Flavonoids from the leaves and stems of Sedum japonicum var. senanense and their antioxidant activity

Twenty flavonoids (1-20) were isolated from the leaves and stems of Sedum japonicum var. senanense endemic to Japan. Among them, nine compounds were reported in nature for the first time, and identified as herbacetin 3-O-neohesperidoside-8-O-(2‴-acetylxyloside) (2), gossypetin 8-O-(2″-acetylxyloside) (4), gossypetin 8-O-(3″-acetylxyloside) (5), gossypetin 3-O-glucoside-8-O-(3‴-acetylxyloside) (9), gossypetin 3-O-glucoside-8-O-(2‴,3‴-diacetylxyloside) (10), gossypetin 3-O-neohesperidoside-8-O-xyloside (11), gossypetin 3-O-neohesperidoside-8-O-(2⁗-acetylxyloside) (12), gossypetin 3-O-neohesperidoside-8-O-(3⁗-acetylxyloside) (13) and gossypetin 3-O-glucoside-8-O-xylofuranoside (14) by UV spectral survey, HR-MS, LC-MS, acid hydrolysis, NMR including 1H and 13C NMR, COSY, NOESY, HSQC and HMBC. Moreover, nine major flavonoids were surveyed for antioxidant activity by H-ORAC method. As the results, gossypetin 3-O-glucoside-8-O-(2‴-acetylxyoside) (8) showed the highest antioxidant activity. Conversely, gossypetin 3-O-neohesperidoside-8-O-xyloside (11) and gossypetin 3-O-neohesperidoside-8-O-(2⁗-acetylxyloside) (12) which attach neohesperidose showed the lowest values.

Pharmaceutical Food Science: Search for Bio-Functional Molecules Obtained from Natural Resources to Prevent and Ameliorate Lifestyle Diseases

In this review, our resent pharmaceutical food science research for bio-functional molecules obtained from natural resources that contribute to i) suppression of postprandial blood glucose elevation and/or improvement of glucose tolerance and ii) reduction of visceral fat accumulation and improvement of lipid metabolism were summarized. Based on studies using MONOTORI science, salacinol (1), neokotalanol (4), and trans-tiliroside (20) have been approved or notified by the Consumer Affairs Agency in Japan as functional substances in food with health claims, Food for Specified Health Use and Food with Functional Claims.

Flavonoids from Sedum japonicum subsp. oryzifolium (Crassulaceae)

Twenty-two flavonoids were isolated from the leaves and stems of Sedum japonicum subsp. oryzifolium (Crassulaceae). Of these compounds, five flavonoids were reported in nature for the first time, and identified as herbacetin 3-O-xyloside-8-O-glucoside, herbacetin 3-O-glucoside-8-O-(2′′′-acetylxyloside), gossypetin 3-O-glucoside-8-O-arabinoside, gossypetin 3-O-glucoside-8-O-(2′′′-acetylxyloside) and hibiscetin 3-O-glucoside-8-O-arabinoside via UV, HR-MS, LC-MS, acid hydrolysis and NMR. Other seventeen known flavonoids were identified as herbacetin 3-O-glucoside-8-O-arabinoside, herbacetin 3-O-glucoside-8-O-xyloside, gossypetin 3-O-glucoside-8-O-xyloside, quercetin, quercetin 3-O-glucoside, quercetin 3-O-xylosyl-(1→2)-rhamnoside-7-O-rhamnoside, quercetin 3-O-rhamnoside-7-O-glucoside, kaempferol, kaempferol 3-O-glucoside, kaempferol 7-O-rhamnoside, kaempferol 3,7-di-O-rhamnoside, kaempferol 3-O-glucoside-7-O-rhamnoside, kaempferol 3-O-glucosyl-(1→2)-rhamnoside-7-O-rhamnoside, kaempferol 3-O-xylosyl-(1→2)-rhamnoside, kaempferol 3-O-xylosyl-(1→2)-rhamnoside-7-O-rhamnoside, myricetin 3-O-glucoside and cyanidin 3-O-glucoside. Some flavonol 3,8-di-O-glycosides were found in Sedum japonicum subsp. oryzifolium as major flavonoids in this survey. They were presumed to be the diagnostic flavonoids in the species. Flavonoids were reported from S. japonicum for the first time.

