Diterpene glycosides from Egletes viscosa

A phytochemical investigation of the CHCl (3)-soluble extract of the entire plant of Egletes viscosa (Asteraceae), collected in Peru, afforded two new labdane glycosides, 13-hydroxy-7-oxolabda-8,14-diene 13( R)- O-alpha- L-arabinopyranoside and 13-hydroxylabda-7,14-diene 13( R)- O-alpha- L-arabinopyranoside, along with four known compounds. The structures of the new compounds were elucidated by spectroscopic and chemical methods.     

Gastroprotective mechanisms of centipedic acid, a natural diterpene from Egletes viscosa LESS

This study was aimed to clarify the mechanisms of gastroprotection by centipedic acid (CPA), a natural diterpene from Egletes viscosa LESS. (Asteraceae) using ethanol-induced gastric mucosal damage in mice and gastric secretion in 4-h pylorus-ligated rats as model systems. In mice, intragastrically administered CPA (25, 50, 100 mg/kg) greatly reduced the mucosal lesions induced by 96% ethanol (0.2 ml, p.o.) by 18, 53, and 79%, respectively, whereas N-acetylcysteine (NAC, 300 mg/kg, i.p.), the reference compound produced a 50% inhibition. In 4-h pylorus-ligated rats, CPA (50 mg/kg) applied intraduodenally decreased both gastric secretory volume and total acidity. Similar to NAC, the plant diterpene effectively prevented the ethanol associated decrease in non-proteic sulfhydryls (NP-SH) and the elevated thiobarbituric acid-reactive substances (TBARS) in gastric tissue, suggesting that these compounds exert an antioxidant effect. Pretreatment of mice with indomethacin, the cyclooxygenase inhibitor but not with capsazepine, the transient receptor potential vanilloid-1 (TRPV1)-receptor antagonist greatly suppressed the gastroprotective effect of CPA. Furthermore, CPA gastroprotection was significantly attenuated in mice pretreated with L-NAME or glibenclamide the respective inhibitors of nitric oxide synthase and K(+)(ATP) channel activation. These data suggest that CPA affords gastroprotection by different and complementary mechanisms, which include a sparing effect on NP-SH reserve, and roles for endogenous prostaglandins, nitric oxide, and TRPV1-receptor and K(+)(ATP) channel activation.     

Functional saponins in tea flower (flower buds of Camellia sinensis): gastroprotective and hypoglycemic effects of floratheasaponins and qualitative and quantitative analysis using HPLC

As a part of our characterization studies on the bioactive saponin constituents of tea flowers (Camellia sinensis, flower buds), the methanolic extract and 1-butanol-soluble portion (the saponin fraction) from the flower buds were found to exhibit potent inhibitory effects on ethanol- and indomethacin-induced gastric mucosal lesions in rats and on serum glucose elevation in sucrose-loaded rats. Among the constituents of the 1-butanol-soluble portion, floratheasaponins A, B, and C showed gastroprotective and hypoglycemic activities. Furthermore, we have developed qualitative and quantitative methods using HPLC for the principle saponins, floratheasaponins A-F, in tea flowers, which were previously found to show antiallergic and antiobesity effects. Using those methods, the saponin composition of Indian tea flowers were found to be similar to those of Chinese (Anhui) but not of Japanese tea flowers. On the other hand, it was found that the floratheasaponin contents in tea flowers varied markedly during the blooming period, and they were abundant at half-bloom. Additionally, the contents of caffeine in the tea flowers were examined using HPLC.     

Sesquiterpene components from the flower buds ofMagnolia fargesii

From the Chinese crude drugshin-i, the flower buds ofMagnolia fargesii, four sesquiterpene, oplopanone (1), oplodiol (2), homalomenol A (3) and 1β,4β,7α-trihydroxyeudesmane (4) were isolated. These structures were elucidated and the¹³C-NMR chemical, shifts of these compounds were revised by means of various 2D-NMR techniques.     

Antioxidative effects of quercetin-glycosides isolated from the flower buds of Tussilago farfara L.

A bioassay-guided fractionation of the ethylacetate soluble fraction from the flower buds of Tussilago farfara L. (Compositae) yielded two flavonoids, quercetin 3-O-beta-L-arabinopyranoside and quercetin 3-O-beta-D-glucopyranoside. These two sugar conjugates of quercetin exhibited higher antioxidative activity than their aglycone, quercetin by NBT superoxide scavenging assay. Moreover, treatment with quercetin 3-O-beta-L-arabinopyranoside significantly increased the total glutathione (GSH) contents and the protein level of gamma-glutamylcysteine ligase (gamma-GCL), a key enzyme required for glutathione (GSH) synthesis in a rat hepatocyte cell line. Subcellular fractionation and reporter gene analysis using antioxidant response element (ARE) construct revealed that quercetin 3-O-beta-L-arabinopyranoside increased the level of nuclear Nrf2 and reporter activity, and that these were associated with the induction of the gamma-GCL gene. After 24 h incubation of cells with quercetin 3-O-beta-L-arabinopyranoside, 23% of the glycoside was converted to its aglycone, quercetin, but gamma-GCL was not induced by 7 microM (23%) quercetin. These results suggest that the two quercetin-glycosides isolated from T. farfara L. have direct antioxidative properties, and that quercetin 3-O-beta-L-arabinopyranoside increases the cellular GSH level by inducing the gamma-GCL gene. These novel effects of quercetin-glycosides are suggestive to underlie the potential putative chemopreventive effects of T. farfara L.     

