Carotenoids of Rhizobia. IV. Isolation and structure elucidation of the carotenoids of a mutant of Rhizobium lupini

The structures of the main carotenoid pigments from the mutant 1-207 of Rhizobium lupini were elucidated by spectroscopic techniques (UV./VIS., CD., 270 MHz ¹H-NMR., and MS.). Ten carotenoids were identified, namely β,β-carotene ( 1 ), β,β-caroten-4-one (echinenone, 2 ), β,β-carotene-4,4′-dione (canthaxanthin, 3 ), (3S)-3-hydroxy-β,β-caroten-4-one ((3S)-3-hydroxyechinenone, 4 ), (2R, 3R)-β,β-carotene-2,3-diol ( 5 ), (3S)-3-hydroxy-β,β-carotene-4,4′-dione ((3S)-adonirubin, 6 ), (2R, 3S)-2,3-dihydroxy-β,β-caroten-4-one ( 7 ), (2R, 3S)-2,3-dihydroxy-β,β-caroten-4,4′-dione ( 8 ), (2R, 3S, 2′R, 3′R)-2,3,2′,3′-tetrahydroxy-β,β-caroten-4-one ( 9 ) and the corresponding (2R, 3S, 2′R, 3′S)-4,4′-dione ( 10 ). Structures 5, 7, 8 and 10 have not been reported before. From the observed carotenoid pattern it is concluded that in this mutant the oxidation to 4-oxo compounds is favoured compared to the hydroxylation at C(3) and C(2).     

Opposid,vermutliche Struktur. Glykoside und Aglykone, 302. Mitt.

The hypothetical structure 1 is proposed for opposide (C₂₉H₄₄O₁₁), a new glycoside from the seeds of Acokanthera oppositifolia (LAM.) CODD. Opposide is derived from the new aglycone gratogenin, which is most probably the 1β, 3β, 5β, 11α, 14β-pentahydroxy-card-20:22-enolide ( 8 ) (C₂₃H₃₄O₇) and which is bound glycosidically through position 3 to the α-pyranosidic form of 6-desoxy-L-talose. The hydrolysis of opposide by HCl in acetone gave an anhydrogenin (C₂₃H₃₂O₆) instead of the intact aglycone. In analogy to the reaction sequence observed by VOLPP and TAMM for ouabagenin, the structure of the anhydrogenin is deduced to be that of a 3β, 5β, 14β-trihydroxy-1α, 11α-epoxy-card-20:22-enolide ( 6 ). The above mentioned structures are based on the course of acetylation and especially on NMR.-spectra.     

Viminolon,Strukturbeweis. Glykoside und Aglykone, 315. Mitteilung

Reduction of di-O-benzoyl-viminolon ( 1 ) with LiAlH₄ gave a mixture of 17-isopregn-5-ene-heptols. Treatment of this mixture with NaIO₄ produced the amorphous 12-O-formyl sarcostinketone (= 12-O-formyl-3β, 8β, 12β, 14β-tetrahydroxy androst-5-en-20-one) ( 4 ). This together with former results proves the structure of 1 .     

Gymnemagenin,vermutliche struktur Glykoside und Aglykone, 289. Mitteilung

Gymnemagenin, the aglycone obtained from gymnemic acid by fermentative degradation and alkaline hydrolysis, is probably a new hexahydroxy-triterpene. The proposed structures are derived mainly from data obtained by physical methods. Gymnemagenin is probably a 3β,15α(or 16β), 21β,22α,23,28- or 3β,15α,16β,21β(or 22α), 23,28-hexahydroxy-olean-12-ene. Further experimental information is necessary for decision concerning the correct structure.     

