A Closer Look at the Hydroiodination of Propiolic Acid

The crystal structures of cis‐3‐iodoacrylic acid (1), trans‐3‐iodoacrylic acid (2), trans‐3‐iodoacrylic acid methyl ester (3), 3,3‐diiodopropanoic acid (4), and trans‐2,3‐diiodoacrylic acid (5) are reported. Compounds 1 and 2 are the kinetic and thermodynamic products, respectively, of the hydroiodination of propiolic acid. Compound 4 results from addition of a second equivalent of hydroiodic acid to 1 or 2, whereas 5 results from the addition of trace elemental iodine to propiolic acid.     

Cytotoxic constituents from Helicteres hirsuta collected in Vietnam

Abstract

Phytochemical study on the extract of Vietnamese medicinal plant Helicteres hirsuta Lour. has led to the isolation and structural elucidation of twelve secondary metabolites, 3-O-trans-caffeoylbetulinic acid (1), 3β-benzoylbetulinic acid (2), betulinic acid methyl ester (3), betulinic acid (4), lupeol (5), 4-hydroxybenzoic acid (6), 3,4-dihydroxybenzoic acid methyl ester (7), 4-hydroxy-3,5-dimethoxybenzoic acid (8), 5,8-dihydroxy-7,4′-dimethoxyflavone (9), isoscutellarein 4’-methyl ether 8-O-β-D-glucopyranoside (10), methyl caffeate (11) and stigmasterol (12). Especially, compound 2 was reported as a new natural product. Their structures were elucidated by a combination of 2D NMR and ESI-FT-ICR-MS spectroscopies. Furthermore, eight compounds were tested for their cytotoxicity against five cancer cell lines (Hela, HepG2, SK-LU-1, AGS and SK-MEL-2). The results showed that compounds (1, 3-5, 9) have moderate activities. This is the first study on the chemical constituents and their cytotoxicity of the Vietnamese Helicteres hirsuta L.     

A new coruleoellagic acid derivative from stems of Rhodamnia dumetorum

A new coruleoellagic acid derivative, 3,3′,4,4′,5′-pentamethylcoruleoellagic acid (1) together with nine known compounds, hexamethylcoruleoellagic acid (2), 3,4,3′-tri-O-methylellagic acid (3), heptaphylline (4), 7-methoxymukonal (5), dentatin (6), sinapaldehyde (7), gallic acid (8), 2,6-dimethoxy-4H-pyran-4-one (9) and β-sitosterol (10) were isolated from the stems of Rhodamnia dumetorum. Their structures were identified by physical and spectroscopic data (IR, 1D and 2D NMR, and MS). Compounds 1, 2 and 7-10 were tested for antibacterial activity against six pathogenic bacterial strains (Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, and Methicillin resistant S. aureus (MRSA)).     

Strukturelle Abwandlungen anN-Acetylneuraminsäure, 3

From methyl-5-acetylamino-7,8-anhydro-4,9-O-bis-(t-butyldimethylsilyl)-3,5-dideoxy--D-glycero-D-galacto-2-nonulopyranosidonic acid methylester (1) the derivatives1 a and1 b were obtained by removing the 9-O-(t-butyldimethylsilyl)group withBu ₄NF, followed by acetylation. Treatment of1 b with 80% acetic acid and acetanhydride/pyridine yields the 8-epi-N-acetylneuraminic acid derivative2 a and the 7-epi-N-acetylneuraminic acid derivative3 a in a ratio of 3:1 (Scheme 1). The structure elucidation of2 b was achieved by converting2 b via the 4,9-bis-O-(tBDMSi)-8-O-tosyl-derivative2 d into the epoxide1 (Scheme 2). Using the same sequence the epoxides4 and5 were transformed into theN-acetylneuraminic acid derivative6 a and the 7,8-bis-epi-N-acetylneuraminic acid derivative7 a (Scheme 3). After treatment with sodium hydroxide and 0.025m HCl and Dowex 50 H⁺ the 8-epi-, 7-epi- and 7,8-bis-epi-N-acetylneuraminic acids2,3, and7 were obtained. These three compounds were tested withCMP-N-acetylneuraminic acid synthetase.

