Biotransformation of paeonol by Panax ginseng root and cell cultures

Panax ginseng root and cell cultures were shown to biotransform paeonol (1) into its 2-O-β-d-glucopyranoside (2). P. ginseng root cultures were also able to biotransform paeonol (1) into its 2-O-β-d-xylopyranoside (3), 2-O-β-d-glucopyranosyl(1 → 6)-β-d-glucopyranoside (4) and 2-O-β-d-xylopyranosyl(1 → 6)-β-d-glucopyranoside (5), and its demethylated derivate, 2′,4′-dihydroxyacetophenone (6). Compounds 3 and 4 are new glycosides. It is the first example that the administrated compound was converted into its xylopyranoside by plant biotransformation.     

Cycloartane triterpene glycosides from Astragalus trigonus

Three new cycloartane glycosides, trigonoside I, II and III, and the known astragalosides I and II were isolated from the roots of Astragalus trigonus. The structures of the new glycosides were totally elucidated by high field (600 MHz) NMR analyses as cycloastragenol-6-O-β-xylopyranoside, cycloastragenol-3-O-[-l-arabinopyranosyl(1 → 2)-β-d-xylopyranosyl]-6-O-β- d-xylopyranoside and cycloastragenol-3-O-[-l-arabinopyranosyl(1 → 2)-β-d-(3-O-acetyl)-xylopyranosyl]-6-O-β-d-xylopyranoside.     

Triterpenoidal saponins from Dumasia Truncata

Extraction of the aerial parts of Dumasia truncata Sieb et Zucc. afforded two new triterpenoidal saponins, together with four known ones. The structures of the new compounds were elucidated by spectral analysis as 3-O--l-rhamnopyranosyl-(1 → 3)-β-d-glucuronopyranosy-28-O-β-d-glucopyransoyl hederagenin and 3-O-β-d-xylopyranosyl-(1 → 2)-[-l-rhamnopyranosyl(1 → 3)]-β-d-glucuronopyranosyl oleanic acid.     

An acetophenone and three naphthalides from turkish Rhamnus libanoticus

A new acetophenone glycoside and two new naphthalide glycosides have been isolated from the bark of Turkish Rhamnus libanoticus together with 7-hydroxy-5-methoxyphthalide 7-O-β-D-glucoside. The structures of the new compounds were elucidated by spectroscopic methods as 2,6-dihydroxy-4-methoxyacetophenone 2-O-β- rutinoside, 8,9-dihydroxy-6-methoxynaphthalide 8-O-β-rutinoside, 8,9-dihydroxy-6-methoxynaphthalide 8-O-/3b-D glucoside, respectively.     

Chemotaxonomic significance of flavonoids and phenolic acids in the Hieracium rohacsense group (Hieracium sect. Alpina; Lactuceae, Compositae)

Five apomictic taxa from the Hieracium rohacsense group were studied for their phenolic constituent composition. The following substances represent dominant compounds in the leaves: chlorogenic acid, 3,5-dicaffeoylquinic acid, luteolin 7-O-β- -glucopyranoside, luteolin 4′-O-β- -glucuronopyranoside and apigenin 4′-O-β- -glucuronopyranoside. Within the group only quantitative differences were found, luteolin 7-O-glucoside being the most important chemotaxonomic marker. Each taxon has its own specific quantitative pattern, invariable within the taxon. Based on these characteristic profiles, H. rohacsense can be distinguished from a closely related and still undescribed taxon from Mt. Pip Ivan. The proportion of luteolin 7-O-glucoside to apigenin 4′-O-glucuronoside also clearly separates the individuals of two morphologically close species—H. ratezaticum and H. pseudocaesium, which corresponds to a few slight but recognisable morphological and phenological characteristics. The ontogenetic stage of leaf development and seasonal variation are also important factors, which must be taken into consideration, as the quantity of the substances changes during leaf ontogeny and with season.     

