Macrocarpamin,ein neues Bisindolalkaloid aus Alstonia macrophylla WALL. 167. Mittelung über organische Naturstoffe

Macrocarpamine, a new bisindole alkaloid from Alstonia macrophylla WALL . A new bisindole alkaloid give the name (?)-macrocarpamine ( 3 ) was isolated from the bark of Alstonia macrophylla WALL . Under pyrolytic conditions 3 is cleaved into the two known bases (+)-pleiocarpamine ( 2 ) and (?)-anhydro macrosalhin-methin ( 5 ) (Scheme 1). The structure of 3 (including relative configuration) was deduced on the basis of chemical evidence and from its UV.-, IR.-, NMR.- and mass spectroscopic data.     

Über Alkaloide aus Laurelia novae-zelandiae A. CUNN. 5. Mitteilung über natürliche und synthetische Isochinolinderivate

From an extract of Laurelia novae-zelandiae A. CUNN . the aporphine alkaloids (?)-pukateine (I), (?)-pukateine methyl ether (II), (?)-roemerine (IV), (?)-mecambroline (V), (+)-boldine (VII), (+)-isoboldine (VIII), (+)-laurolitsine (IX), and the proaporphine alkaloid (+)-stepharine (X) were isolated. Compounds II and V were up to now not described as natural alkaloids. These and the alkaloids IV, VII, VIII, IX and X are new for L. novae-zelandiae.     

Die Alkaloide aus Hedranthera barteri (Hook. f.) Pichon. 139. Mitteilung über Alkaloide

From the root bark of the apocynacea Hedranthera barteri (Hook. f.) Pichon were isolated the known indole alkaloids vobtusine ( 1 ), voacamine ( 2 ), callichiline ( 3 ), voacangine ( 4 ) and conoflorine ( 5 ), as well as the unknown plant bases amataine, goziline and owerreine, and also beninine and 1, 2-dehydrobeninine. The structures of the two last mentioned alkaloids were shown in an earlier publication to be 6 and 7 , respectively. Amataine, goziline and owerreine are bis-indole alkaloids, which on the basis of their chemical and spectroscopic (especially mass spectroscopic) properties have been assigned the structures 8 , 9 and 10 , respectively.     

Die Struktur des Bisindolalkaloides Amatain ( = Grandifolin,Subsessilin)

The structure of the bisindole alkaloid amataine (= grandifoline, subsessiline) Amataine ( 1 ) was isolated from the roots of Hedranthera barteri (HOOK . F .) PICHON (Apocynaceae). In comparison to the alkaloid vobtusine ( 5 ), which was isolated from the same plant, 1 contains two hydrogen atoms less. By reduction of 1 with H₂/PtO₂ or with NaBH₄ dihydromataine ( = isovobtusine, 13 ) was formed which is isomeric to 5 . Acid catalysed water addition to 1 afforded hydratoamataine ( 15 ), which was reduced to 5 with NaBH₄. Thermolysis of 15 gave 1 . The difference between the two isomeric bases 5 and 13 has to be attributed to a different configuration at the spirocenter C(7). In contrast to 5 amataine ( 1 ) contains an ether bridge instead of a hydroxy group; this bridge is located between C (2′) and C (8).     

Indolalkaloids of Pleiocarpa talbotii Wernham. 145. Alkaloids

Besides talbotine ( 1 ) three new indole alkaloids, talpinine ( 2 ), talcarpine ( 3 ) and 16-epi-affinine ( 4 ) were isolated from the stem bark of Pleiocarpa talbotii Wernham. The structure of 2 was deduced by chemical degradation and by analyses of the spectra of the alkaloid and its derivatives. One of these derivatives is identical with talcarpine ( 3 ). The structures 2 and 3 are similar to that of macroline ( 14 ), a splitting product of the bisindole alkaloid villalstonine from Alstonia species. 16-epi-Affinine ( 4 ) was chemically correlated with the known alkaloid vobasine ( 19 ). Talpinine ( 2 ) and 16-epi-affinine ( 4 ) were also isolated from the root bark of Pleiocarpa talbotii.     

Alkaloid Production in Catharanthus roseus Cell Cultures. VII.. Effect of parameter changes and catabolism studies on cell line PRL No. 953

Catharanthus roseus cells suspended in production medium showed the presence of four Aspidosperma-type alkaloids, however, no vindoline. Cells grown in media with the pH adjusted to 7.0 produced 3.3 mg total alkaloids/g dry weight. At pH 5.0, 1.7 mg of alkaloid/g dry weight was produced. (S)-Adenosyl-methionine did not stimulate the production of vindoline. When added to cell suspensions for 21 days, vindoline and catharanthine were degraded to non-alkaloidal substances, not dimerized to bisindole alkaloids.     