Alloglaucotoxigenin,Strukturbestimmung Glykoside und Aglykone, 280. Mitteilung

The structure of alloglaucotoxigenin is shown to be that of 3β, 14β, 15β-trihydroxy-19-oxo-5α-carda-20:22-enolide (IV) in the following way: The 19-oxo group could be eliminated by reduction of the corresponding mercaptal. The structure of the resulting 3β, 14β, 15β-trihydroxy-5α-carda-20:22-enolide, obtained in the acetylated form, was established through degradation and through partial synthesis by treatment of Δ¹⁴-anhydro-uzarigenin (XIII) with osmium tetroxide. The isomeric 3β,14α, 15α-trihydroxy-cardenolide was also formed in large quantities. The substance XI showed in its optical rotatory dispersion curve a positive, and substance XIV a negative COTTON effect.     

Glaucasides A-C, three saikosaponins from Atriplex glauca L. var. ifiniensis (Caball) Maire

From the roots of Atriplex glauca L. var. ifiniensis (Caball) Maire (syn. of Atriplex parvifolia Lowe var. genuina Maire), three new saikosaponins designated as glaucasides A-C (1-3) were isolated together with the known 3-O-β-D-glucopyranosyl-(1 → 2)-β-D-galactopyranosyl-saikogenin F (4). The structures of the new compounds were elucidated by extensive analysis of one-dimensional and two-dimensional NMR spectroscopy, FABMS, HR-ESIMS and chemical evidence as 13β,28-epoxy-16β,21β-dihydroxyolean-11-en-3β-yl O-β-D-[2-O-sulfate]-glucopyranosyl-(1 → 2)-α-L-arabinopyranoside (1), 13β,28-epoxy-16β,21β-dihydroxyolean-11-en-3β-yl O-β-D-[2-O-sulfate]-glucopyranosyl-(1 → 2)-α-L-arabinopyranosyl 21-O-{4-(secbutylamido)-butanoyl ester} (2) and 3-O-β-D-glucopyranosyl-(1 → 2)-β-D-galactopyranosyl saikogenin G (3). The cytotoxic activities of these compounds were evaluated against the HT-29 and HCT 116 human colon cancer cell lines.     

Steroid glycosides ofNicotiana tabacum seeds I. The structures of nicotianosides A,B, and E

Two steroid glycosides of the spirostan series — nicotianosides A and B — and one glycoside of the furostan series — nicotianoside E — have been isolated from the seeds ofNicotiana tabacum L. Nicotianoside A is (25S)-5α-spirostan-3β-ol 3-O-β-D-glucopyranoside, nicotianoside B is (25S)-5β-spirostan-3β-ol 3-O-[O-α-L-rhamnopyranosyl-(1→2)-gb-D-glucopyranoside], and nicotianoside E is (25S)-5α-furostan-3β,22α,26-triol 26-O-β-glucopyranoside 3-O-[O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside].     

Die sterischen Bedingungen der Fragmentierungsreaktion I. Teil. Stereoisomere 3-Chlortropane. Fragmentierungsreaktionen, 14. Mitteilung

The steric requirements for the synchronous fragmentation of γ-aminohalides as previously postulated have been confirmed by a study of the solvolysis of stereoisomeric 3β- and 3β-chloro-tropanes and -nortropanes. 3β-chloro-tropanes ( 7 a ) and 3β-chloro-nortropane ( 7 b ), which fulfil the stereoelectronic requirements, undergo quantitative fragmentation in 80 vol.% ethanol. They react 1.35 × 10⁴ and 1.35 × 10³ times, respectively, as fast as the ‘homomorphous’ exo-3-chloro-bicyclo[3.2.1]octane ( 12 a ). Fragmentation therefore takes place by the synchronous mechanism.     

Stapelogenin,vermutliche Struktur. Glykoside und Aglykone, 276. Mitteilung

Stapelogenin, C₂₁H₃₀O₄, shows a double bond and two hydroxyl groups which can be acetylated. On the grounds of UV.-, IR.-, and NMR-spectra as well as mass spectra, the probable structure is that of a 3β, 12β-dihydroxy-(18, 20β), (14β, 20α)-diepoxy-Δ⁵-pregnene ( 1 ). The exact position of the hydroxyl group, assumed to be 12β, is particularly unsure, as it could also be situated 11α- or 12α-position.     