Acylated flavonol diglucosides from Lotus polyphyllos

Three acylated flavonol diglucosides, kaempferol 3-O-β-(6″-O-E-p-coumaroylglucoside)-7-O-β-glucoside; quercetin 3-O-β-(6″-O-E-p-coumaroylglucoside)-7-O-β-glucoside; isorhamnetin 3-O-β-(6″-O-E-p-coumaroylglucoside)-7-O-β-glucoside were isolated from the whole plant aqueous alcohol extract of Lotus polyphyllos. The known 3,7-di-O-glucosides of the aglycones kaempferol, quercetin and isorhamnetin were also characterized. All structures were established on the basis of chemical and spectral evidence.     

Further studies on the NADH oxidase of the cytoplasmic membrane of Mycobacterium tuberculosis

The cytoplasmic membrane of the H₃₇Ra strain of Mycobacterium tuberculosis has been isolated free of cell wall.

These membrane preparations contain very small quantities of cytochromes c, b and cytochrome oxidase. The cytochrome c is not extracted by any method attempted. The cytochrome b is reducible only by dithionite and is believed not to be involved in the direct transfer of electrons during the oxidation of NADH by these preparations. The NADH oxidase activity of the membrane is inhibited by high concentrations of cyanide and also by 2-(n-heptyl)-4-hydroxyquinoline-N-oxide (HQNO). The cytochrome oxidase of the membrane contains both cytochromes a and a₃ and is present in low concentrations relative to cytochrome c. The cytochrome a₃ component was identified by characteristic complexes with both CO and cyanide and shows a γ-band absorption maximum at a slightly lower wavelength than the cytochrome oxidase of mammalian mitochondria (442 nm vs. 445 nm). The functional activity of the cytochrome oxidase is indicated by the inhibition of reoxidation of reduced cytochromes c and a in the presence of cyanide.     

Respiratory cytochromes of Euglena gracilis

1. 1. Difference spectra of whole cells and of a particulate fraction of a streptomycin-bleached strain of Euglena gracilis showed the presence of a b-type cytochrome, cytochrome b (561 Euglena), and an a-type cytochrome, cytochrome a-type (609 Euglena). The cytochromes were characterized by pyridine hemochromogen formation and were found associated with a particulate fraction enriched with mitochondria.

2. 2. Both b-type and a-type cytochromes were reduced by succinate, oxidized by oxygen and reacted with a soluble c-type cytochrome, cytochrome c-type (556 Euglena), in reversible oxidation-reduction reactions. The steady-state level of reduction for each cytochrome was 92, 22 and 5% of the anaerobic level for the b-type, c-type and a-type cytochrome, respectively.

3. 3. Oxidation of c-type and a-type cytochromes was completely inhibited by cyanide, although respiration of a particulate fraction was only 60% inhibited by the same concentration of cyanide. Antimycin A inhibited respiration by up to 70% but completely inhibited reduction of the c-type cytochrome.

4. 4. The data suggest that electron transfer in the respiratory pathway of Euglena involves the b-, c- and a-type cytochrome in a direct sequence. The cyanide and antimycin A-insensitive oxidation pathway is considered to involve a more direct oxidation of the b-type cytochrome.

Flavonol glycosides from Pteridium aquilinum

Two new flavonol glycosides from aerial parts of Pteridium aquilinum were identified as quercetin 3-O-β-laminaribioside and isorhamnetin 3-o-β-laminaribioside by chemical and spectroscopic methods.     

Biocatalysis in ionic liquids: the stereoconvergent hydrolysis of trans-β-methylstyrene oxide catalyzed by soluble epoxide hydrolase

Soluble epoxide hydrolase (sEH) was shown to catalyze hydrolysis of epoxides using the ionic liquids (ILs) [bmim][PF₆], [bmim][N(Tf)₂], and [bmim][BF₄] (where bmim=1-butyl-3-methylimidazolium, PF₆=hexafluorophosphate, N(Tf)₂=bis(trifluoromethylsulfonyl)imide, and BF₄=tetrafluoroborate) as reaction medium. Reaction rates were generally comparable with those observed in buffer solution, and when the cress enzyme was used the hydrolysis of trans-β-methylstyrene oxide gave, through a stereoconvergent process, the corresponding optically active (1S,2R)-erythro-1-phenylpropane-1,2-diol.     