Über das Alkaloid Lonicerin aus Callichilia barteri. 137. Mitteilung über Alkaloide

The alkaloid lonicerine was isolated from Callichilia barteri (Apocynaceae). By chemical and spectroscopic evidence it could be shown to be 16-epi-aspidodasycarpine ( 1 ).     

Isolierung von (−)-Dunnion aus Calceolaria integrifolia MURR. (Scrophulariaceae)

Isolation of (?)-dunnione from the leaves of Calceolaria integrifolia, MURR . (fam. Scrophulariaceae) From the leaves of Calceolaria integrifolia, a plant often used in horticulture. partially racemic (?)-dunnione (1) has been isolated. This seems to be the first record of its occurrence outside the family Gesneriaceae, where it previously has been found in two species as the (+)-enantiomer.     

Über die Struktur der makrocyclischen Spermidin-Alkaloide Oncinotin,Neooncinotin und Isooncinotin. 151. Mitteilung über Alkaloide

Three spermidine alkaloids – oncinotine ( 1 ), neooncinotine ( 3 ), and isooncinotine ( 2 ) – have been isolated from the stem bark of Oncinotis nitida BENTH . (Scheme 1); 1 and 3 are so far an unseparable mixture. However, by treatment of this mixture with K-t-butoxide, neooncinotine is completely converted into isooncinotine, and oncinotine, the main alkaloid, is obtained in pure form. The structural assigment of these alkaloids is based on chemical and spectral evidence. Thus oncinotine ( 1 ) has been degraded via 24 (Scheme 4) and 32 to the putrescine derivative 35 and the piperidine derivative 34 (Scheme 5). Similarly neooncinotine ( 3 ) and isooncinotine ( 2 ), have given 34 along with the 1, 3-diaminopropane derivative 36 (Scheme 5). The major decomposition pathways of 24 , 35 and 36 in the mass spectra are described in Schemes 8, 6 and 7 respectively. The absolute configuration of 1 , 2 and 3 is derived by chiroptical correlations with (R)-(?)-N-methylconiine ( 38 ).     

Alkaloids from Bulbocodium vernum L. Content material of Liliaceae-Wurmbaeoidaea

From whole plants of Bulbocodium vernum L. the flavone luteoline (I) and the alkaloids colchicine (II), N-formyl-N-deacetylcolchicine (III), 3-demethylcolchicine (V), (+)-bulbocodine (IX) and (?)-kreysigine (XI) were isolated in crystals. The presence of 2-demethylcolchicine (IV), ß- (VII) and γ-lumicolchicine (VIII), demecolcine (VI) and five not identified alkaloids was demonstrated by thin-layer chromatography. On the basis of ultraviolet, infrared and mass spectra, PMR.-analysis (Overhauser effect), and circular dichroism, the (6a-R, 8a-S)homo-proaporphine structure IX, with one methoxy group at C-2, has been assigned to (+)-bulbocodine. The (6a-R)-structure (XI) was deduced for (?)-kreysigine by comparing its optical rotation and circular dichroism which the values of (?)-multifloramine (X), the structure of which is known.     

Structure d'alcaloïdes indoliques doubles d'un type nouveau

The Structure of bis-indoline alkaloids of a novel type The structure of folicangine 4 , a bis-indoline alkaloid from the leaves of Voacanga africana, is obtained by correlation with voafolidine 3a and isovoafolidine 3b . It requires an ether bridge between the two parts of the molecule, as in subsessiline (amataine 5a ). Subsessiline-lactone, from the leaves of Voacanga thouarsii has structure 5b proved by correlation with 5a . The CD. curves of double-indole alkaloids of vobtusine type are given (Table 3).     

Die Konstitution des Alkaloides Juliprosopin aus Prosopisjuliflora A. Dc. 176. Mitteilung über organische Naturstoffe

The Structure of the Alkaloid Juliprosopine from Prosopis juliflora A. Dc. A new alkaloid, juliprosopine, has been isolated from Prosopis juliflora A. Dc. (Leguminosae), for which structure 1 is proposed. The piperidine moiety could be elucidated on the basis of spectroscopic data (MS., ¹H-NMR., ¹³C-NMR.) of juliprosopine and the derivatives 2–4 . The central hexahydroindolizine part and its substitution pattern has been determined mainly on the bases of the Hofmann-degradation product 11 , which yielded the hydrogenation products 13 and 14 . By ozonolysis 11 was converted to 16 and 18 . It is proposed that juliprosopine was built up in nature by two ‘monomeric’ Prosopis alkaloids and one dihydropyrrol unit.     

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.     

Berberis alkaloids XXXIX. New alkaloids fromB. densiflora

The alkaloid composition of the leaves ofBerberis densiflora has been studied. Berberine, -allocryptopine. oxyacanthine, glaucine, thalicmidine, isocorydine, O-methylcorypalline and the new bases densinine and densiberine have been isolated. The structures of the new alkaloids have been established by a study of spectral characteristics and chemical transformations. This is the first time that any of the known alkaloids, apart from berberine, have been isolated from a plant of this pecies and it is the first time that -allocryptopine and O-methylcorypalline have been isolated from theBerberis genus.     

