New organic bases from amazonian Banisteriopsis caapi

Three new bases were isolated from Banisteriopsis caapi; they are harmine N-oxide, harmic acid methyl ester (methyl 7-methoxy-β-carboline 1-carboxylate) and harmalinic acid (7-methoxy-3,4-dihydro-β-carboline 1-carboxylic acid).     

New alkaloids from Strychnos icaja

The alkaloids of Strychnos icaja (Loganiaceae) have been studied. An extract from Zaire leaf material yielded nine alkaloids, comprising novacine, the new base 21,22-α-epoxy-4,14-dihydroxy-3-methoxy-N-methyl-sec.-pseudostrychnine, and seven others of known structure previously obtained from the plant. Cameroun leaf material gave five alkaloids, of which one, 21,22-α-epoxy-3,4-dimethoxy-N-methyl-sec.-pseudostrychnine, is new. Fruits from Gabon afforded eight alkaloids; two of them are new and are formulated as 21,22-α-epoxy-4-methoxy-N-methyl-sec.-pseudostrychnine and the corresponding 14-hydroxy derivative.     

Three new alkaloids from Buxus papillosa

Three new steroidal alkaloids have been obtained from Buxus papillosa Schneider. These are (?)-cyclobuxupaline-C (IV)(+)-cyclopapilosine-D (VII) and (+)-buxamine-C (IX). A known alkaloid also present is desoxy-16-buxidienine (X).     

Tropane alkaloids from Anthocercis and Anthotroche

In addition to known tropane alkaloids, 3α-iso-butyryloxytropan-6β-ol and 3α-n-butyryloxytropane have been characterized as respective components of the aerial parts of two subspecies of Anthocercis albicans. Aponoratropine, not previously recorded as a natural product, has been detected in the leaves of Anthotroche myoporoides and A. walcottii; similarly aponorhyoscine is indicated as a component of the roots of a subspecies of Anthocercis genistoides.     

Pyrrolizidine alkaloids from Senecio cacaliaster

Four pyrrolizidine alkaloids have been isolated from Senecio cacaliaster and their structures analysed by spectroscopic methods (IR, mass, ¹H, ¹³CNMR). One of them is new and the name sencalenine (3) is proposed. Alkaloids O⁷-senecioylretronecine (1) and 7-senecioyl-9-sarracinylretronecine (2) have recently been identified elsewhere. The fourth is bulgarsenine (4) which was isolated from a Senecio species before.     

Quaternary alkaloids of Thalictrum foliolosum

The isolation and identification of eleven alkaloids from the quaternary alkaloid fraction of a root extract of Thalictrum foliolosum are described     

New peptide alkaloids from Hovenia dulcis and H. tomentella

From the root bark of Hovenia dulcis Thunb. and H. tommentella (Makino) Nakai (Rhamnaceae), three peptide alkaloids, frangulanine, hovenins-A and -B have been isolated. Hovenin-A has been shown to be des-N-methylfrangulanine (II).     

Adlumidiceine and adlumiceine: New alkaloids of narceine type

The structures of new alkaloids of narceine type, adlumidiceine (II), adlumiceine (III), and enol lactone of adlumidiceine (IV), isolated from Papaver rhoeas L. and Corydalis sempervirens (L.) Pers. (Papaveraceae), were determined by PMR, MS and IR spectra.     

Four new diterpenoid alkaloids from Delphiniumpentagynum

Four new diterpenoid alkaloids, dihydrogadesine, 14-acetyldihydrogadesine, pentagynine and dihydropentagynine, were isolated and identified in Delphinium pentagynum.     

Leaf alkaloids of Rauwolfia volkensii

Thirteen alkaloids were isolated and identified from the leaves of Rauwolfia volkensii. The alkaloids included E-seco heteroyohimbine, heteroyohimbine, sarpagan, dihydroindole, pleiocarpamine, picrinine and akuammicine types together with peraksine.     

Two new diterpene-based alkaloids from Icacina guesfeldtii

From Icacina guesfeldtii (leaves and roots), two new diterpene-based alkaloids have been isolated and identified as icaceine (2) and De-N-methylicaceine (3). Icacine (1) occurred both in the leaves and roots. Structure determination was performed by spectroscopic and chemical methods. As icacine (1), these two bases are the first alkaloids with a pimarane skeleton isolated from plants.     