Herrn KollegenK. Schlögl mit den besten Wünschen zum 60. Geburtstag.     

PHOSPHONOMETHYLATION OF AMINOALKANOLS PREPARATION OF 4-(PHOSPHONOMETHYL)-2-HYDROXY-2-OXO-1,4,2-OXAZAPHOSPHORINANES1

Abstract

Treatment of aminoalkanols 1 with phosphorous acid and formaldehyde in presence of conc. hydrochloric acid gave mixtures of [(2-hydroxy alkyl)imino] dimethylene diphosphonic acids 3 and 4-(phosphonomethyl)-2-hydroxy-2-oxo-1,4,2-oxazaphosphorinanes 2 from which 2 were isolated as crystalline solids. Similar treatment of 2-amino-2-methyl-1,3-propanediol 8 gave a complex mixture from which dimethylene diphosphonic acid of 5-amino-5-methyl-1,3-dioxane 9 was isolated. 2-Aminoethanethiol, when subjected to phosphonomethylation. gave an unexpected novel quarternary nitrogen product 11. N-Alkylaminoalkanols 4 on phosphonomethylation gave 3:1 mixtures of [N-alkyl-N-(2-hydroxyalkyl)amino] methane phosphonic acid 6 and N-alkyl-2-hydroxy-2-oxo-1,4,2-oxazaphosphorinane 5. Treatment of the crude mixtures of 5 and 6 with aqueous sodium hydroxide gave disodium salts of [N-alkyl-N-(2-hydroxyalkyl)amino] methanephosphonic acid 7. The ratio of the cyclic to the open chain structures obtained as well as the formation of any unexpected novel products is dependent on the structure of the aminoalkanol that is phosphonomethylated. The ¹H, ¹³C and ³¹P spectra are reported for all new compounds.     

Two new labdane diterpenoids from the rhizomes of Isodon yuennanensis

Two new labdane diterpenoids, s-trans-8(17),12E,14-labdatrien-20-oic acid (1), s-trans-12E,14-labdadien-20,8β-olide (2), along with 10 known compounds, hinokiol (3), ursonic acid (4), 2α,3α-dihydroxyolean-12-en-28-oic acid (5), 2α,3β,23-trihydroxyolean-12-en-28-oic acid (6), ethyl 3-(3,4-dihydroxyphenyl)lactate (7), ethyl rosmarinate (8), (Z,E)-2-(3,4-dihydroxyphenyl)ethenyl caffeic ester (9), tridecanoic acid (10), β-sitosterol (11) and daucosterol (12), were isolated from the 70% acetone extract of the rhizomes of Isodon yuennanensis. Their structures were elucidated based on the analyses of extensive spectroscopic data and physicochemical properties.     

A new butanolide from the leaves of <Emphasis Type="Italic">Cinnamomum reticulatum</Emphasis>

A new butanolide, isoreticulide ((4R,3E)-4-hydroxy-5-methylene-3-octadecylidenedihydrofuran-2-one) (1), along with nine compounds including one sesquiterpenoid, (3-methoxy-5H-9,11dioxabenzo[3,4]cyclohepta[1,2-f])inden-7-yl)-methanol (2); six benzenoids, p-hydroxybenzoic acid (3), p-hydroxybenzaldehyde (4), protocatechuic acid (5), ferulic acid (6), trans-methyl p-coumarate (7), and p-dihydrocoumaric acid (8), and two amides, N-trans-feruloyltyramine (9) and dihydroferuloyltyramine (10), were isolated from the leaves of Cinnamomum reticulatum Hayata (Lauraceae). These compounds were characterized and identified by physical and spectral evidence.     

