Two new alkaloids from cigarette smoke condensate

Chemical constituents of MeOH extracts of cigarette smoke were studied. Two new alkaloids, named cigatin A (1), 2-(Pyridine-3-yloxy)-benzene-1',4'-diol and B (2), 2-(4-Methyl-pyridin-3-yloxy)-benzene-1',4'-diol, were isolated from a mainstream condensate of cigarette together with seven known alkaloids. Their structures were determined on the basis of spectral data and chemical methods.     

Chemical constituents of Talauma arcabucoana (Magnoliaceae): their brine shrimp lethality and antimicrobial activity

A new aporphine alkaloid, (-)-arcabucoine [(6aR)-N-formyl-1,2-methylenedioxy-9,10-dimethoxy-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinoline] 1 was isolated from the leaves of Talauma arcabucoana (Magnoliaceae), along with the known compounds (-)-erythro-saccharinic acid lactone 2 and (-)-shikimic acid 3. Furthermore, the known aporphine alkaloids (-)-dicentrine 4, (-)-nordicentrine 5 and dicentrinone 6 were isolated from the stem bark. The alkaloids 4 and 5 were found to be the most active compounds in a brine shrimp lethality assay. In addition, alkaloids 1, 4 and 5 showed moderate growth inhibition against Staphylococcus aureus and Candida albicans.     

Subincanadines A-C,novel quaternary indole alkaloids from Aspidosperma subincanum

Three novel quaternary indole alkaloids with an unprecedented 1-azoniatricyclo[4.3.3.0(1,5)]undecane moiety, subincanadines A-C (1-3), as well as two new indole alkaloids with a 1-azabicyclo[5.2.2]undecane moiety, subincanadines D (4) and E (5), and a new indole alkaloid with a 1-azabicyclo[4.3.1]decane moiety, subincanadine F (6), have been isolated from the barks of Aspidosperma subincanum Mart, and the structures of 1-6 and the stereochemistry of 1-3 were elucidated by spectroscopic data and chemical means.     

2-Phenyl-4-quinolinone Alkaloids from Casimiroa edulis Llave et Lex (Rutaceae)

 Three new 4-quinolinone alkaloids (5,6-dimethoxy-2-(3-methoxyphenyl)-1H-quinolin-4-one, 5,6-dimethoxy-2-(3,4-dimethoxyphenyl)-1H-quinolin-4-one, 5,6-dimethoxy-2-(2,5,6-trimethoxyphenyl)-1H-quinolin-4-one) were isolated from the leaves of Casimiroa edulis Llave et Lex (Rutaceae) cultivated in Egypt. Their structures were determined by UV/Vis, IR, ¹H and ¹³C NMR, and EI mass spectroscopy. The alkaloids were also detected in the kernels of the seeds.     

New tricyclic alkaloids, cassiarins G, H, J, and K from leaves of Cassia siamea

Four new alkaloids, cassiarins G, H, J, and K (1-4) which showed moderate antiplasmodial activity against Plasmodium falciparum 3D7, were isolated from the leaves of Cassia siamea (Leguminosae) and the structures of 1-4 were elucidated by 1D- and 2D-NMR analysis and X-ray crystallographic analysis.     

Two New Anti-Tobacco Mosaic Virus Quinoline Alkaloids from the Stems of Nicotiana tabacum

Chemistry of Natural Compounds - Two new quinoline alkaloids, 4-acetyl-7-isopropyl-6-methylquinolin-2(1H)-one (1) and 4-acetyl-7-isopropyl-5-methylquinolin-2(1H)-one (2), were isolated from the...     

Cytotoxic metabolites from the soil-derived fungus Exophiala pisciphila

A new polyketide compound 1 and a new naturally occurring chromone derivative 2, along with two known indole alkaloids 3-4 were characterized from the ethyl acetate extract of a soil-derived fungal strain, Exophiala pisciphila PHF-9. The structures of compounds 1-4 were established by detailed spectroscopic analysis and comparison with literature data. The absolute configuration of 1 was determined by a modified Mosher's method. Compound 1 exhibited moderate cytotoxicity against A-549, Hela, PANC-28 and BEL-7402 cell lines.     

