected by comparison with authentic samples. The structures of the hitherto unknown compounds 4-O-(tetra-O-acetyl-β-D-glucopyranosyl)pentan-2-one (3) and hepta-O-acetyl (2-pentanyl)-β-D-gentiobioside (8) were elucidated from their 1H,1H- and 13C,1H-COSY spectra. The structure of tetra-O-acetyl parasorboside was confirmed by crystal structure analysis.

From Bartramia stricta and B. pomiformis the new triluteolins epibartramiatriluteolin and strictatriluteolin along with the known bartramiatriluteolin were isolated. The structures and relative stereochemistry of these triluteolins have been elucidated spectroscopically.

A series of ten inverse calix[n]arenes (2–11) bearing four to thirteen benzene units were prepared by starting from 3,4,5-trimethoxybenzaldehyde followed by LC separation on silica gel. In 2–11 the substitution pattern is interchanged compared with the usual calixarenes. The conformational analysis was undertaken by variable temperature 1H-NMR spectroscopy and by MM2 calculations. Calix[4]arene 2 is a rigid molecule and shows the 1,3-alternate conformation which in addition was proven by X-ray analysis. At low temperatures the calix[5]arene 3 adopts the uudod conformation, where a methyl group of one benzene unit residues in the cavity of the macrocycle. At low temperature calix[6]arene 4 forms an 1:2 equilibrium between the 1,3,5-alternate (ududud; 4E) and the uududu (4B) conformation. Conformation 4B can be regarded as an intramolecular combination of a cone and an alternate arrangement of the benzene units. The calix[8]-arene shows the highest ΔG* value of the series and adopts an uuududdd conformation at low temperature. The inverse calixarenes 5 and 7–11 bearing seven and nine to thirteen aromatic units, respectively, are conformationally highly flexible systems even at low temperatures.

Leaves and stems of Abronia latifolia (Nyctaginaceae) are covered with a sticky material containing several flavonoid aglycones. In addition to some common flavones and flavonols, this exudate contains a novel C-methylated isoflavone (1), named abronisoflavone. This is the first report of the occurrence of an isoflavone in this family.

Anaphalis margaritacea, Gnaphalium chilense and G. microecephalum have been analyzed for flavonoid aglycones deposited externally on aerial parts. Anaphalis was found to produce, among others, several rare flavonoids, all of which are O-substituted in position 6 and mostly also in position 8. Both Gnaphalium species exhibit 3,5-dihydroxy-6,7,8-trim ethoxyflavone as the major exudate flavonoid.

3,14-Didehydro-10-hydroxyginkgolide1 (1) was prepared by reaction of 3,10-dihydroxyginkgolide (3) (ginkgolide “A”) by reaction with phosphoryl chloride in pyridine. Catalytic hydrogenation of 1 leads to 10-hydroxy-14-epiginkgolide (2a), which was epimerized with 4-(dimethylamino)pyridine (DMAP) in acetonitrile to give 10-hydroxyginkgolide (3a). 14-Epiginkgolide (2d) and ginkgolide (3d) were obtained from 2a and 3a via the 10-O-phenylthiocarbonyl derivatives 2c and 3c by means of a free-radical reduction with tri-n-butyltin hydride/α,α′-azobis(isobutyronitrile) (AIBN). By heating the 14-epiginkgolides 2a and 2b and the ginkgolides 3a and 3b in acetonitrile with DMAP an equilibrium on the side of the ginkgolides was established. The constitution and configuration of the compounds were proven by their 1H- and 13C-NMR spectra.

