Protopine-N-oxide,an alkaloid from Bocconia cordata

The structure of a minor alkaloid of Bocconia cordata has been deduced as protopine-N-oxide by spectroscopic methods and confirmed by synthesis.     

Orientalidine and isothebaine from cell cultures of Papaver bracteatum

Orientalidine, isothebaine and sanguinarine were isolated from callus cultures of Papaver bracteatum when grown on M & S medium with various horm     

Alpinine,epialpinine and other alkaloids from Papaver bracteatum

Alpinine, epialpinine, muramine and protopine were identified as alkaloids of Papaver bracteatum. The earlier reported presence of alpinine is revised. The structures of codeine and neopine, earlier reported for this species, are assessed. Screening for the presence of O-methylflavinantine was negative.     

Protostrychnine,a new alkaloid from Strychnos nux-vomica

The tertiary bases from a sample of Strychnos nux-vomica contain, as well as the expected strychnine and brucine, an unusually high proportion of 4-hydroxy and 4-hydroxy-3-methoxy compounds. The biosynthetic implications of the isolation of a new alkaloid, 12β,13α-dihydro-12α-hydroxyisostrychnine, named protostrychnine, are discussed.     

Glycarpine,a new alkaloid from Glycosmis cyanocarpa

Glycarpine, a new furoquinolone alkaloid and evolitrine have been isolated from Glycosmis cyanocarpa.     

Pelargonidin 3-malonylsophoroside from the red Iceland poppy,Papaver nudicaule

Pelargonidin 3-malonylsophoroside was characterized as a flower pigment in a red form of the Iceland poppy, Papaver nudicaule.     

Nupharopumiline,a new quinolizine alkaloid from Nuphar pumila

A new quinolizine alkaloid, (+)-nupharopumiline, has been isolated from the rhizomes of Nuphar pumila. It has been shown by spectroscopic and chemi     

The relationship between l-dopa decarboxylase in the latex of Papaver somniferum and alkaloid formation

The presence of l-dopa decarboxylase has been demonstrated in poppy latex utilising l-dopa-1-[¹⁴C] and l-dopa-3-[¹⁴Cl] as substrates. The enzyme appeared to have maximum activity at pH 7.2 and showed both substrate and pyridoxal phosphate inhibition. The substrates l-tyrosine, l-phenylalanine and l-histidine were also decarboxylated. l-dopa decarboxylase was found to occur solely in the latex supernatant fraction. The possible involvement of this enzyme in alkaloid biosynthesis in the latex is discussed.     

Piplartine-dimer A,a new alkaloid from Piper tuberculatum

Piplartine-dimer A (1), a dimer of the known pyridone alkaloid piplartine, was isolated from root bark of Piper tuberculatum. It is accompanied by piplartine (3) and 3,4,5-trimethoxycinnamic acid.     

Vasicol,a new alkaloid from Adhatoda vasica

A novel alkaloid isolated from the roots of Adhatoda vasica has been characterized as 1,2,3,4,9,11 hexahydro pyrrolo (2,1-b) quinazolin-3,11 diol by chemical and spectroscopic methods. Vasicinone has also been isolated from the roots of this plant.     

Rapid TLC/GC-MS identification of acetylcholinesterase inhibitors in alkaloid extracts

Alkaloid extracts from 12 plant species of the families Amaryllidaceae, Fumariacae and Papaveraceae were studied with respect to their acetylcholinesterase inhibitory activity and alkaloid patterns. Fifty-three alkaloids were identified by GC-MS, including known acetylcholinesterase (AChE) inhibitors such as galanthamine, epigalanthamine, sanguinine and epinorgalanthamine in extracts of Amaryllidaceae plants and protopine in extracts of Fumariaceae and Papaveraceae plants. The galanthamine-containing extracts of the amaryllidaceous plants were found to be the most active while the extract of Corydalis bulbosa was the most active among the extracts of the tested plants from the Fumariaceae and Papaveraceae plants. TLC bioautographic assay, preparative TLC and GC-MS analysis were combined to identify the active compounds in the studied extracts. Galanthamine was isolated from the known AChE inhibitors in the extracts of Amaryllidaceae plants. Corydaline, bulbocapnine and stylopine were found to be active in the extracts of plant species of the families Fumariaceae and Papaveraceae. Available standards of deshydrocorydaline--a precursor of corydaline, corydaline and stylopine--were tested for AChE inhibitory activity. Deshydrocorydaline and corydaline showed potent inhibitory activity comparable with that of the positive control galanthamine.     

Zanoxyline—a new alkaloid from stem bark of Zanthoxylum oxyphyllum

The EtOH extract of stem bark of Zanthoxylum oxyphyllum yielded rhetsinine and a new alkaloid 1-(4′methoxy benzyl)-6,7-dimethoxy N:N dimethyl 1,2,3,4 tetrahydroisoquinolinium hydroxide provisionally named zanoxyline.