Peptide alkaloids of Scutia buxifolia

Two new components, the peptide alkaloid scutianine D and scutianene C have been isolated from Scutia buxifolia and their structures elucidated. The configuration of some of the asymmetric centers of scutianine A has been determined by gas chromatography.     

Distribution of alkaloids in Anthocercis littorea and A. viscosa

The distribution of tropane alkaloids in organs of Anthocercis littorea and A. viscosa is reported. The following alkaloids have been isolated: atropine (hyoscyamine), apoatropine, noratropine (norhyoscyamine), littorine, hyoscine, norhyoscine, meteloidine, 3α, 6β-ditigloyloxytropan-7β-ol, 6β-tigloyloxytropan-3α-ol, 3α-tigloyloxytropane, tigloidine, tropine, ψ-tropine, (?)-tropan-3α-6β-diol, cuscohygrine and unknown bases.     

New indolopyridoquinazoline alkaloids from Euxylophora paraënsis

Two new indolopyridoquinazoline alkaloids euxylophoricine C (V) and euxylophorine B (VI), were isolated from the bark of Euxylophora paraënsis Hub. Their structures were elucidated on the basis of spectroscopic as well as chemical properties and confirmed by synthesis.     

Pregnane alkaloids from Pachysandra axillaris

Nine new pregnane alkaloids, pachysamines J-R (1-9), together with seven known ones, were isolated from Pachysandra axillaris. The chemical structures of the new alkaloids were elucidated by spectroscopic methods. All the compounds were evaluated for their inhibitory activities against HL-60, SMMC-7721, A-549, SK-BR-3, and PANC-1 cell lines. Compound 15 possessed moderate activities against A-549, SK-BR-3, and PANC-1 cells, with the IC₅₀ values of 11.17, 4.17, and 10.76 μM, respectively. Besides, compound 11 showed cytotoxicities against A-549 cell, with the IC₅₀ values as 24.94 μM.     

Dehydroisostrychnobiline,matopensine and other alkaloids from Strychnos kasengaensis

Eighteen alkaloids have been identified in the root bark, stem bark and leaves of Strychnos kasengaensis from Zaire, They are isoretulinal, retuline, desacetyl isoretuline, desacetyl retuline, dehydroisostrychnobiline, matopensine and its mono-N-oxide, nordihydrotoxiferine, isoretuline, N(1)-desacetyl 18-acetoxyisoretuline, Wieland-Gumlich aldehyde and diol, desacetyl isoretulinal, O-acetyl retuline, 16R-isositsirikine, O-acetyl isoretuline, 11-methoxy retuline and 11-methoxy isoretuline.     

New sesquiterpenoid alkaloids from Euonymus europea

Two new minor alkaloids from seeds of Euonymus europea L. have been characterised as 2-deacetylevonine and 2,5-bisdeacetylevonine by NMR. A selective one-step 5-deacetylation-bromobenzylation reaction of evonine is reported.     

Additional alkaloids from Laurelia philippiana and L. novae-zelandiae

Asimilobine, anonaine, noreorydine, nornantenine, (+)-reticuline and the new alkaloid, 4-hydroxyanonaine, were isolated from Laurelia philippiana bark. The biogenetically related obovanine, oxoputerine and (?)-romneine, not known as a natural product, were obtained from the bark of L. novae-zelandiae. The occurrence of (R)-norlaudanosoline-derived alkaloids in L. novae-zelandiae is a distinctive feature of this tree. Neither L. novae-zelandiae nor L. philippiana accumulate dimeric benzylisoquinoline alkaloids to any appreciable extent in the trunk bark, differing in this respect from L. sempervirens, the only other Laurelia species.     

Quinoline and indolopyridoquinazoline alkaloids from Vepris louisii

The structures of two new 2-quinolone alkaloids from the stem bark of Vepris louisii, N-methylpreskimmianine [7,8 - dimethoxy - 3 - (3 - methylbut - 2 - enyl) - 1 - methyl - 2 - quinolone] and veprisine (7,8 - dimethoxy - N - methylflindersine) have been deduced from their spectral data and confirmed by partial synthesis from known compounds. Two minor indolopyridoquinazoline alkaloids were also isolated and identified as the already known 1-hydroxyrutaecarpine and the hitherto unknown 7,8-dehydro derivative of 1-hydroxyrutaecarpine.