Allergy-preventive effects of chlorogenic acid and iridoid derivatives from flower buds of Lonicera japonica

Allergy-preventive activity of flower buds of Lonicera japonica THUNB. was found in the 35% EtOH extract (LJ) using an in vivo assay, The assay system uses monitoring of a decrease in blood flow (BF) in the tail vein of mice subjected to sensitization with hen-egg white lysozyme (HEL). Bioassay-guided fractionation of the 35% EtOH extract led to isolation of chlorogenic acid (1) and three known iridoid derivatives, loganin (2), secoxyloganin (3) and sweroside (4), all of which inhibited the BF decrease. This suggested that the flower buds of L. japonica and compounds isolated from them have allergy-preventive properties. The structure-activity relationship of iridoid derivatives, morroniside (5), geniposide (6), asperuloside (7), aucubin (8) and catalpol (9), were also tested using the same bioassay method. Compounds 2-5 and 9 having the sp(3) atom at C-8 showed an allergy-preventive effect, while compounds 6, 7 and 8 having a double bond at C-7, C-8 did not.     

Lignans from the flower buds of Magnolia liliflora Desr

Six new lignans, 1- 6, along with six known compounds were obtained from the flower buds of Magnolia liliflora Desr. The new lignans were elucidated as (1 S*,2 R*,5 S*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (1), (1 R*,2 R*,5 R*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (2), (1 R*,?2 R*,5 R*,6 S*)-2,6-bis (3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (3), (1 R*,2 S*,5 R*,6 R*)-2-(3,4-methylenedioxyphenyl)-6-(3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane ( 4), (7' S*,8 R*,8' R*)-3,5'-dimethoxy-3',4,9'-trihydroxy-7',9-epoxy-8,8'-lignan (5), and (7' R*,8' S*)-3,3',4,5'-tetramethoxy-7-en-7',9-epoxy-8,8'-lignan (6), by the analysis of 1D and 2D-NMR as well as HRESIMS data. The capacity of compound 1 to protect against damages to the DNA of rat lymphocyte cells induced by UV irradiation was assessed by the comet assay. It showed stronger antigenotoxicity than ascorbic acid from 6×10(-3)?mmol·L(-1) to 6×10(-6)?mmol·L(-1).     

Aromatic glycosides from the flower buds of Lonicera japonica

Six new glycosides (1–6) have been isolated from the flower buds of Lonicera japonica. Their structures including the absolute configurations were determined by spectroscopic and chemical methods as ( ? )-2-hydroxy-5-methoxybenzoic acid 2-O-β-d-(6-O-benzoyl)-glucopyranoside (1), ( ? )-4-hydroxy-3,5-dimethoxybenzoic acid 4-O-β-d-(6-O-benzoyl)-glucopyranoside (2), ( ? )-(E)-3,5-dimethoxyphenylpropenoic acid 4-O-β-d-(6-O-benzoyl)-glucopyranoside (3), ( ? )-(7S,8R)-(4-hydroxyphenylglycerol 9-O-β-d-[6-O-(E)-4-hydroxy-3,5-dimethoxyphenylpropenoyl]-glucopyranoside (4), ( ? )-(7S,8R)-(4-hydroxy-3-methoxyphenylglycerol 9-O-β-d-[6-O-(E)-4-hydroxy-3,5-dimethoxyphenylpropenoyl]-glucopyranoside (5), and ( ? )-4-hydroxy-3-methoxyphenol β-d-{6-O-[4-O-(7S,8R)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (6), respectively.     

Sesquiterpenoids and other constituents from the flower buds of Tussilago farfara

One new norsesquiterpenoid, namely tussfarfarin A (1), and four new artifacts resulting from extraction procedure, namely tussfarfarin B (2), 6-(1-ethoxyethyl)-2,2-dimethylchroman-4-ol (3), 5-ethoxymethyl-1H-pyrrole-2-carbaldehyde (4), and 3β-hydroxy-7α-ethoxy-24β-ethylcholest-5-ene (5), along with 18 known compounds, were isolated from the flower buds of Tussilago farfara. Their structures were elucidated by extensive spectroscopic analysis.     