Chemical constituents and absolute configuration of megastigmanes' isolated from Sedum sarmentosum Bunge

Phytochemical investigation of a methanolic extract of Sedum sarmentosum collected from Vietnam resulted in the isolation of a new megastigmane glucoside, named sedumoside K (1), together with 17 previously reported compounds (2-18). Structural elucidation of the new compound was achieved by HRFABMS, NMR spectroscopic analysis, acid hydrolysis and quantum ECD calculations. The absolute configuration of compounds 2-6 has been revised. The major isolates were tested for cytotoxic activity against HeLa human cervical cancer cells, and all showed moderate activities.

A Review of Biologically Active Natural Products from a Desert Plant Cistanche tubulosa

An Orobanchaceae plant Cistanche tubulosa (SCHENK) WIGHT (Kanka-nikujuyou in Japanese), which is one of the authorized plant resources as Cistanches Herba in both Japanese and Chinese Pharmacopoeias, is a perennial parasitic plant growing on roots of sand-fixing plants. The stems of C. tubulosa have traditionally been used for treatment of impotence, sterility, lumbago, and body weakness as well as a promoting agent of blood circulation. In recent years, Cistanches Herba has also been widely used as a health food supplement in Japan, China, and Southeast Asian countries. Here we review our recent studies on chemical constituents from the stems of C. tubulosa as well as their bioactivities such as vasorelaxtant, hepatoprotective, and glucose tolerance improving effects.

Anti-radical flavonol glycosides from the aerial parts of Cleome chelidonii L.f

Eleven previously undescribed flavonoid glycosides, named cleomesides C-M, along with five known compounds, were isolated from the aerial parts of Cleome chelidonii L.f. (Cleomaceae). All flavonol glycosides were esterified derivatives of 3,7-O-diglycosides of quercetin or kaempferol. Their structures were elucidated by analysis of the 1D and 2D NMR spectra, HR-ESI-MS data, UV spectra, optical rotation and by comparison with literature data. The DPPH radical scavenging properties of the flavonoid glycosides were studied in order to appreciate the effect of the glycoside parts and of the ester groups on this activity compared with the quercetin and kaempferol aglycones. An acetate at position 3 of rhamnose linked to C-7 of flavonol, gave compounds with the strongest antiradical activity. An aromatic ester group at position 6 of terminal glucose of diglycoside chain linked to C-3 of flavonol did not seem to influence the antiradical activity.

Flavonoids with Hepatoprotective Activity from the Leaves of Cleome chelidonii

One new flavonol glycoside, named cleomeside C (1), together with eight known flavonol glycosides (2–9) were isolated by various chromatography methods from the leaves of Cleome chelidonii. Their structures were elucidated by IR, UV, HR-ESI-MS, NMR (1D & 2D) experiments. Compounds 2–8 were isolated for the first time from the genus Cleome. The cytotoxicity and hepatoprotective activity in HepG2 human hepatoma cell line of compounds (1–3 and 6) were measured by MTT assay. At the concentration of 25 μM and 50 μM, compound 2 as well as compound 3 at 25 μM showed cytotoxic activity (cell viability was decreased 21.7%, 31.8% and 21.8%, respectively, compared to control). Compounds 2 and 6 expressed hepatoprotective effect at the concentration of 100 μM with prevention percentage of 32.3% and 34.3%, respectively, compared to that of 80.3% of quercetin positive control).

Hepatoprotective Limonoids from Andiroba (Carapa guianensis)

Three gedunin-type limonoids, gedunin (1), 6α-acetoxygedunin (2), and 7-deacetoxy-7-oxogedunin (3), which were isolated from the seed and flower oils of andiroba (Carapa guianensis Aublet, Meliaceae), exhibited hepatoprotective effects at doses of 25 mg/kg, p.o. against d-galactosamine (d-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. To characterize the mechanisms of action of 1-3 and clarify the structural requirements for their hepatoprotective effects, 17 related limonoids (1-17) isolated from the seed and/or flower oils of C. guianensis were examined in in vitro studies assessing their effects on (i) d-GalN-induced cytotoxicity in primary cultured mouse hepatocytes, (ii) LPS-induced nitric oxide (NO) production in mouse peritoneal macrophages, and (iii) tumor necrosis factor-α (TNF-α)-induced cytotoxicity in L929 cells. The mechanisms of action of 1-3 are likely to involve the inhibition of LPS-induced macrophage activation and reduced sensitivity of hepatocytes to TNF-α; however, these compounds did not decrease the cytotoxicity caused by d-GalN. In addition, the structural requirements of limonoids (1-17) for inhibition of LPS-induced NO production in mouse peritoneal macrophages and TNF-α-induced cytotoxicity in L929 cells were evaluated.