A novel sesquiterpenoid from the leaves of <Emphasis Type="Italic">Cinnamomum subavenium</Emphasis>

A novel sesquiterpenoid, subamol ((3-methoxy-5H-9,10-dihydroxybenzo[3,4]cyclohepta[1,2-f])inden-7-yl)methanol)) (1), along with six compounds, including one ionone: (+)-abscisic acid (2); and five benzenoids: syringaldehyde (3), trans-coumaric acid (4), cis-coumaric acid (5), vanillic acid (6), and p-hydroxybenzoic acid (7), were isolated from the leaves of Cinnamomum subavenium Miq (Lauraceae). These compounds were identified and characterized by physical and spectral evidence.     

Two new triterpenoids from the seeds of blackberry (Rubus fructicosus)

Two new ursane-type triterpenoids (1, 2) attached to isopropylidenedioxy group were isolated from the seeds of blackberry (Rubus fructicosus L., Rosaceae) along with two known ursane-type triterpenoids, 2,3-O-isopropylidenyl-2α,3α,19α-trihydroxyurs-12-en-28-oic acid (3) and 1β-hydroxyeuscaphic acid (4). The chemical structures of 1 and 2 were determined to be 2,3-O-isopropylidene-1β,2β,3β,19α-tetrahydroxyurs-12-en-28-oic acid and 1,2-O-isopropylidene-1β,2α,3α,19α-tetrahydroxyurs-12-en-28-oic acid, respectively, based on spectroscopic data. Additionally, their cytotoxic activity towards HL-60 human leukaemia cells was evaluated. Among them, 3 demonstrated a clear cytotoxic activity with 72.8 μM of IC₅₀ value.     

Antimicrobial and antioxidant activities of a new benzamide from endophytic Streptomyces sp. YIM 67086

A new benzamide (1) and four known compounds (2–5) were isolated from endophytic Streptomyces YIM67086, and their structures were determined as 2-amino-3,4-dihydroxy-5-methoxybenzamide (1), 4-hydroxy-3-methoxybenzoic acid (2), phenylacetic acid (3), N-acetyltyramine (4) and p-hydroxytruxinic acid (5). Compound 5 was first found in the microorganism. The antimicrobial activities of compounds 1–5 and antioxidant activity of compound 1 were investigated.     

Studies on Pyrazine Derivatives,XLV: Synthesis,Reactions, and Tuberculostatic Activity of N-Methyl-N′-(pyrazine-2-carbonyl)-hydrazinecarbodithioic Acid Methyl Ester

Methyldithiocarbonyl derivative 2 of pyrazine-2-carboxylic acid N′-methyl-hydrazide 1 was synthesized by methylation of CS₂ adduct. Benzylamine caused the decomposition of compound 2 to pyrazine-2-carboxylic acid benzylamide 5 and 1,3-dibenzylthiourea 6. N-methyl-N′-(pyrazine-2-carbonyl)-hydrazinecarbodithioic acid methyl ester 2 were evidenced to cyclize to 3-methyl-5-pyrazin-2-yl-3H-[1, 3, 4]oxadiazole-2-thione 8 in the presence of triethylamine. In the reactions with secondary amines such as morpholine, pyrrolidine and phenylpiperazine pyrazinoyl derivatives (9–11) of thiosemicarbazide were obtained. Hydrazine, methylhydrazine, aminoalcohols, and N-alkylamino-substituted cyclic amines reacted with cyclization to 4-substituted 1,2,4-triazole-3-thiones 12, 13, and 18–22. Synthesized compounds exhibited low tuberculostatic activity in vitro (MIC 50–100 μg/mL).     

Two new diacetylene glycosides: bhutkesoside A and B from the roots of Ligusticopsis wallichiana

Two new diacetylene glycosides: bhutkesoside A (1) and B (2), along with 10 known compounds, i.e. falcarindiol (3), chlorogenic acid (4), 5-O-p-coumaroyl-quinic acid (5), 3,5-di-O-caffeoyl-quinic acid (6), 4-hydroxy-7-methoxy-phenylethanol (7), ferulic acid (8), dehydrodiconiferyl alcohol-4-O-β-d-glucopyranoside (9), 5,7-dihydroxy-2-methylchromone-7-O-rutinoside (10), schumanniofioside B (11) and marmesinin (12) were isolated from the roots of Ligusticopsis wallichiana (DC) Pimenov & Kljuykov (Apiaceae), commonly known as ‘Bhutkesh’ in Nepal. The structures were determined on the basis of spectroscopic data. Compounds 4 and 6 showed potent antioxidant activity on DPPH free radical scavenging assay.     

