Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.     

Pentaketide metabolites of mutants and the biosynthesis of melanin inVerticillium tricorpus

From mutants of the fungusVerticillium tricorpus Isaac., having various genetic blocks in the biosynthesis of melanin, we have isolated and identified scytalone, flaviolin, 3,3′-biflavinolin, 2-hydroxyjuglone, vermelone, and 1,8-dihydroxynaphthalene, which, in combination with the results of complementation analysis, has enabled the main stages of the biosynthesis of melanin inV. tricorpus to be established. The results on the inhibition of the biosynthesis of melanin by tricyclazole in natural isolates ofV. tricorpus indicates that the initital stages of the biosynthesis of melanin inV. tricorpus up to the formation of 1,3,8-trihydroxynaphthalene are identical with those ofVerticillium dahliae.     

Lipopolysaccharides of marine blue-green algae

The lipopolysaccharides (LPSs) have been isolated from two blue-green algae,Oscillatoria hilderbrandtii andNostoc sp. by the method of phenol-water extraction. The LPSs contain polysaccharide and lipid components. The polysaccharide fraction fromO. hildebrandtii consists predominantly of 1,3-bound rhamnose residues with a substituent in the second position. The rhamnose residues in the polysaccharide fraction ofNostoc are connected by 1,3- and 1,2-glycosidic bonds. The lipid components of the LPSs fromO. hilderbrandtii andNostoc consist of palmitic and steric acids, with glucosamine and glucose.     

Alkaloids of Rauwolfia species growing in Vietnam

Reserpine, ajmaline, serpentine, ajmalicine, isoreserpiline, and other alkaloids have been isolated from the roots ofRauwolfia cambodiana Pierre ex Pitard,R. verticillata Baill. andR. serpentina Benth.R. vomitoria Afz. was the richest in alkaloids.     

Pheromones of insects and their analogs

From cyclohexene and caproaldehyde, using ozonolysis and the Knoevenagel reaction, we have synthesized hexadeca-7Z,11E-dien-l-yl acetate — the sex pheromone ofSitotroga cerealella and a component of the sex pheromone ofPectinophora gossypiella.     

Gas-chromatographic determination of the composition of the volatile components of the oleoresins of some species of conifers

Using the method of analytical GLC in a glass capillary column, the compositions have been studied of the volatile fractions of the oleoresins of five species of conifers:Larix decidua,Pinus strobus,Pinus mugo,Picea excelsa, andPinus abies. In the oleoresins 21 monoterpene and 22 sesquiterpene compounds were identified from their relative retention times and with the aid of additives. The main components of the volatile fractions of the oleoresins were α- and β-pinenes and 3-carene among the monoterpenes, and longifolene caryophyllene, δ- and γ-cadinenes and α-murolene among the sesquiterpene compounds. The quantitative analysis of the fractions was carried out by the method of internal normalization from averaged correlation coefficients.     

Size-dependent core-level spectroscopy of free neutral clusters

Studies of the electronic and geometric structure of free clusters are presented to highlight the application of core-level spectroscopy using synchrotron radiation to cluster physics. The study of electronic structure deals with the excitation of the C 1s electron to the Rydberg states of the molecule in CH₄ clusters and demonstrates the gradual evolution of the surface and bulk-specific spectral features with cluster size. A second study investigates the K-edge excitations in Ne clusters and is concerned with extracting structural information from the X-rays Absorption Near-Edge Structure (XANES).     

Lipids of the biomass ofRuta graveolens,grownin vivo andin vitro

A lower content of chlorophylls, phospholipids, and linolenic acid and a higher content of rutin, carotenoids, and xanthophylls in the biomass ofRuta graveolens L. obtainedin vitro has been found as compared with these indices from the epigeal part of the plant grownin vivo.     

Sepaconitine — A new alkaloid from Aconitum septentrionale

The structure of a new alkaloid sepaconitine isolated from the epigeal part ofAconitum septentrionale has been established on the basis of spectral characteristics.     

Phytoecdysteroids of plants of the genus Silene. XV. 2-Deoxy-α-ecdysone 22-O-benzoate from Silene wallichiana

A new phytoecdysteroid, 2-deoxy-α-ecdysone 22-O-benzoate, has been isolated from the epigeal organs ofSilene wallichiana Klotzch.     

Lipids of the fruit ofAcanthopanax sessiliflorus

In the lipids of the seeds and pericarp of the introduced speciesAcanthopanax sessiliflorus (Rupr. et Maxim.) Seem (familyAraliaceae), 23 classes of compounds have been detected, of which 19 have been identified. Sixteen of the classes have been studied. The lipids of the pericarp contain a more complex set of components than the seeds. Hydroxyacyldiacylglycerides, fatty acid methyl esters, and a complex group of pthalicacidesters have been detected in the familyAraliaceae for the first time. The fatty acid compositions of the seed and pericarp lipids are characterized by a high level of petroselinic acid.     

Alkaloids of Aconitum sajanense II. Structure of dehydroacosanine

The new alkaloid dehydroacosanine has been isolated from the roots ofAconitum sajanense Kumin, and its structure has been established by spectral and chemical methods.     