Comparison of Antioxidant Capability after Isopropanol Salting-Out Pretreatment and n-Butanol Partition Extraction, and Identification and Evaluation of Antioxidants of Sedum formosanum N.E.Br

Crude extracts of Sedum formosanum N.E.Br. obtained from n-butanol partition (BP) and isopropanol salting-out pretreatment (ISP) were analyzed using antioxidation assays. The results indicated that the extract from ISP contained more potent antioxidants and thus exhibited more antioxidant activity in all the assays. The superoxide radical-scavenging activity and inhibition of nitric oxide radicals achieved after ISP were 3.65 and 2.18 times higher than those achieved through BP, respectively. Eight bioactive natural products were isolated and identified according to an analysis of antioxidation activity in different fractions of the ISP crude extract, namely three cyanophoric glycosides 1-3, three flavonoids 4-6 and two phenolic compounds (7 and a new compound 8). Among them, compounds 5 and 6 exhibit the highest antioxidation capability, and the ISP is suitable for obtaining compounds 5 and 6 using HPLC chromatograms. Therefore, ISP is an excellent extraction technology that can be used to extract antioxidant compounds in the nutraceutical and pharmaceutical industries.

Bioactive Constituents from the Aerial Parts of Lippia triphylla

Five new compounds, lippianosides A (1), B (2), C (3), D (4), and E (5), along with 26 (6-31) known ones were obtained from the 95% EtOH extract of Lippia triphylla (L. triphylla) aerial parts collected from Rwanda, Africa. Among the known compounds, 11 and 17-30 were isolated from the Lippia genus for the first time. In addition, 12, 13, and 16 were firstly obtained from this species. The structures of them were elucidated by chemical and spectroscopic methods. The antioxidant and triglyceride accumulation inhibition effects of the 31 compounds were examined in L6 cells and HepG2 cells, respectively.

Chemical structures and hepatoprotective effects of constituents from Cassia auriculata leaves

An 80% aqueous acetone extract of Cassia auriculata leaves was found to show a protective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the 80% aqueous acetone extract, we isolated a new benzocoumarin glycoside, avaraoside I (1), and a new flavanol dimer, avaraol I (2), together with 29 known constituents. The structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. In addition, three isolated compounds, pseudosemiglabrin (15, 0.0011%), (2S)-7,4'-dihydroxyflavan(4β→8)-catechin (22, 0.00075%), and (2S)-7,4'-dihydroxyflavan(4β→8)-gallocatechin (23, 0.092%), displayed hepatoprotective effects equivalent to that of the hepatoprotective agent, silybin.

Rare syringyl acylated flavonol glycosides from the aerial parts of Leonurus japonicus Houtt

Five new syringyl acylated flavonol glycosides, named leonurusoides A (1), B (2), C (3), D (4), and E (5), together with one known one 6 were obtained from the aerial parts of Leonurus japonicus. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Compounds 1−6 showed triglyceride (TG) accumulation inhibitory effects in free fatty acid-induced HepG2 cells.

Triglyceride accumulation inhibitory effects of phenylpropanoid glycosides from Boschniakia rossica Fedtsch et Flerov

Bioassay-guided fractionation led to isolation of five new phenylpropanol glycosides, rossicasides G (1), H (2), I (3), J (4), and K (5), together with seven known compounds (6-12) from Boschniakia rossica. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Activity screening results showed that some isolates had TG accumulation inhibitory effects in HepG2 cells. Furthermore, the structure-activity relationship was partly clarified.