A new dihydrobenzofuran lignan and potential α-glucosidase inhibitory activity of isolated compounds from Mitrephora teysmannii

A new dihydrobenzofuran lignan, (2R,3S)-2-(3′,4′-dimethoxyphenyl)-5-(3-hydroxypropyl)-7-methoxy-2,3-dihydrobenzofuran-3-methyl acetate, named as mitredrusin (1), was isolated from the leaves of Mitrephora teysmannii (Annonaceae) together with 12 known compounds including a related dihydrobenzofuran lignan: (?)-3′,4-di-O-methylcedrusin (2), four polyacetylenic acids: 13(E)-octadecene-9,11-diynoic acid (3), 13(E),17-octadecadiene-9,11-diynoic acid (4), octadeca-9,11,13-triynoic acid (5) and octadeca-17-en-9,11,13-triynoic acid (6), five lignans: (?)-eudesmin (7), (?)-epieudesmin (8), (?)-phillygenin (9), magnone A (10) and forsythialan B (11) and two megastigmans: (3S,5R,6S,7E,9R)-7-megastigmene-3,6,9-triol (12) and annoionol A (13). The chemical structures of these compounds were established on the basis of their 1-D and 2-D NMR spectroscopic data. All compounds were evaluated for their α-glucosidase inhibitory activity. Among these isolates, polyacetylenic acids 3 and 4 showed more than 20-fold much higher activity compared with that of the antidiabetic drug acarbose.     

A new alkaloid from Portulaca oleracea L. and its antiacetylcholinesterase activity

A new alkaloid, (10E, 12E)-9-ureidooctadeca-10, 12-dienoic acid, named oleraurea (1) and 10 known compounds, p-hydroxybenzaldehyde (2), p-hydroxybenzoic acid (3), p-hydroxyacetophenone (4), benzamide (5), (E)-p-coumaramide (6), (E)-ferulamide (7), soyalkaloid A (8), β-carboline-3-carboxylic acid (9), 2, 3, 4, 9-tetrahydro-1H-pyrido [3, 4-b] indole-3-carboxylic acid (10), (1S, 3S)-1-methyl-1, 2, 3, 4-tetrahydro-β-carboline-3-carboxylic acid (11) were obtained from Portulaca oleracea L., in which, compounds 4, 5, 8–11 were isolated from the plant for the first time. The structure of the compound 1 was identified using spectroscopic methods including 1D and 2D NMR, HR-ESI-TOF-MS. The compounds 1, 5–11 presented anticholinesterase activities, but the P. oleracea extract (POE) presented very low anticholinesterase activity.     

Extraction of Co(II) and Ni(II) ammine cations from aqueous solutions into chloroform by highly lipophilic crown carboxylic acids

The proton-ionizable crown ethers, 2-[(sym-dibenzo-14-crown-4)oxy]-decanoic acid (1), 2-[sym-dibenzo-16-crown-5)oxy]decanoic acid (2), and 2-[sym-dibenzo-19-crown-6)oxy]decanoic acid (3) efficiently extract Co(II) and Ni(II) ammine cations from highly alkaline aqueous solutions (pH>10) into chloroform. For extractions of the individual metal species,2 is more efficient than1 or3. In competitive extraction systems, good selectivity for Co(II) ammine cations over Ni(II) ammine cations is observed.     

Synthesis,crystal structure,thermal stability,and photoluminescence of a 3-D silver(I) network with twofold interpenetrated dia-f topology

A silver(I) coordination polymer with mixed 3,3′,5,5′-tetramethyl-4,4′-bipyrazole (bpz) and maleic acid, [Ag₂(bpz)₃(fum)]_n (1, H₂fum = fumaric acid), was synthesized under hydrothermal condition by in situ isomerization of maleic acid to fumaric acid and characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction, TGA, and single-crystal X-ray diffraction. The maleic acid in situ isomerizes to fumaric acid and participates in the formation of 1. Topologically, the structure of 1 features a rare 3-connected twofold interpenetrated dia-f net with a point symbol of {4.14²}. Compound 1 exhibits photoluminescence in the solid state with an emission maximum at 470 nm upon excitation at 365 nm at room temperature, which is attributed to intraligand or/and interligand π → π* transition.     

