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Pluronic F127 (PF127) is a copolymer which forms thermosensitive hydrogels. Hyaluronic acid (HA) was grafted to PF127 to form a new hydrogel matrix (HP) for delivery of cisplatin and carboplatin. The physicochemical properties and drug delivery of the graft were examined in this study. HP system (20% HP copolymer in water) exhibited a similar sol-gel transition temperature (28.3 degrees C) as PF127 system (20% PF127 copolymer in water) but with a shorter gelling process. A stronger structure was obtained by HP system according to scanning electron microscopic (SEM) images and viscosity kinetics. In vitro release test showed the sustained-release characteristics of hydrogels entrapped with cisplatin and carboplatin. The drug release rate from HP hydrogel was slower than that from PF127 hydrogel. The reduction of drug release by HP system as compared to the control solution was more significant for cisplatin than for carboplatin. Such a thermosensitive hydrogel may be advantageous as an injectable therapeutic formulation for anticancer treatment.

One new 1,3-diphenylpropane, viscolin (1), and one new flavanone, (2S)-7,4'-dihydroxy-5,3'-dimethoxyflavanone (2), together with thirty-nine known compounds, which included eleven known flavanones, two chromones, fourteen benzenoids, one inositol, two pyrimidines, four triterpenoids and five steroids, were isolated and characterized from Viscum coloratum. Structures of new compounds were determined by spectral analysis. Among them, viscolin (1) showed the most significant inhibition on superoxide anion generation by human neutrophils in response to fMLP (formyl-L-methionyl-L-leucyl-L-phenylalanine).

Further investigation of the methanolic extract of Fissistigma latifolium resulted in two new compounds whose structures were assigned as 2,5,6,7-tetramethoxyflavan (1) and 2'-hydroxy-4',5',6'-trimethoxybenzil (2). These two compounds were determined on the basis of chemical and spectroscopic evidences. Compound 2 is the first report of benzil from Fissistigma species. 2,5,6,7-Tetramethoxyflavan (1) showed a potent inhibitory effect on superoxide anion production in formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP)/cytochalasin B (CB)-activated human neutrophils.

Four new compounds, three phenanthrene derivatives, aristolochic acid-III methyl ester (1), cepharanone C (2), and sodium 7-hydroxyl-8-methoxyaristolate (3), and the benzoate derivative, sodium 3,4-dimethoxybenzoate (4), together with 53 known compounds were isolated and characterized from the fresh root and stem of Aristolochia cucurbitifolia. Their structures were elucidated by spectral analyses and chemical transformations. The cytotoxicity and antiplatelet activity of the isolated compounds are also discussed.

Reinvestigation of the root of Rhinacanthus nasutus afforded, in addition to rhinacanthin-A to -D reported previously, two new dimethyldihydropyranonaphthoquinone esters (5, 6) and eight new 2-hydroxy-1,4-naphthoquinone esters (7-14) were isolated. The stereochemistry of rhinacanthin-A was determined as the R configuration. Compounds rhinacanthin-G to -N, belong to a class of 2-hydroxy-3-(3-hydroxy-2,2-dimethylpropyl)-1,4-naphthoquinone esters, and so far have been isolated only in this plant. Their biosynthesis is also discussed.

Two new flavanones, (2S)-pinocembrin 7-O-[beta-D-apiosyl(1-->2)]-beta-D-glucoside (1), and (2S)-pinocembrin 7-O-[cinnamoyl(1-->5)-beta-D-apiosyl(1-->2)]-beta-D-glucoside (2) together with eighteen known compounds, which include five known flavanones, nine benzenoids, one inositol and three triterpenoids, were isolated and characterized from fresh Viscum articulactum. Structures of new compounds were determined by spectral analysis. Among them, oleanolic acid (18) showed a significant inhibition effect on superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP).

Continuing our investigation on the bioactive compounds from the plant of Aristolochia genus in Taiwan, we isolated one new aristolochic acid derivative, aristolochic acid-VII methyl ester; one new dihydrophenanthrenelactone, aristolide-C; four new benzenoids, 2'-hydroxyethyl 4-hydroxybenzoate, ariscucurbin-A, -B and -C, together with forty-six known compounds from the fresh Aristolochia cucurbitifolia.

Investigation of the fresh leaves of Aristolochia heterophylla resulted in the isolation of three new compounds, madolin-N (1), madolin-O (2) and aristophyll-C(3), together with 42 known compounds. Their structures were determined by spectral method.

Two new phenanthrene derivatives, aristoliukine-A, -B, and a benzenoid, sodium (2R)-(p-hydroxyphenyl)-lactate, together with thirty-three known compounds were isolated from the fresh leaves of Aristolochia kaempferi. Structures were elucidated by spectral analysis. Among the new compounds, sodium (2R)-(p-hydroxyphenyl)lactate was determined to be in the salt form by IR and 1 H-NMR methods.

Two novel compounds, aristolide-A(1) and -B(2) were isolated from the root and stem of Aristolochia heterophylla HEMSL. Their structures were determined by spectral analysis. This is the first instance of the isolation of dihydrophenanthrenelactones from a natural source.

Seven denitroaristolochic acids, incuding four new compounds, sodium aristofolin-A, aristofolin-B-D and three known compounds, aristofolin-A, aristolic acid and methyl aristolate were isolated from the leaves of Aristolochia cucurbitifolia. Their structures were determined by spectroscopic methods.