Oxygenated acids of the reserve lipids of Rumex paulsenianus

The composition of the fatty mono- and dihydroxy acids of the fruit ofRumex paulsenianus Rech. fil. (familyPolygonaceae) has been determined by a combination of IRS, UVS, GLC, and mass-spectrometric methods. (22) Monohydroxy acids of the C₁₄–C₂₀ series, including isomers and isologues, and four dihydroxy acids from C₁₈ to C₂₀, including a new isomeric 9-OH-10, 12–17:2 acid have been detected.     

Structures of cucumariosides C1 and C2 — Two new triterpene glycosides from the holothurian Eupentacta fraudatrix

Two new triterpene glycosides — cucmariosides C₁ and C₂ — have been isolated from the Far Eastern holothurianEupentacta (=Cucumaria)fraudatrix Djakonov et Baranova. Their structures have been established with the aid of¹³C NMR and PMR spectroscopy, partial acid hydrolysis, periodate oxidation, and methylation as 16β-acetoxy-3-{[3-O-methyl-β-D-xylopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)] [β-D-xylopyranosyl-(1→2)]-β-D-quinovopyranosyl-(1→2)-β-D-xylopyranosyloxy}holosta-7,23,24(cis)-triene and 16β-acetoxy-3-{[3-O-methyl-β-D-xylopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)] [β-D-xylopyranosyl-(1→2)]-β-D-quinovopyranosyl-(1→2)-β-D-xylopyranosyloxy}holosta-7,22,24(trans)-triene, respectively.     

Cis-Cycloprolylprolin-Anion-ein konfigurationsstabiles Carbanion

The racemisation ofcyclo-(l-Pro?l-Pro) (2) with metal amides in liq. ammonia was examined. The K-kation causes more extensive racemisation than Na-kation, which in turn is more effective than Li⁺. This, the racemisation of2 int-butyl alcohol with K⁺C₆H₅O^? and the data gained from corresponding deuterated medium show that the racemisation of2 proceeds in two steps: in the first, the less stabletrans-cyclo-(l-Pro?d-Pro) (3) is formed, followed by the rapid conversion of3 to a mixture ofcyclo-(l-Pro?l-Pro) andcyclo-(d-Pro?d-Pro) in the second step.     

Isoform specific gene auto-regulation via miRNAs: a case study on miR-128b and ARPP-21

In this study, we investigate whether miRNAs located within “host” protein-coding genes may regulate the expression of their host genes. We find that 43 of 174 miRNAs encoded within RefSeq genes are predicted to target their host genes. Statistical analysis of this phenomenon suggests that gene auto-regulation via miRNAs may be under positive selective pressure. Our analysis also indicates that several of the 43 miRNAs have a much lower expectation of targeting their host genes by chance than others. Among these examples, we identify miR-128b:ARPP-21 (cyclic AMP-regulated phosphoprotein, 21 kD) as a case in which both the miRNA and the target site are also evolutionarily conserved. We provide experimental support for this miRNA:target interaction via reporter silencing assays, and present evidence that this isoform-specific gene auto-regulation has been preserved in vertebrate species in order to prevent detrimental consequences of ARPP-21 over-expression in brain.     

Glycosides of marine invertebrates. VIII. Steroid glycosides of the holothurianIsostichopus badionotus

The steroid glycoside fraction ofIsostichopus badionotus, consisting of a mixture of D-xylosides of steroid alcohols, has been isolated by column chromatography on silica gel. The mixture of aglycones obtained after acid hydrolysis was separated with the aid of argentation chromatography into several fractions. GLC-MS analysis, and also the use of IR and¹³C NMR spectroscopy has shown that the steroid glycosides ofI. badionotus are xylosides of Δ⁰-, Δ⁷-, Δ²²-, and Δ^7.22-, C₂₇-, C₂₈-, and C₂₉-steroids of the cholestane series.     

5′-Phosphouridine as a source of terminal phosphate groups in oligonucleotides

A universal key component is proposed for the preparation of oligonucleotides with 3′- and 5′-terminal phosphate groups — 2′,3′-dibenzoyluridin-5′-yl (4-chlorophenylphosphate) (pU(Bz)₂), which is a potential source of the phosphate group. The condensation ofpU(Bz)₂ with the 5′-OH or the 3′-OH group of a protected oligonucleotide leads to the formation of oligodeoxyribonucleotides with 5′- or 3′-terminal uridine, respectively. The oxidation of the 2′,3′-cis-glycol group of the terminal uridine unit followed by β-elimination forms oligodeoxyribonucleotides with terminal phosphate groups.     

Amounts of arachidonic acid in the buds of Populus balzamifera in the course of the annual cycle

The paper gives information on the amount of arachidonic acid in the buds ofPopulus balzamifera. The presence of arachidonic acid in the buds was confirmed by TLC, GLC, coulometric titration, and an iodine number calculation. The dynamics of the amount of arachidonic acid in the buds during the annual cycle are given.     

Histones of the cotton plant. Molecular characteristics of histone H1

A characterization of the histones of two varieties of the cotton plant,Gossypium hirsutum andG. barbadense, has been given with the aid of various electrophoretic systems. Their molecular weights have been determined. An analysis has been made of the cleavage of histone H1 at tyrosine residues. The positive charge and the molecular length of histone H1 have been determined by the method of incomplete succinylation.