Flavonol glycosides, nigelflavonosides A-F from the whole plant of Nigella glandulifera (Ranunculaceae)

Six new flavonol glycosides, nigelflavonosides A-F (1-6), together with a known compound (7) were isolated from the whole plant of Nigella glandulifera Freyn et Sint (Ranunculaceae). Structure elucidation, especially the localization of the glycosyl or acetyl groups, and complete (1)H- and (13)C-NMR assignments of these compounds were carried out using one- and two-dimensional NMR measurements, including (1)H- and (13)C-NMR, (1)H-(1)H COSY, TOCSY, HMQC, HMBC and NOESY, in addition to HRESI-TOF-MS experiments.

Hepatoprotective amide constituents from the fruit of Piper chaba: Structural requirements, mode of action, and new amides

The 80% aqueous acetone extract from the fruit of Piper chaba (Piperaceae) was found to have hepatoprotective effects on D-galactosamine (D-GalN)/lipopolysaccharide-induced liver injury in mice. From the ethyl acetate-soluble fraction, three new amides, piperchabamides E, G, and H, 33 amides, and four aromatic constituents were isolated. Among the isolates, several amide constituents inhibited D-GalN/tumor necrosis factor-alpha (TNF-alpha)-induced death of hepatocytes, and the following structural requirements were suggested: (i) the amide moiety is essential for potent activity; and (ii) the 1,9-decadiene structure between the benzene ring and the amide moiety tended to enhance the activity. Moreover, a principal constituent, piperine, exhibited strong in vivo hepatoprotective effects at doses of 5 and 10 mg/kg, po and its mode of action was suggested to depend on the reduced sensitivity of hepatocytes to TNF-alpha.

Bioactive constituents from Chinese natural medicines. XXXIII. Inhibitors from the seeds of Psoralea corylifolia on production of nitric oxide in lipopolysaccharide-activated macrophages

The methanolic extract from the seeds of Psoralea corylifolia was found to inhibit production of nitric oxide (NO) in lipopolysaccharide-activated mouse peritoneal macrophages. Among the isolated compounds, bavachinin (IC(50)=26 microM), isobavachalcone (17 microM), neobavaisoflavone (ca. 29 microM), corylifol A (ca. 21 microM), and psoralidin (ca. 23 microM) significantly inhibited the accumulation of nitrite (NO(2)(-)) as a marker of production of NO. Bakuchiol, which is mainly contained in the extract, also showed weak activity at 10 microM, but cytotoxic effects were observed more than 30 microM.

Medicinal flowers. XXIV. Chemical structures and hepatoprotective effects of constituents from flowers of Hedychium coronarium

The 80% aqueous acetone extract from the flowers of Hedychium coronarium was found to show a protective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. On the other hand, two new labdane-type diterpene glycosides, coronalactosides I (1) and II (2), and a new labdane-type trinorditerpene, coronadiene (3), were isolated together with 8 known compounds from the extracts, which were obtained with chloroform and 80% aqueous acetone from the flowers of H. coronarium. The structures of new constituents were elucidated on the basis of chemical and physicochemical evidence. In addition, the principal constituents, coronaririn C and 15-hydroxylabda-8(17),11,13-trien-16,15-olide, displayed hepatoprotective effects, which were stronger than that of the hepatoprotective agent, silybin.

Bioactive constituents from Chinese natural medicines. XXXII. aminopeptidase N and aldose reductase inhibitors from Sinocrassula indica: structures of sinocrassosides B(4), B(5), C(1), and D(1)-D(3)

From the methanolic extract of the whole plant of Sinocrassula indica (Crassulaceae), six new flavonol glycosides, sinocrassosides B(4) (1), B(5) (2), C(1) (3), D(1) (4), D(2) (5), and D(3) (6), were isolated together with 30 compounds. The structures of 1-6 were elucidated on the basis of chemical and physicochemical evidence. In addition, several constituents were found to show inhibitory effects on aminopeptidase N and aldose reductase.

Bioactive constituents from Chinese natural medicines. XXVI. Chemical structures and hepatoprotective effects of constituents from roots of Rhodiola sachalinensis

The methanolic extract from the roots of Rhodiola sachalinensis was found to show a protective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the methanolic extract, five new glycosides, two monoterpene glycosides, two flavonol bisdesmosides, and a cyanogenic glycoside, were isolated together with 34 known compounds. The structures of new constituents were elucidated on the basis of chemical and physicochemical evidence. In addition, the principal constituents, sachalosides III and IV, rhodiosin, and trans-caffeic acid, displayed hepatoprotective effects.