Pregnane glycosides from fruits of Balanites aegyptiaca

From the mesocarp of Balanites aegyptiaca fruits, two pregnane glycosides were isolated. One is new and identified as pregn-5-ene-3β,16β,20(R)-triol 3-O-(2,6-di-O--l-rhamnopyranosyl)-β-d-glucopyranoside (balagyptin), while the other is known and assigned as pregn-5-ene-3β,16β,20(R)-triol 3-O-β-d-glucopyranoside.     

The crystal and molecular structures of lithium trimethylenediaminetetraacetatoferrate(III) trihydrate Li[Fe(trdta)]·3H2O and sodium ethylenediamine-N,N′-diacetato-N,N′-di-3-propionatoferrate(II) pentahydrate Na[Fe(eddda)]·5H2O

The crystal structures of Li[Fe(trtda)]·3H₂O and Na[Fe(eddda)]·5H₂O (trtda = trimethylenediaminetetraacetate and eddda = ethylenediamine-N,N′-diacetate-N,N′-di-3-propionate) have been determined by single crystal X-ray diffraction techniques. The former crystal was monoclinic with the space group P2₁/n,a = 17.775(3),b = 10.261(1),c = 8.883(2)Å, β = 95.86(4)° and Z = 4. The latter was also monoclinic with the space group P2₁/n,a = 6.894(2),b = 20.710(6),c = 13.966(3)Å, β = 101.44(2)° and Z = 4. Both complex anions were found to adopt an octahedral six-coordinated structure with all of six ligand atoms of trdta⁴⁻ or eddda⁴⁻ coordinated to the Fe(III) ion, unlike the corresponding edta⁴⁻ complex which is usually seven-coordinate with the seventh coordination site occupied by H₂O. Of the three geometrical isomers possible for the eddda complex, the trans(O₅) isomer was actually found in the latter crystal. Factors determining the structural types of metal–edta complexes are discussed in detail.     

Six new C21 steroidal glycosides from Asclepias curassavica L

Six new C₂₁ steroidal glycosides, named curassavosides A–F (3–8), were obtained from the aerial parts of Asclepias curassavica (Asclepiadaceae), along with two known oxypregnanes, 12-O-benzoyldeacylmetaplexigenin (1) and 12-O-benzoylsarcostin (2). By spectroscopic methods, the structures of the six new compounds were determined as 12-O-benzoyldeacylmetaplexigenin 3-O-β-d-oleandropyranosyl-(1 → 4)-β-d-digitoxopyranoside (3), 12-O-benzoylsarcostin 3-O-β-d-oleandropyranosyl-(1 → 4)-β-d-digitoxopyranoside (4), sarcostin 3-O-β-d-oleandropyranosyl-(1 → 4)-β-d-canaropyranosyl-(1 → 4)-β-d-oleandropyranosyl-(1 → 4)-β-d-digitoxopyranoside (5), sarcostin 3-O-β-d-oleandropyranosyl-(1 → 4)-β-d-canaropyranosyl-(1 → 4)-β-d-canaropyranosyl-(1 → 4)-β-d-digitoxopyranoside (6), 12-O-benzoyldeacylmetaplexigenin 3-O-β-d-glucopyranosyl-(1 → 4)-β-d-oleandropyranosyl-(1 → 4)-β-d-canaropyranosyl-(1 → 4)-β-d-oleandropyranosyl-(1 → 4)-β-d-digitoxopyranoside (7), and 12-O-benzoylsarcostin 3-O-β-d-glucopyranosyl-(1 → 4)-β-d-oleandropyranosyl-(1 → 4)-β-d-canaropyranosyl-(1 → 4)-β-d-oleandropyranosyl-(1 → 4)-β-d-digitoxopyranoside (8), respectively. All compounds (1–8) were tested for in vitro cytotoxicity; only compound 3 showed weak inhibitory activity against Raji and AGZY cell lines.     