Two novel indole alkaloids, Kopsiyunnanines A and B, from a Yunnan Kopsia

Two novel indole alkaloids having unusual skeletons were isolated from the aerial part of Yunnan Kopsia arborea. Kopsiyunnanine A (1) is a new class of bisindole alkaloid composed of vallesiachotamine (modified Corynanthe-type) and Aspidospermatan-type alkaloids. Kopsiyunnanine B (2) is a new Corynanthe-type oxindole alkaloid rearranged by D ring rotation.     

14‐Membered Cyclopeptides from Paliurus ramosissimus and P. hemsleyanus

Six 14‐membered cyclopeptide alkaloids, i.e., ramosines A–C, mucronine J, and lotusines A and D, were isolated from the roots of Paliurus ramosissimus, and an additional four, hemsines A–D, from the roots of P. hemsleyanus. Among these, ramosines A–C ( 1, 5 , and 6 , resp.) and hemsines A and B ( 7 and 8 , resp.) are new bases of the amphibine‐B type, and hemsines C and D ( 9 and 10 , resp.) are new integerrine‐type alkaloids. Additionally, ramosine C ( 6 ) represents the first 14‐membered cyclopeptide alkaloid possessing a substitution (? OH) at C(13′). Their structural elucidations were based on spectral analysis and molecular‐modeling studies. Pronounced solvent effects in the ¹H‐ and ¹³C‐NMR spectra of these two types of alkaloids were observed.     

Structure and absolute stereochemistry of 19-epi-(+)-echitoveniline : A new indole alkaloid of the leaves of Alstonia venenata r.br.

19-Epi-(+)-echitoveniline, a new indole alkaloid of the leaves ofAlstonia venenata R.Br., has been shown to possess the structure and absolute stereochemistry represented by 5b on the basis of spectral and chemical evidence. A mechanistic rationale for the dependence of the mode of LAH reduction of the δ-lactone 11 on its configuration at C-19 has been offered. The influence of the C-19 configuration on the chemical shift values of the C-16 carbomethoxy protons in the 19-aroyloxy-(+)-and (?)-vincadifformine alkaloids has been discussed.     

Biologically active indole and bisindole alkaloids from Tabernaemontana divaricata

The ethanol extract of the leaves of Tabernaemontana divaricata (double flower variety) provided a total of 23 alkaloids, including the new aspidosperma alkaloids, taberhanine, voafinine, N-methylvoafinine, voafinidine, voalenine and the new bisindole alkaloid, conophyllinine in addition to the previously known, biologically active bisindole, conophylline and its congener, conofoline. The structures of the new alkaloids were established by spectroscopic methods. The preparation and characterization of the corresponding quinones of the biologically active bisindoles are also described in relation to a structure-activity study of these compounds with respect to their action in stimulating insulin expression.     

Biosynthesis of the Indole Alkaloids. Cell-free Systems from Catharanthus roseus Plants

Cell-free systems from Catharanthus roseus plants are utilized for various studies relating to the biosynthesis of indole alkaloids. Tryptamine ( 5 ) and secologanin ( 6 ), two fundamental building units, are shown to be incorporated into the alkaloid vindoline ( 7 ). In another study, catharanthine ( 18 ) and vindoline ( 7 ) are utilized by this enzyme system and coupled to the important bisindole biointermediate 3′,4′-anhydrovinblastine

1 The previously [20] used name for 17 , 3′, 4′-dehydrovinblastine, is incorrect.

( 17 ). The latter substance is, in turn, incorporated and converted to the natural alkaloids leurosine ( 8 ), Catharine ( 9 ) and vinblastine ( 10 ), thereby providing information about the biosynthesis of these complex molecules. High pressure liquid chromatography assay of the enzymic mixture sheds light on the enzymes involved in the coupling of 18 and 7 .     

Macrocyclische Spermidinalkaloide aus Pleurostylia africana LOES. 9. Mitteilung über Celastraceen-Inhaltsstoffe

Macrocyclic Spermidine Alcaloids from Pleurostylia africana LOES . The structure of pleurostyline, a new macrocyclic spermidine alkaloid from Pleurostylia africana (Celastraceae), has been elucidated mainly by ¹H- and ¹³C-NMR.-spectroscopy. Pleurostyline represents a new structure type in which spermidine is incorporated in a 13-membered lactam ring to which an additional cinnamoyl residue is fused to yield a 7-membered ring. The same plant contains also the spermidine alkaloids celacinnine and cellallocinnine of which ¹³C- and high field ¹H-NMR.-measurements have been carried out for the first time. Both alkaloids are interconvertible by UV.-irradiation. In addition the existence of rotational isomerism of one amide group of these alkaloids has been demonstrated by NMR.-spectroscopy.