Glykoside von Marsdenia erecta R. Br. 2. Mitteilung: Versuche zur Strukturbestimmung der Genine. Glykoside und Aglykone, 330. Mitteilung

Structures for the genins of the ester glycosides of Marsdenia erecta are suggested. They are based on the behaviour in alkaline hydrolysis of these ester glycosides, their NMR. and mass spectra and ORD. data. All genins are derived from three acyl-free pregnane derivatives, i.e. drevogenin-P ( 1 ), 17 β-marsdenin ( 3 ) and marsectohexol ( 7 ). The structure of 1 is known, 3 and 7 are new compounds, i.e. 3 = 3β,8β,11α,12β,14β-pentahydroxy-Δ⁵-pregnen-20-one and 7 = 3β,8β,11α,12β,14β,20ξ-hexahydroxy-Δ⁵-pregnene. Formulae 13–17 were attributed to the acyl-genins A-1, A-2, A-3, A-4 and A-5, but only two of them were pure compounds, i.e. acyl-genin A-3 = 11,12-di-O-tiglyl-17β-marsdenin ( 15 ) and acyl-genin A-5 = 11,12-di-O-acetyl-marsectohexoi ( 17 ). Acyl-genin A-1 is a mixture of the two esters 13a + 13b derived from drevogenin-P, and similarly acyl-genin A-2 is a mixture of the esters 14a + 14b derived from 17β-marsdenin. The poorly characterised acyl-genin A-4 is most probably a mixture of the esters 16a + 16b , also derived from 17β-marsdenin.     

Struktur der Drebyssobiose,Lilacinobiose und Viminose: Desoxyzucker, 45. Mitteilung

The structures of the following three disaccharides, isolated from Asclepiadaceae, have been elucidated: Drebyssobiose (1) = 4–0-(3–0-methyl-6-deoxy-β-d-allopyranosyl)-d-digitoxose, lilacinobiose (7) = 4-O-(3-O-methyl-6-deoxy-β-d-glucopyranosyl)-d-cymarose, and viminose (13) = 4-O-(3-O-methyl-6-deoxy-β-d-glucopyranosyl)-d-digitoxose.     

Three new flavonoid glycosides, byzantionoside B 6'-O-sulfate and xyloglucoside of (Z)-hex-3-en-1-ol from Ruellia patula

Three new flavonoid glycosides, demethoxycentaureidin 7-O-β-D-galacturonopyranoside, pectolinarigenin 7-O-α-L-rhamnopyranosyl-(1?→4″)-β-D-glucopyranoside and 7-O-α-L-rhamnopyranosyl-(1?→4″)-β-D-glucuronopyranoside, a new megastigmane glucoside, byzantionoside B 6'-O-sulfate, and a new (Z)-hex-3-en-1-ol O-β-D-xylopyranosyl-(1″→2')-β-D-glucopyranoside, were isolated from leaves of Ruellia patula JACQ., together with 12 known compounds, β-sitosterol glucoside, vanilloside, bioside (decaffeoyl verbascoside), acteoside (verbascoside), syringin, benzyl alcohol O-β-D-xylopyranosyl-(1″→2')-β-D-glucopyranoside, cistanoside E, roseoside, phenethyl alcohol O-β-D-xylopyranosyl-(1″→2')-β-D-glucopyranoside, (+)-lyoniresinol 3α-O-β-D-glucopyranoside, isoacteoside and 3,4,5-trimethoxyphenol O-α-L-rhamnopyranosyl-(1″→6')-β-D-glucopyranoside. Their structures were elucidated by means of spectroscopic analyses.     

Flavonoids ofDatisca cannabina. V. Datiscanin — A new glycoside of datiscetin

The new flavonoid glycoside datiscanin has been isolated from the herbage ofDatisca cannabina L., and the structure of 2′,3,5,7-tetrahydroxyflavone 3-0-β-D-glucopyranoside has been established for it. After datiscin (datiscetin 3-rutinoside), this is the second datiscetin glycoside found in nature.     

