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Biomedical subjects

F R Chang

Publications and source records attributed to F R Chang.

11 recordsLinked to original sources
PubMed1998

Acetogenins from seeds of Annona reticulata.

Chromatography of an ethyl acetate extract of seeds of Annona reticulata led to the isolation of a new cytotoxic gamma-lactone acetogenin, cis-/trans-isomurisolenin, along with six known cytotoxic acetogenins, annoreticuin, annoreticuin-9-one, bullatacin, squamocin, cis-/trans-bullatacinone and cis-/trans-murisolinone. Structures of these compounds were established by means of mass and related spectral experiments. Some of the compounds isolated, showed potent cytotoxicities against Hep. 2,2,15, Hep. G2, KB and CCM2, four cancer cell-lines.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Two new 7-dehydroaporphine alkaloids and antiplatelet action aporphines from the leaves of Annona purpurea.

Bioactivity-directed fractionation led to the isolation of two new 7-dehydroaporphine alkaloids, 7-hydroxy-dehydrothalicsimidine (1) and 7-formyl-dehydrothalicsimidine (2), along with the five known alkaloids, thalicsimidine (3), norpurpureine (4), N-methyllaurotetanine (5), lirinidine (6) and N-methylasimilobine (7), from the leaves of Annona purpurea. Structural elucidation of these compounds was established by mass and spectroscopic analyses. Among them, 1, 3, 4, 6 and 7 exhibited significant inhibition of collagen, arachidonic acid and platelet activating factor-induced platelet aggregation; 1 also showed inhibition against thrombin-induced platelet aggregation.

Alkaloids↗
PubMed1998

Chemical constituents from Cassytha filiformis II.

Using a bioassay-directed fractionation method, three new compounds, including an aporphine alkaloid, cassyformine (4); an oxoaporphine alkaloid, filiformine (8), and a lignan, (+)-diasyringaresinol (10), along with 14 known compounds, were further isolated and characterized from the MeOH extract of the fresh herbs of Cassytha filiformis. Among the isolates of this plant, cathafiline (1), cathaformine (2), actinodaphnine (3), N-methylactinodaphnine (5), predicentrine (6), and ocoteine (7) exhibited significant antiplatelet aggregation activity.

Alkaloids↗
PubMed1998

Bioactive kaurane diterpenoids from Annona glabra.

Phytochemical analysis of the fruits of Annona glabra yielded two new kaurane diterpenoids, annoglabasin A (methyl-16 beta-acetoxy-19-al-ent-kauran-17-oate)(1) and annoglabasin B (16 alpha-hydro-19-acetoxy-ent-kauran-17-oic acid)(2), along with 11 known kaurane derivatives (3-13). The structures of the new compounds were established by spectral and chemical evidence. Among these, methyl-16 alpha-hydro-19-al-ent-kauran-17-oate (11) exhibited mild activity against HIV replication in H9 lymphocyte cells, and 16 alpha-17-dihydroxy-ent-kauran-19-oic acid (4) showed significant inhibition of HIV-reverse transcriptase.

Anti-HIV Agents↗
PubMed1998

Antiplatelet aggregation constituents from Annona purpurea.

Bioactivity-directed fractionation led to the isolation of 19 compounds, including three oxoaporphines, oxopurpureine (5), oxonuciferine (6), and oxoglaucine (7); three aporphines, (+)-predicentrine (8), (-)-glaucine (9), and thalbaicalidine (10); one aporphine sensu stricto, N-formyl-purpureine (11); one proaporphine, glaziovine; one phenanthrene, thalicpureine (12); two 6a,7-dehydroaporphines, dehydrolirinidine (13) and 7-hydroxy-dehydroglaucine (14); four flavonoids, quercetin-3-O-rhamnoside, kaempferol-3-O-rhamnoside, isorhamnetin-3-O-rhamnoside, and tanarixetin-3-O-rhamnoside; one purine, adenine; one lactam amide, squamolone; and two steroids, beta-sitosterol and beta-sitosterol-beta-D-glucoside from the MeOH extract of the leaves of Formosan Annona purpurea. Among them, 11-14 were characterized as new compounds and alkaloids, 5-8, 10, and 12-14 exhibited significant antiplatelet aggregation activity.

Alkaloids↗
PubMed1996

Identification of ent-16 beta, 17-dihydroxykauran-19-oic acid as an anti-HIV principle and isolation of the new diterpenoids annosquamosins A and B from Annona squamosa.

Phytochemical analysis of the fruits of Annona squamosa yielded 12 known kaurane derivatives (1-11, 13) and two new kaurane diterpenoids, which have been named annosquamosin A (16 beta-hydroxy-17-acetoxy-ent-kauran-19-al) (12) and annosquamosin B (19-nor-ent-kaurane-4 alpha,16 beta,-17-triol) (14). The structures of the new compounds were established by spectral analyses and chemical evidence. Among these 14 compounds, 16 beta, 17-dihydroxy-ent-kauran-19-oic acid (2) showed significant activity against HIV replication in H9 lymphocyte cells with an EC50 value of 0.8 microgram/mL (therapeutic index > 5).

Antiviral Agents↗
PubMed1993

Studies on the acetogenins of Formosan annonaceous plants. II. Cytotoxic acetogenins from Annona reticulata.

Using cytotoxicity as a guide to fractionation, one novel acetogenin, annoreticuin-9-one [3], and four known cytotoxic acetogenins, squamone [4], solamin [5], annomonicin [6] and rolliniastatin 2 [7], were isolated from active extracts of the leaves of the Formosan plant Annona reticulata. Their structures were elucidated on the basis of uv, ir, 1H- and 13C-nmr, and ms data of the natural compounds and their derivatives.

Animals↗
PubMedDate not supplied

The crystal structure and cytotoxicity of goniodiol-7-monoacetate from Goniothalamus amuyon.

The styrylpyrone, goniodiol-7-monoacetate [1] [6R-(7R,8R-dihydro-7-acetoxy-8-hydroxystyryl)-5, 6-dihydro-2-pyrone], has been isolated from Goniothalamus amuyon, and its detailed molecular structure has been determined by X-ray crystallographic analysis. Goniodiol-7-monoacetate showed potent (ED50 values less than 0.1 microgram/ml) cytotoxicities against KB, P-388, RPMI, and TE671 tumor cells.

Animals↗