New pseudan (2-alkyl-4(1H)-quinolinone) alkaloids from Boronia ternata var. elongata and Boronia alulata (Rutaceae)

The aerial parts of Boronia ternata var. elongata from western Australia has yielded three new 2-acyl-4(1H)-quinolinone alkaloids, characterised as 2-n-pentyl-4(1H)-quinolinone, 1-methyl-2-n-pentyl-4(1H)-quinolinone and 1-methyl-2-(1 xi-methyl)-propyl-4(1H)-quinolinone, as well as known alkaloids of this class and a furoquinoline alkaloid. Boronia alulata, from northeast Queensland, also yielded 2-n-pentyl-4(1H)-quinolinone together with the known 2-n-propyl-4(1H)-quinolinone. Both species are assigned to Boronia section Valvatae which, alone among the sections of Boronia, appears to be characterised by the presence of alkaloids.     

Nakijinamines C-E, new heteroaromatic alkaloids from the sponge Suberites species

Three new heteroaromatic alkaloids, nakijinamines C-E (1-3), which are a hybrid of the aaptamine-type and bromoindole alkaloids possessing a taurine- or histidine-derived residue, have been isolated from an Okinawan marine sponge Suberites species. The structures of 1-3 were elucidated on the basis of spectroscopic data and chemical conversions. Nakijinamines C (1) and E (3) are the first natural products possessing a 1H-oxazolo[4',5':4,5]benzo[1,2,3-de][1,6]naphthyridine ring system.     

2-Phenyl-4-quinolinone Alkaloids from Casimiroa edulis Llave et Lex (Rutaceae)

Summary.  Three new 4-quinolinone alkaloids (5,6-dimethoxy-2-(3-methoxyphenyl)-1H-quinolin-4-one, 5,6-dimethoxy-2-(3,4-dimethoxyphenyl)-1H-quinolin-4-one, 5,6-dimethoxy-2-(2,5,6-trimethoxyphenyl)-1H-quinolin-4-one) were isolated from the leaves of Casimiroa edulis Llave et Lex (Rutaceae) cultivated in Egypt. Their structures were determined by UV/Vis, IR, ¹H and ¹³C NMR, and EI mass spectroscopy. The alkaloids were also detected in the kernels of the seeds. Received May 28, 2001. Accepted (revised) July 24, 2001     

New proaporphines from the bark of Phoebe scortechinii

The phytochemical study of the bark of Malaysian Phoebe scortechinii (Lauraceae) has resulted in the isolation and identification of two new proaporphine alkaloids; (+)-scortechiniine A (1) and (+)-scortechiniine B (2) together with two known proaporphines; (-)-hexahydromecambrine A (3), (-)-norhexahydromecambrine A (4), and one aporphine; norboldine (5). Structural elucidations of these alkaloids were performed using spectroscopic methods especially 1D and 2D (1)H and (13)C NMR.     

Three new C_(20)-diterpenoid alkaloids from Delphinium anthriscifolium var.savatieri

Three new C20-diterpenoid alkaloids, designated as anthriscifolmines A-C (1-3), together with two known alkaloids denudatine and delgramine, were isolated from the whole herb of Delphinium anthriscifolium var. savatieri. The structures of these new alkaloids were elucidated on the basis of spectral data.     

New bisindole alkaloids isolated from Myxomycetes Arcyria cinerea and Lycogala epidendrum

Two new bisindole alkaloids, named cinereapyrrole A (1) and B (2), were isolated from wild fruit bodies of Arcyria cinerea and three new bisindole alkaloids (3-5) were isolated from wild fruit bodies of Lycogala epidendrum. Seven known bisindoles (6-12) were concomitantly obtained from them. The structures of the new compounds were elucidated by spectral data. Among these bisindole alkaloids, compound 12 showed cytotoxicity against cultured tumor cell lines.     