Pustulan and branched β-galactofuranan from the phytopathogenic fungus Guignardia citricarpa, excreted from media containing glucose and sucrose

Guignardia citricarpa is a phytopathogenic fungus and the causal agent of citrus black spot. Incubation in a semi-defined media resulted in formation of exopolysaccharides [EPS(s)]. A medium containing glucose gave rise to a (1→6)-linked β-glucan (200 kD), pustulan, which was characterized by NMR and methylation analysis. A sucrose-containing medium provided a homogalactan (376 kD) and methylation analysis showed nonreducing end- (20%), 6-O- (53%) and 5,6-di-O-substituted Galf units (27%). An HMQC spectrum of the homogalactan showed C-1/H-1 signals at δ 108.2/4.820, 108.3/4.820 and 107.1/5.079, corresponding to three types of β- -Galf units. A DEPT analysis showed inverted signals (CH₂) at δ 67.8 and 67.2, corresponding to 6-O-substituted β- -Galf units, whereas a C-5 signal at δ 77.0 suggests 5-O-substitution, confirming a novel structure for a β-galactofuranan.     

Iridoid glucosides from Thunbergia laurifolia

Two iridoid glucosides, 8-epi-grandifloric acid and 3′-O-β-glucopyranosyl-stilbericoside, were isolated from the aerial part of Thunbergia laurifolia along with seven known compounds, benzyl β-glucopyranoside, benzyl β-(2′-O-β-glucopyranosyl) glucopyranoside, grandifloric acid, (E)-2-hexenyl β-glucopyranoside, hexanol β-glucopyranoside, 6-C-glucopyranosylapigenin and 6,8-di-C-glucopyranosylapigenin. Strucural elucidation was based on the analyses of spectroscopic data.     

Streptococcus pneumoniae type XIV polysaccharide: synthesis of a repeating branched tetrasaccharide with dioxa-type spacer-arms

β-Glycosides of 2-acetamido-2-deoxy- -glucopyranose were synthesized, using either 7-methoxycarbonyl-3,6-dioxa-1-heptanol or 8-azido-3,6-dioxa-1-octanol. Selective β-lactosylation of 7-methoxycarbonyl-3,6-dioxaheptyl 2-acetamido-3-O-benzyl-2-deoxy-β- -glucopyranoside with hepta-O-acetyl-lactosyl-trichloroacetimidate, followed by β-galactosylation of the secondary hydroxyl group with O-(2,3,4,6-tetra-O-acetyl-- -galactopyranosyl)trichloroacetimidate, catalytic hydrogenolysis, and O-deacetylation, gave 7-methoxycarbonyl-3,6-dioxaheptyl 2-acetamido-2-deoxy-4-O-β- -galactopyranosyl-6-O-(4-O-β- -galactopyranosyl-β- -glucopyranosyl)β- -glucopyranoside. Selective β-lactosylation of 8-azido-3,6-dioxaocytl 2-acetamido-3-O-benzyl-2-deoxy-β- -glucopyranoside with hepta-O-acetyl-lactosyl bromide in the presence of silver triflate, followed by condensation with 2,3,4,6-tetra-O-acetyl-- -galactopyranosyl bromide in the presence of silver triflate, catalytic hdyrogenolysis, and O-deacetylation, gave 8-azido-3,6-dioxaoctyl 2-acetamido-2-deoxy-4-O-β- -galactopyranosyl-6-O-(4-O-β- -galactopyranosyl-β- -glucopyranosyl)-β- glucopyranoside.     

A triterpenoid and its saponin from Phytolacca esculenta.