Die Struktur der Drevogenine. 2. Mitteilung Struktur von Drevogenin P. Glykoside und Aglykone, 278. Mitteilung

Drevogenin A was converted in several steps (acetylation, hydrogenation, dehydration, hydrogenation, the haloform reaction and energetic alkaline hydrolysis) into 3β, 11α, 12β-trihydroxy-5α-etianic acid, which could be characterised by its crystalline methyl ester ( 15 ) and its tri-O-acetyl methyl ester ( 16 ). The same acid was obtained by partial synthesis starting from hecogenin. Taking into consideration earlier results [1], the structure of drevogenin P is proved to be 3β, 11α, 12β, 14β-tetrahydroxy-20-oxo-Δ⁵-pregnene ( 7 ). Energetic hydrolysis of dihydro-3-O-acetyldrevogenin A gave a mixture of 17αH- and 17βH-desacyl-kondurangogenin A, which were obtained in crystalline form after separation by chromatography. The only difference between the basic structures of the drevogenins and kondurangogenin A is the presence of a double bond in the 5-position in the former.     

Potential bile acid metabolites. 1. The epimeric 3ϵ,7α,12β-trihydroxy-5β-cholanic acids. Raney nickel as an epimerizing catalyst.

The epimeric 3α,7α,12β- and 3β,7α,12β-trihydroxy-5β-cholanic acids have been prepared. Under ambient hydrogenation conditions with Raney nickel as catalyst the axial 3β-ester ($\text{4b}$) is epimerized to the 3α-compound ($\text{2b}$).     

A new aryl glycoside from Euphorbia helioscopia L.

A new aryl glycoside,3″-O-galloyl-benzyl-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside,was isolated from Euphor- bia helioscopia L.,and its structure was elucidated on the basis of various spectroscopic data analysis.     

Two Novel Triterpenoids from Portulaca oleracea L.

Two novel triterpenoids, (2α,3α)‐3‐{[4‐O‐(β‐D ‐glucopyranosyl)‐β‐D ‐xylopyranosyl]oxy}‐2,23‐dihydroxy‐30‐methoxy‐30‐oxoolean‐12‐en‐28‐oic acid ( 1 ) and (2α,3α)‐2,23,30‐trihydroxy‐3‐[(β‐D ‐xylopyranosyl)oxy]olean‐12‐en‐28‐oic acid ( 2 ) were isolated from Portulaca oleracea L., and they both showed weak cytotoxic activity assayed with the MTT method.     

Struktur der Pachybiose und Asclepobiose. Desoxyzucker, 44. Mitteilung

Pachybiose (1) is shown to be 4-O-(3-O-methyl-6-deoxy-β-D -allopyranosyl)-D -oleandrose and asclepobiose (14) 4-O-(3-O-methyl-6-deoxy-β-D -allopyranosyl)-D -cymarose.     

Triterpene glycosides ofAstragalus and their genins. III. Cycloasgenin a fromAstragalus taschkendicus

The new isoprenoid cycloasgenin A has been isolated from the roots of the plantAstragalus taschkendicus C. Bge., and its structure has been established on the basis of chemical transformations and spectral characteristics as 6α,11α,16β, 25-tetrahydroxy-20(S), 24(R)-epoxycycloartan-3-one.     

Synthesis of ecdysone. 3. On insect hormones. Syntheses of 2-beta, 3-beta, 14-alpha-trihydroxy-6-keto-delta-7-A-B-cis-steroids

The synthesis of the tetracyclic skeleton of ecdysone with correct stereochemistry and substitution is described. 22,25-Didehydroxy-ecdysone and methyl (20S)-2β,3β-dihydroxy-6-oxo-5β-pregn-7-ene-20-carboxylate have been prepared. The latter is a key intermediate in the synthesis of ecdysone.