Fumiko Abe

9α-hydroxypinoresinol, 9α-hydroxymedioresinol and related lignans from Allamanda neriifolia

Abstract 9α-Hydroxypinoresinol and 9α-hydroxymedioresinol were isolated along with seven known lignans, pinoresinol, medioresinol, syringaresinol, and their glucosides, from Allamanda neriifolia.

Alkaloids from the leaves of Alstonia scholaris in Taiwan, Thailand, Indonesia and the Philippines☆

Abstract From the leaves of Alstonia scholaris , collected in Taiwan, Thailand, Indonesia and Philippines, several new alkaloids, 19-epischolaricine, N b -methylscholaricine, N a -methylburnamine and vallesamine N b -oxide were isolated and their structures determined by spectral and chemical methods. The leaves of plants from Taiwan and Thailand showed similar alkaloid patterns, with picrinine, nareline and alschomine as the major alkaloids. The leaves of plants from Indonesia and Philippines showed different patterns from those of plants from Taiwan or Thailand, and contained mainly angustilobine B group. Picraline and its homologues were obtained from the leaves of Indonesian plants.

Indole alkaloids from leaves and stems of Leuconotis eugenifolius

Abstract From leaves and stems of Leuconotis eugenifolius , six indole alkaloids were isolated and five were identified as yohimbine, β-yohimbine, leuconolam, 21- O -methyl-leuconolam and rhazinaline N b -oxide. The new alkaloid, having a pentacyclic diazaspiro system, was determined to be a diazaspiroleuconolam and named leuconoxine. Other constituents identified were 3β-hydroxy-5α,6α-epoxy-β-ionone, epigallocatechin, loganic acid, 2-methyl-3-buten-2-ol rutinoside and four flavonol glycosides.

Lignan glycosides from Parsonsia laevigata

Abstract Bis- O -rhamnosides of lariciresinol, 5,5′-dimethoxylariciresinol and secoisolariciresinol, and pinoresinolapiosyl (1 → 2)-glucoside were isolated from Parsonsia laevigata .

Presence of cardenolides and ursolic acid from oleander leaves in larvae and frass of Daphnis nerii

Cardenolide glycosides from larvae of the sphingid moth Daphnis nerii reared on oleander leaves, and those from their frass, were examined by HPLC and then isolated preparatively. Most of the cardenolide triosides in the leaves were detected as their corresponding monosides in the larval and frass extracts. From the frass, adynerin was obtained in large amounts, along with nine cardenolide monosides. A decrease of oleandrin due to deacetylation and an increase of adynerin in the frass are discussed.

Trypanocidal constituents in plants: 7. Mammea-type coumarins

Calophyllum brasiliense and Mammea americana (Clusiaceae) are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 microg/ml. Coumarins with a cyclized gamma,gamma-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 microg/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds.

Pyrrolizidine alkaloids mediate host-plant recognition by ovipositing females of an old world danaid butterfly, Idea leuconoe

A giant danaid butterfly, Idea leuconoe, specializes on apocynaceous plants such as Parsonsia laevigata, which has been reported to contain pyrrolizidine alkaloids. Females of I. leuconoe deposited eggs in response to methanolic extract of P. laevigata, and subsequent bioassay-guided fractionation of the extract revealed that phytochemicals crucial for host recognition by ovipositing females are Parsonsia-specific macrocyclic pyrrolizidine alkaloids including parsonsianine, parsonsianidine, and 17-methylparsonsianidine. Parsonine, another P. laevigata pyrrolizidine component with a keto-dihydropyrrolizine moiety that is closely related in structure to male pheromones of the butterfly, and several nonhost pyrrolizidine alkaloids were entirely inactive. We interpret these data as strong evidence for an ancestral association through herbivory between danaid butterflies and pyrrolizidine alkaloids.

Iridals from Belamcanda chinensis and Iris japonica

Abstract Three new iridals were isolated, along with two known compounds; (+)-6R,10S,11S,14S,26R)-26-hydroxy-15-methylidenespiroirid-16-enal and iso-iridogermanal, from the rhizomes and roots of Belamcanda chinensis and Iris japonica. The new iridals were determined to be 28-acetoxy-14,15-dihydro-26-hydroxy-19-methylidenespiroirida-15,17-dienal (belamcandal), its deacetyl derivative and 16-O-acetyl iso-iridogermanal. Their fatty acid esters were also isolated. Belamcandal stimulates throat membrane.

Cardenolide triosides of oleander leaves

Abstract Polar glycosides from the air-dried leaves were re-examined, and gentiobiosyl-nerigoside and gentiobiosylbeaumontoside isolated along with the major trioside, gentiobiosyl-oleandrin. Minor triosides also include glycosides of8β-hydroxy- and Δ 16 -8β-hydroxy-digitoxigenin, and Δ 16 -neriagenin, along with glycosides of known cardenolides, oleandrigenin, digitoxigenin, adynerigenin, neriagenin and their Δ 16 -derivatives.

Minor daphnane-type diterpenoids from Wikstroemia retusa

In addition to huratoxin, pimelea factor P2, and wikstroelides A-G from the fresh bark, eight daphnane-type diterpenoids, wikstroelides H-O, were isolated from the bark and stem, and their structures established. Cytotoxicity was assayed on some wikstroelides.