Radical-Type Cyclisation of Dienes, 111. – Radical-Type Cyclisation of (R)-( – )-Carvone – On the Influence of Charge- Transfer Interactions on the Optical Rotation Under the conditions of radical cyclisation, a 1:1 diastereomeric mixture of (1R,2S,5R,R)-(+)- (2a) and (1R.2S,5R,6S)-(+)-6-methoxy-2,6-dimethylbicyclo[3.2.1]octan-3-ones (2b) is obtained from (R)-(-)-carvone in 70% yield. the configuration fo 2a and 2b were confirmed by X-ray structure analyses of their hydrazones 2d and 2e. The regio- and stereoselectivity of the radical cyclisation of 1 to 2a and 2b are discussed. The high value of the specific rotation [-555] of 2d is traced back to charge-transfer interactions between the endo-standing methoxy group at C-6 as electron donor and the dinitrophenyl-hydrazone group as electron acceptor.

First evidence for the in vitro synthesis of a dimeric ellagitannin has been obtained with cell-free extracts from the weed Tellima grandiflora (fringe cups, Saxifragaceae). Partially purified enzyme preparations from leaves of this plant catalyzed the oxidation of 1,2,3,4,6-pentagalloyl-beta-D-glucose to the monomeric ellagitannin, tellimagrandin II, followed by oxidative coupling of two units of this intermediate to yield a dimeric derivative. Chemical degradation, MALDI-TOF mass spectrometry, 1H and 13C nuclear magnetic resonance, and CD spectroscopy were employed to identify this enzyme reaction product as cornusiin E which is characterized by a (S)-valoneoyl bridge between glucose-positions 2, 4' and 6'. This result was supported by comparison with data obtained for cornusiin E that had been isolated from leaves of intact T. grandiflora plants. No indication for the earlier proposed existence of rugosin D (an isomer with a 1,4',6'-bound valoneoyl unit) in T. grandiflora has been obtained in this investigation.

Pathways to complex gallotannins have been elucidated by enzyme studies, indicating that beta-glucogallin is required as principal acyl donor. Evidence for the in vitro oxidation of pentagalloylglucose, the pivotal metabolite in this sequence, to ellagitannins, is presented. Immunohistochemical studies with antibodies raised against pentagalloylglucose and the galloyltransferase catalyzing the formation of this ester revealed that leaf mesophyll cell walls were a typical site of origin and deposition of hydrolyzable tannins. Seasonal changes of these compounds were studied with extracts from cell walls and intracellular space of oak leaves.

First evidence of the in vitro oxidation of 1,2,3,4,6-pentagalloylglucose to the ellagitannins, tellimagrandin II and 1,4,6-tri-O-galloyl-2,3-O-hexahydroxydiphenoyl-β- D-glucose, has been obtained with a partially purified enzyme from leaves of Tellima grandiflora (fringe cups, Saxifragaceae).

Isolation and NMR-Spectroscopic Investigations of (−)-1-O-Benzyl-β-D-primveroside from Green Fruits of Prunus laurocerasus The TLC of the acetylated aqueous extracts of the green fruits of Prunus laurocerasus reveals two spots corresponding to pentaacetyl-glucopyranose and hexaacetyl-1-O-benzyl-β-D-primveroside (2), which can be quantitatively separated by flash chromatography. Saponification of 2 yields the free 1-O-benzyl-β-D-primveroside (1) which affords D-primverose (3) upon hydrogenolysis. The direct hydrogenolysis of 2 yields hexaacetyl-β-D-primverose (4). The structures of compounds 1–4 have been verified by NMR spectroscopy.

Aqueous acetone extracts of shoots of Eurasian watermilfoil (Myriophyllum spicatum) exhibit a strong inhibitory action against various coccoid and filamentous cyanobacteria and to a slightly less extent against chlorophytes and diatoms. Bioassay-directed fractionation led to the isolation of a hydrolysable polyphenol, tellimagrandin II, which turned out to be the main inhibitory substance. Myriophyllum spicatum contains large amounts of this compound (1.5% of dry wt). Part of the inhibitory activity is due to complexation and inactivation of algal extracellular enzymes (e.g. alkaline phosphatase) by hydrolysable polyphenols from M. spicatum.