A new triterpenoid, esculentagenin, and its glycoside, esculentoside M, were isolated from the roots of Phytolacca esculenta and characterized as 11-oxo-3-O-methyloleanata-12-en-2β,3β,23-trihydroxy-28-oic acid and 3-O-[β - -glucopyranosyl (1→4)-β- -Xylopyranosyl]-28-O-β- -glucopyranosyl-11-oxo-30-methyloleanate-12-en-2β,3β,23-trihydroxy-28-oic acid by spectral and chemical evidence.     

Application of the hydro(solvo)thermal technique to the synthesis of metal carbonyl chalcogenide clusters Part 3. Synthesis, structural characterization, and spectroscopic studies of the clusters [{M(CO)4}n(MS4)] (M = Mo, W; N=1, 2)

The methanothermal reactions of M(CO)₆ (M = Mo, W) with Na₂S₂ gave a series of homonuclear clusters [{M(CO)₄}_n(MS₄)]²⁻ (M=Mo, W; N=1, 2), i.e. (Ph₄P)₂[(CO)₄Mo(MoS₄)] (I), (Ph₄P)₂[(CO)₄W(WS₄)] (II), (Ph₄P)₂[(CO)₄Mo(MoS₄)Mo(CO)₄] (III) and (Ph₄P)₂[(CO)₄W(WS₄)W(CO)₄] (IV). The two dimers, I and II, as well as the two trimers, III and IV, are isostructural to each other, respectively. All compounds crystallize in the triclinic space group with Z=2. The cell dimensions are: a=12.393(8), b=19.303(9), c=11.909(6) Å, =102.39(5), β=111.54(5), γ=73.61(5)°, V=2522(3) ų at T=23 °C for I; a=12.390(3), b=19.314(4), c=11.866(2) Å, =102.66(2), β=111.49(1), γ=73.40(2)°, V=2511(1) ų at T=23 °C for II; a=11.416(3), b=22.524(4), c=10.815(4) Å, =91.03(2), β=100.57(3), γ=88.96(2)°, V=2733(1) ų at T=−100 °C for III, a=11.498(1), b=22.600(4), c=10.864(3) Å, =90.92(2), β=100.85(1), γ=88.58(1)°, V=2771(2) ų at T=23 °C for IV. The dimers are each formed by the coordination of the tetrathiometalate as a bidentate chelating ligand to an M(CO)₄ fragment while addition of another M(CO)₄ fragment to the dimers results in the trimers. All compounds contain both tetrahedral and octahedral metal centers with the formal 6+ and 0 oxidation states, respectively.     

Chalconoid and stilbenoid glycosides from Guibourtia tessmanii

Phytochemical studies on the stem bark of Guibourtia tessmanii yielded a dihydrochalcone glucoside, 2′,4-dihydroxy-4′-methoxy-6′-O-β-glucopyranoside dihydrochalcone and a new stilbene glycoside, 3,5-dimethoxy-4′-O-(β-rhamnopyranosyl-(1→6)-β- glucopyranoside) stilbene besides the known pterostilbene. Their structures were established on the basis of one and two dimensional NMR spectroscopic techniques, FABMS and chemical evidence.     

Influence du pH sur la synthèse de l''oxidase (cytochrome a3) chez Bacillus coagulans, microorganisme thermophile, capable d'' “adaptation respiratoire”

In a new series of experiments on Bacillus coagulans (ATCC 11.369), it was demonstrated that this organism possesses a respiratory system with cytochromes b, c₁, c, (a+a₃) and also cytochrome o. A small decrease in the pH of the growth medium from 6.5 to 5.5 increases the respiratory activity by a factor of 4 and induces a variation of the absorption ratio [₆₀₃ (a+a₃)]/[₅₆₀ (b+c)] resulting in a preponderant increase in the ₆₀₃ absorption. The kinetic studies of the respiratory system synthesis during the phenomenon of “respiratory adaptation” have shown that lowering the pH of the adaption medium has the same effect. Spectral studies of membrane fractions (red dithionite) with or without carbon monoxide showed a preferential synthesis of oxidase a₃.