Über Reaktionen mit Betain,XIV Darstellung von Trifluoracetyl-methylid-trifluoracetaten aus Betainen

The reaction of trimethylammonium acetic acid betaine (1) with trifluoroaceticanhydride (TFA) yielding trifluoroacetyl-N-methylide can be extended to triethylammonium acetic acid betaine (2), 2-pyridiniumpropionic acid betaine (9) andN,N-dimethyl-piperidinium-2-carboxylate betaine (14). Trigonelline and 3-pyridiniumpropionic acid betaine (11), however, do not react in this way. It follows that the formation of such ylides is only possible if the methylene or methine group of the betaines are flanked by ammonium and carboxylate group.

Herrn emer. o. Univ.-Prof. Dr. techn. Dr. hc.Otto Kratky, Institut für Feinstrukturforschung der Österr. Akademie der Wissenschaften und Forschungszentrum Graz, zur Vollendung des 80. Lebensjahres gewidmet.     

ORGANISCHE PHOSPHORVERBINDUNGEN 85.1 HERSTELLUNG,EIGENSCHAFTEN UND BIOLOGISCHE WIRKUNG VON N-AMINOGLYPHOSATE UND AZAGLYPHOSATE

Abstract

The synthesis and the chemical, physical and spectral properties of N-aminoglyphosate ethylester (hydrazino-N′-carbethoxymethyl-N′-methylphosphonic acid) 4a, H₂OPCH₂N(NH₂)CH₂CO₂C₂H₅, of hydrazino-N′-carbethoxymethyl-N′-methyl-P-methylphosphinic acid 4b, CH₃(HO₂)PCH₂N(NH₂)-CH₂CO₂C₂H₅, and of azaglyphosate ethylester (hydrazino-N-carbethoxymethyl-N-methyl-phosphonic acid 9, H₂O₃PCH₂NHNHCH₂CO₂C₂H₅, are described. 4a, 9 and 10 exhibit plant growth regulating properties.     

Synthesis of Derivatives of ω-Isocyanato-α-methylamino, ω-Ureido-α-methylamino, and Nα-Methyl-α, ω-diamino Acids

 Homochiral N^α-methyl-2,3-diaminopropionic and N^α-methyl-2,4-diaminobutyric acid derivatives 8a,b were obtained via a stereoconservative four-step synthesis starting from hexafluoroacetone protected L-aspartic and L-glutamic acid 2a,b, respectively. Hexafluoroacetone protected ω-isocyanato-α-methylamino acids 4a,b– the key intermediates of the synthesis – are versatile building blocks for amino acid and peptide modification and promising candidates for combinatorial chemistry. Upon reaction with alcohols, compounds 4 give activated N ^ω-urethane protected ω-amino-α-methylamino acid derivatives 5–7; upon reaction with amines, ω-ureido-α-methylamino acid derivatives 10–12 and 3-methylamino-pyrrolidin-2-ones 13 are available.     

A new ent-kaurane diterpenoid from Ixora amplexicaulis

A new ent-kaurane diterpenoid, 6α,16α-dihyroxy-ent-kaurane (1), was isolated from the stems of Ixora amplexicaulis, together with (24R)-6β-hydroxy-24-ethyl-cholest-4-en-3-one (2), 7β-hydroxysitosterol (3), maslinic acid (4), 3,3′-bis(3,4-dihydro-4-hydroxy-6-methoxy-2H-1-benzopyran) (5) and protocatechuric acid (6). Their structures were established by extensive spectroscopic analysis, including 2D NMR techniques. Compounds 2–5 were isolated from the genus Ixora for the first time and 6 obtained originally from I. amplexicaulis.