Isolation and structure of buxaminol-G,an alkaloid from Buxus papilosa

A new alkaloid, buxaminol-G, has been isolated from the alcoholic extract of the leaves of Buxus papilosa, and its structure assigned on the basis of spectroscopic studies.     

Structure of solanaviol,a new steroidal alkaloid from Solanum aviculare

A new alkaloid solanaviol ((22R, 25R)-spirosol-5-ene-3β,12β-diol) was isolated from Solanum aviculare in addition to solasodine as one of the main alkaloids. The structure of solanaviol was established by NMR spectroscopy, as well as by conversion into a known pregnane derivative and solasodine.     

Solanopubamine,a steroidal alkaloid from Solanum pubescens

Aerial parts of Solanum pubescens yielded a new steroidal alkaloid, solanopubamine, the structure of which was elucidated as 3β-amino-5α,22αH,25βH-solanidan-23β-ol by ¹³C NMR, ¹H NMR, IR, mass spectral analysis and chemical degradation methods.     

Structure of the steroidal alkaloid muldamine and its deacetyl derivative

Spectral techniques have established the structure of muldamine from Veratrum californicum as (22S, 25S)-22,26-epiminocholest-5-ene-3β,16     

Aculeamine,a solanocapsine-type steroidal alkaloid from Solanum aculeatum

A new solanocapsine-type alkaloid named aculeamine has been isolated from roots of Solanum aculeatum and its structure elucidated by physical methods including X-ray analysis as 22,26-epimino-22β-methoxy- 16α,23-epoxy-5α,22αH,25βH-cholestane-3β-ol. The corresponding 23β-ethoxy compound was also isolated as an artefact.     

Havanine—a steroidal alkaloid glycoside from Solanum havanense

A new steroidal alkaloid glycoside named havanine has been isolated from the leaves of Solanum havanense and its structure elucidated by spectral data as (25S)-O(3)-β-D-glucopyranosyl-16α-acetoxy-22,26-epiminocholesta-5,22(N)-dien-3β-ol.     

Glycolone,a quinolone alkaloid from Glycosmis pentaphylla

Glycolone, a quinolone alkaloid has been isolated from the leaves of Glycosmis pentaphylla. The structure of the compound has been established as 4,8-dimethoxy-3-(3-methyl but-2-enyl)-2-quinolone from physical and chemical evidences.     

Ravesilone,a quinolone alkaloid from Ravenia spectabilis

A new quinolone alkaloid designated ravesilone has been isolated from the leaves of Ravenia spectabilis. From spectral evidence the structure of the compound has been established as 3,4,5,6-tetrahydro-7-hydroxy-2,2,6-trimethyl-5-oxo-2H-pyrano[3,2-c]quinoline.     

Scholaricine,an alkaloid from alstonia scholaris

A new alkaloid, scholaricine, has been isolated to which structure 2 (demethylscholarine) has been assigned.     

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).     

3-Desamino-3α-hydroxysolanocapsine—a steroidal alkaloid from Solanum aculeatum

A new steroidal alkaloid has been obtained from roots of Solanum aculeatum and its structure elucidated by IR, NMR and mass spectral studies as 3-desamino-3β-hydroxysolanocapsine.     

Cardenagenin,a steroidal sapogenin from Calibanus hookerii

One new steroidal sapogenin with an open side chain was isolated from the rhizome of Calibanus hookerii. The structure has been determined by spectroscopic studies as 14α-hydroxy-calibagenin.     

Bioactive steroidal alkaloid glycosides from Solanum aculeastrum.

Solanum aculeastrum Dunal was investigated for the presence of molluscicidal compounds. This led to the isolation of solaculine A, from the root bark in addition to known steroidal alkaloids; solamargine and beta-solamarine from the berries. The structures were elucidated by spectroscopic techniques. Molluscicidal activity of the aqueous extracts of the berries and root bark, and the isolated compounds were investigated.     

Steroidal alkaloid saponins and steroidal saponins from Solanum surattense

A rare 16β-H steroidal alkaloid saponin (1), an avenacoside-type saponin (2), two steroidal saponins (4, 5), one revised-structure steroidal saponin (3) and six known compounds (6-11) were isolated from aerial parts of Solanum surattense Burm. f. Their structures were established on the basis of physical data, as well as by using spectroscopic (HRESIMS, 1D and 2D NMR), and chemical analysis methods. Compounds 1 and 11 showed cytotoxicity against A549 cell line with IC₅₀ values of 20.3 and 15.7 μM, respectively.     

Sativanine-g,a cyclopeptide alkaloid from Zizyphus sativa

In addition to the already described peptide alkaloids from the bark of Zizyphus sativa, a new compound of this class, sativanine-G, has been isolated and its structure elucidated. This alkaloid contains a 13-membered ring system and belongs to the nummularine-C class.