First evidence of the in vitro oxidation of 1,2,3,4,6-pentagalloylglucose to the ellagitannins, tellimagrandin II and 1,4,6-tri-O-galloyl-2,3-O-hexahydroxydiphenoyl-β- D-glucose, has been obtained with a partially purified enzyme from leaves of Tellima grandiflora (fringe cups, Saxifragaceae).

Natural abundance 15N NMR spectra of various aliphatic lactams and of the corresponding polyamides were measured in trifluoroacetic acid. Cis and trans amide bonds were found to have nearly identical shifts and identical 1JNH coupling constants. Increasing chain length of the monomeric units and increasing ring size result in a downfield shift of the 15N signals. The 13C NMR spectra display, on the other hand, remarkable shift differences for lactams and Nylons. The polyamides show a monotonic downfield shift of the carbonyl signal with increasing chain length of the monomeric unit in contrast to the lactams. The 13C NMR spectra of the lactams were measured in various solvents; they show a downfield shift of the carbonyl signals with increasing acidity of the solvent. Protic solvents also favor strongly the cis-form of 1-aza-2-cyclononanone over the trans-form.

Durch umfangreiche chromatographische Trennungen ist es gelungen, aus Valoneagerbstoff1 eine neue Verbindung C41, H30O28 zu isolieren, die als Isomeres der Valolaginsaure2 Isovalolaginsaure (1) genannt wird. 1 gibt bei der saurer Hydrolyse Ellagsaure und Isovalolinsaure (2, C27H24O20). Unter verscharften Hydrolysebedingungen liefert 2 Trillosauretrilacton I (3), das als Hexamethylderivat 3a charakterisiert wurde. Mit Diazomethan entstehen aus 1 eine Tetradeca-O-methylverbindung 1a und als Nebenprodukt eine Pentadeca-O-methylverbindung 1c. Von diesen ergibt 1a das Diacetylderivat 1b und 1c das Monoacetylderivat 1d. Die Einwirkung von Methanol/Natriummethylat auf 1a liefert (−)-Hexamethoxydiphensauredimethylester. Danach und nach eingehenden 1H-NMR-Untersuchungen besitzt Isovalolaginsaure die Struktur 1. Sie unterscheidet sich damit nur in der Konfiguration an C-l von Valolaginsaure. On Valonia Tannins, VI1). — Isovalolaginic Acid A single tannin of the composition C41, H30 O28. isomeric with valolaginic acid2) and named isovalolaginic acid (1). was isolated from valonia tanninsa by an extended series of chromato- graphic separations. Acidic hydrolysis of 1 yielded ellagic acid and isovalolinic acid (2, C27H24O20). On drastic hydrolysis 2 yielded the trilactone of trilloic acid (3). which was characterised as the hexa-O-methyl derivative1) 3a. — On methylation with diazomethane 1 produced LL tetradeca-O-methyl compound l a and a small quantity of a pentadeca-O-methyl derivative Ic. Compound 1a gave the diacetyl derivative 1b and 1c the monoacetyl derivative 1d. Compound 1a is cleaved by methoxide ion (in methanol) and yields dimethyl (—)-hexa- methoxydiphenoate. — These statements and additional intensive 1H-NMR investigations show isovalolaginic acid to have structure 1 and differ from valolaginic acid only in the configuration at c-I.

Die beiden C30H24O12-Procyanidine A1 und A2 sind Strukturisomere, die sich in der CC– Verknupfung des Procyanidinteils mit dem ()-Epicatechinteil unterscheiden. Mit Hilfe der 1H- und 13C-NMR-Spektroskopie wird gezeigt, das beim Procyanidin A1 eine C-4—C-8′- Verknupfung entsprechend Struktur 1 und beim Procyanidin A2 eine C-4—C-6′Bindung entsprechend Struktur 3 vorliegt. Isomerism of the C30H24O12-procyanidins, a 1H- and 13H13C-NMR Spectroscopic Investigation The two C30H24O12-procyanidins A1 and A2 are structural isomers differing in the CC bond between the procyanidin and the ()-epicatechin moietis. It is shown by 1H and 13C-NMR spectroscopy that in the procyanidin A1 the two parts of the molecule are connected by a C-4—C-8′ bond as in structure 1 and in the procyanidin A2 by a C-4—C-6′ bond as in structure 3.