New alkaloids from <Emphasis Type="Italic">Casimiroa edulis</Emphasis> fruits and their pharmacological activity

The extract of Casimiroa edulis was investigated for antihypertensive activity. The ethanol and total alkaloids (in chloroform) extracts were found to have antihypertensive properties at doses of 500 and 200 mg/kg, respectively. Four quinolinone alkaloids were isolated and identified as: 2-(2′-hydroxy-4′-methoxyphenyl)-5,8-dimethoxy-3-propyl-1H-quinolin-4-one (1), 5,8-dimethoxy-2-(3′-methoxyphenyl)-3-propyl-1H-quinolin-4-one (2), 5,8-dimethoxy-2-(3′,4′-dimethoxyphenyl)-3-propyl-1H-quinolin-4-one (3), and 5,6-dimethoxy-2-(2′,5′,6′-trimethoxyphenyl)-1H-quinolin-4-one (4). Interestingly, compounds 1, 2, and 3 were found to be new alkaloids. The four isolated alkaloids showed antihypertensive activity at doses of 50, 100, 200, and 300 mg/kg, respectively. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 473–476, September–October, 2007.     

Two New Furo[3,2-c]Quinolines from the Stems of Nicotiana tabacum and Their Anti-Tobacco Mosaic Virus Activity

Chemistry of Natural Compounds - Two new (1 and 2), together with two known (3 and 4), quinoline alkaloids were isolated from the stems of Nicotiana tabacum. Their structures were elucidated using...     

New C(19)-diterpenoid alkaloids from the roots of Delphinium potaninii var. jiufengshanense

From the roots of Delphinium potaninii var. jiufengshanense, two new lycoctonine-type C(19)-diterpenoid alkaloids called jiufengdine (1) and jiufengtine (4) have been isolated. The structures of the new alkaloids (1, 4) were established by 1D and 2D NMR spectra.     

New steroidal alkaloids from Solanum hypomalacophyllum

Two new steroidal alkaloids (1-2) have been isolated from the leaves and roots of Solanum hypomalacophyllum Bitter, respectively. Their structures have been elucidated as deacetoxysolaphyllidine-3-O-beta-D-glucopyranoside (1) and 4-keto-5,6-dihydro-(20S)-verazine (2). Furthermore, two known steroidal alkaloids, 20R-verazine and 20S-verazine, and the common secondary metabolites oleanolic acid and beta-sitosterol were isolated from the roots, whereas deacetoxysolaphyllidine was obtained from the leaves.     

Die Alkaloide von Gabunia eglandulosa STAPF 155. Mitteilung über Alkaloide

From the root bark of the Apocynaceae Gabunia eglandulosa STAPE seven indole alkaloids were isolated. Besides the known indole alkaloids (?)-isovoacangine ( 1 ), (?)-coronaridine ( 2 ), voacamine ( 3 ), vobasine ( 4 ), and perivine ( 5 ), two new bases (?)-19-hydroxy-isovoacangine ( 6 ) and 19-hydroxy-coronaridine ( 15 ) were isolated. Compound 6 was obtained by oxidation of isovoacangine with iodine. Similar oxidation reactions with voacangine ( 12 ) were studied.     

Bistellettazines A-C and bistellettazole A: new terpenyl-pyrrolizidine and terpenyl-imidazole alkaloids from a southern Australian marine sponge, Stelletta sp

Four new alkaloids have been isolated during chemical investigations into a southern Australian marine sponge, Stelletta sp. Detailed spectroscopic analysis, supported by chemical degradation and partial synthesis, permitted structure elucidation of bistellettazines A-C ( 1- 3), the first reported examples of terpenyl-pyrrolizidine conjugates, and bistellettazole A ( 4), a unique cyclic terpenyl-imidazole conjugate. The alkaloids 1- 4 feature unprecedented carbon skeletons that are proposed to share a common convergent biosynthetic origin, arising via the biogenic equivalent of a Diels-Alder addition between two hypothetical polyenyl norsesquiterpene precursors.     

直缘乌头中新的C19—二萜生物碱的结构研究

从直缘乌头（Aconitum transsectum Diels.）根中分离得到4个新的乌头碱型 C_(19)-二萜生物碱。由光谱法（IR, ~1H NMR, ~(13)C NMR, 2D-NMR, MS）确定其 结构为:8-O-乙基滇乌碱（8-O-ethylyunaconitine） (1)、去氮乙基查斯曼宁（N- deethyl chasmanine）(2)、直缘乌碱丁（transconitine D）(3)和直缘乌碱戊（ transconitine E）(4)。