Die aus Valoneagerbstoff, dem komplexen Gerbstoffgemisch aus den Fruchtbechern griechischer und vorderasiatischer Eichen (vor allem Quercus valonea, aegilops und macrolepis),durch umfangreiche chromatographische Trennungen erhaltliche Valolaginsaure (1) der Zusammensetzung C41H30028 besitzt - wie am den Derivaten l a -l d hervorgeht - 2 freie Carboxygruppen und 14 phenolische sowie 2 aliphatische Hydroxygruppen. 1 liefert bei saurer Hydrolyse Valolinsaure (2) (Derivate 2a-2c) und Ellagsaure. Letztere ist in 1 als (-)-4,5,6,4′,5′,6′-Hexahydroxydiphensaure gebunden, was durch das Methanolyseprodukt (-)-4,5,6,4′,5′,6′-Hexamethoxydiphensaure-dimethylester aus 1 c bewiesen wird. Auf Grund dieser Befunde und weiterer eingehender 1H-NMR-Untersuchungen wird fur Valolaginsaure Struktur 1 und fur Valolinsaure Struktur 2 vorgeschlagen. On Valonia Tannins, IV.- Valolaginic Acid A single tannin of the composition C41H30028, named valolaginic acid (l), was isolated from a mixture of Valonia tannins (obtained from the calyx of Quercus valonea, aegilops, and macrolepis) by an extended series of chromatographic separations. 1 has 2 free carboxyl, 14 phenolic, and 2 aliphatic hydroxyl groups, as seen for derivatives 1 a-ld. Acidic hydrolysis of 1 yielded valolinic acid (2) (derivatives 2a-2c) and ellagic acid. In 1 the latter is esterified in the form of (-)-4,5,6,4′,5′,6′-hexahydroxydiphenic acid, as is confirmed by the methanolysis product of 1, i. e. dimethyl (-)-4,5,6,4′,5′,6′-hexamethoxydiphenoate. On the basis of these findings and further detailed IH-NMR investigations structure 1 was assigned to valolaginic acid and structure 2 to valolinic acid.

Summary The Californian silver fern, Pityrogramma pallida , produces a copious farinose exudate, which mainly consists of C-methylflavanones. Six minor constituents could now be isolated and identified by spectral methods. Four flavanones are distinguished by methoxyl groups at C-5; two of them are derivatives of pinocembrin, two are in addition C-methylated at C-6. Two chalcones have corresponding substitution patterns. All flavonoids produced by this fern bear an unsubstituted B-ring. Most of them are rare, two are novel natural products.

Alanine-N-carboxylic acid anhydride (Ala-NCA) was copolymerized with glycine-NCA, phenylalanine-NCA, valine-NCA, leucine-NCA, and sarcosine-NCA in various solvents and with various catalysts; 22,6 MHz 13C NMR spectra and 90 MHz 1H NMR spectra of the resulting copolypeptides were measured in trifluoroacetic acid and from the signal intensities the rate of incorporation was estimated. The copolypeptides poly(Ala/Gly) and poly(Ala/Phe) contained both monomeric units in an almost equal concentration, while the low reactivity of Val-NCA and Leu-NCA resulted in a lower concentration of these residues compared with Ala in poly(Ala/Val) and poly(Ala/Leu). The 13C NMR spectra of poly(Ala/Gly) exhibit four CO-signals which could be assigned by comparison with the corresponding homopolypeptides and with the sequence polypeptides (Ala-Ala-Gly-Gly)n, and (Ala-Gly-Gly)n. From the intensities of these CO-signals the average length of the homogeneous blocks was calculated. Both block lengths and rate of incorporation proved to be almost independent of solvent, catalyst, and reaction temperature. Poly(Ala/Phe) and poly(Ala/Sar) show also four CO-signals, but poly(Ala/Val) only two and poly(Ala/Leu) one. The number and shape of the CO-signals allow one to decide whether random copolypeptides were obtained or not.

Nach 1H- und 13C-NMR-spektroskopischen Befunden liegt D-Hamamelose (1; 2-C-Hydroxymethyl-D-ribose) in Losung als Gemisch der beiden Furanosen und Pyranosen vor. Die Lage des Gleichgewichts wurde in D2O und [D6]DMSO bestimmt. Die beiden Hamamelopyranosen bevorzugen die 1C4-Konformation. 13C-NMR Spectroscopy of Natural Products, VII. - Composition and Conformation of Hamamelose in Solution According to 13C and 1H-NMR spectra, D-hamamelose (1; 2-C-hydroxymethyl-D-ribose) exists in solution as a mixture of the two furanoses and the two pyranoses. The equilibrium composition was determined in D2O and [D6]DMSO. The 1H-NMR data for both the pyranoses are consistent with preference for the 1C4-conformation.

Cell-free extracts from oak (Quercus robur) leaves catalyze the transfer of the galloyl-moiety of β-glucogallin (1-O-galloyl-β-D-glucopyranose) specifically to the 6-position of the same compound, yielding 1,6-di-O-galloyl-β-D-glucopyranose, an intermediate of gallotannin biosynthesis, β- Glucogallin thus functions as both donor and acceptor molecule in this reaction. The partial purification and some general properties of this new acyltransferase are reported.

Isoceroptene, a polyphenol isolated in trace amount from the farinose frond exudate of Pityro­gramma triangularis, is shown by spectroscopic means to possess the structure of one of the two possible “flavanone” isomers formed by ring closure of the “chalcone” ceroptene. The tautomeric structures best representing ceroptene and a related dihydrochalcone from Myrica gale are defined by 1H-NMR spectroscopy.

Die 13C-Chemische Verschiebung des Carbonylkohlenstoffs in Polyamiden, ω-Aminocarbonsauren und N-substituierten Saureamiden wurde in Abhangigkeit von der Saurekonzentration (D2SO4,CF3COOD, D2O) untersucht. Polyamide ahneln dabei in ihrem spektroskopischen Verhalten weit mehr den ω-Aminocarbonsauren als den analogen monomeren Saureamiden. Die Gesetzmasigkeiten der auftretenden Chemischen Verschiebungen und die sich hieraus ergebenden Folgerungen fur die Sequenzanalyse von Polyamiden werden diskutiert. The 13C-chemical shift for the carbonyl carbon in polyamides, ω-aminocarboxylic acids, and N-substituted carboxylic amides is studied at different acid concentrations (D2SO4, CF3COOD, D2O). It is found, that the spectroscopic behaviour of polyamides resembles more to ω-aminoacids than to monomeric amides. The rule of the observed chemical shift and the resulting consequences for the sequence determination in polyamides are discussed.

The white farinose exudate on the fronds of Cheilanthes argentea contains a series of flavanones as minor constituents. These were identified by spectroscopic methods as: 5,4′-diOH,6,7-diOMe flavanone and its 4′-OMe derivative, 5,4′-diOH,7,8-diOMe flavanone and its 4′-OMe derivative, 5,6-diOH,7,8,4′-triOMe flavanone, 5,4′-diOH, 6,7,8-triOMe flavanone and its 4′-OMe derivative. The farina of Notholaena limitanea var. mexicana contains eriodictyol-7,4′-di-methyl ether and eriodictyol-7,3′, 4′-trimethyl ether as minor components. Both compounds were also identified in the exudate of N. fendleri, together with naringenin-7-OMe and naringenin-4′-OMe. In N. lemmonii var. lemmonii trace amounts of 5-OH,7,3′,4′,5′-tetra-OMe flavanone were detected. Nine of these substances are novel natural flavanones.