Sesquiterpenoids and other constituents from the flower buds of Tussilago farfara

One new norsesquiterpenoid, namely tussfarfarin A (1), and four new artifacts resulting from extraction procedure, namely tussfarfarin B (2), 6-(1-ethoxyethyl)-2,2-dimethylchroman-4-ol (3), 5-ethoxymethyl-1H-pyrrole-2-carbaldehyde (4), and 3β-hydroxy-7α-ethoxy-24β-ethylcholest-5-ene (5), along with 18 known compounds, were isolated from the flower buds of Tussilago farfara. Their structures were elucidated by extensive spectroscopic analysis.     

Structures of acylated sucroses from the flower buds of Prunus mume

Seven new acylated sucroses, mumeoses P–V, were isolated from the flower buds of Prunus mume, cultivated in Zhejiang province, China. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence. Moreover, mumeoses C, D, and R, were shown to substantially inhibit aldose reductase.     

Structure of constituents isolated from the flower buds of Cananga odorata and their inhibitory effects on aldose reductase

Three new terpenoid derivatives, canangaterpenes IV–VI, were isolated from the flower buds of Cananga odorata, cultivated in Thailand, together with eight known flavonoids. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of the isolated compounds on aldose reductase were also investigated. Several terpenoid derivatives and flavonoids were shown to inhibit aldose reductase.     

Glucosylated caffeoylquinic acid derivatives from the flower buds of Lonicera japonica

Three new glucosylated caffeoylquinic acid isomers (1–3), along with six known compounds, have been isolated from an aqueous extract of the flower buds of Lonicera japonica. Structures of the new compounds were determined by spectroscopic and chemical methods as (−)-4-O-(4-O-β-d-glucopyranosylcaffeoyl)quinic acid (1), (−)-3-O-(4-O-β-d-glucopyranosylcaffeoyl)quinic acid (2), and (−)-5-O-(4-O-β-d-glucopyranosylcaffeoyl)quinic acid (3), respectively. In the preliminary in vitro assays, two known compounds methyl caffeate and 2ʹ-O-methyladenosine showed inhibitory activity against Coxsackie virus B3 with IC₅₀ values of 3.70 μmol/L and 6.41 μmol/L and SI values of 7.8 and 12.1, respectively.KEY WORDS: Flower buds, Lonicera japonica, Caprifoliaceae, Glucosylated caffeoylquinic acid, Coxsackie virus B3     

西洋参花蕾中非皂苷类化学成分

目的研究西洋参花蕾中非皂苷类化学成分。方法应用大孔树脂柱色谱、正相硅胶柱色谱等手段对西洋参花蕾中非皂苷类成分进行分离纯化,并通过1H-NMR、13C-NMR、ESI-MS、HMBC、HMQC等波谱数据鉴定化合物结构。结果分离得到了3个核苷类化合物和1个木脂素类化合物,分别鉴定为脱氧尿苷(2′-deoxyuridine,1)、脱氧胸苷(2′-deoxythymidine,2)、阿糖腺苷(vidarabine,3)和松脂素(pinoresinol,4)。结论化合物1-4均为首次从人参属植物中分离得到。     

Topically applied diterpenoids from Egletes viscosa (Asteraceae) attenuate the dermal inflammation in mouse ear induced by tetradecanoylphorbol 13-acetate- and oxazolone

The diterpene compounds, centipedic acid (CA) and 12-acetoxyhawtriwaic acid lactone (AHAL, tanabalin) isolated from the flower buds of Egletes viscosa LESS. (Asteraceae) were evaluated on acute and chronic models of mouse ear dermatitis. A single topical application of CA (0.125; 0.25 and 0.5 mg/ear) or AHAL (0.125, 0.25, 0.5 mg/ear) immediately before 12-O-tetradecanoylphorbol-13-acetate (TPA, 2.5 mug/ear) caused a dose-related significant inhibition of ear inflammatory edema and influx of polymorphonuclear cells, as evidenced by a decrease in ear thickness and reduced myeloperoxidase (MPO) activity and tumor necrosis factor-alpha (TNF-alpha) in ear tissue homogenates. The maximal obtained inhibition for both ear edema and neutrophil influx were almost similar to that of topically applied dexamethasone (0.05 mg/ear). The extent of inhibitions for the respective treatments of CA (0.5 mg/ear), AHAL (0.5 mg/ear), or dexamethasone (0.05 mg/ear) were in the order of 63%, 61% and 81% for the ear edema, and 90%, 95% and 95% for the neutrophil influx. Also, at similar doses, both diterpenes and dexamethasone effectively inhibited the delayed-type hypersensitivity reaction induced by repeated topical application of 1% oxazolone (OXA, 20 microl/ear), as evidenced by significant decreases in ear thickness and interferon-gamma (INF-gamma) levels in ear tissue. Histopathological analysis revealed a marked decrease in epidermal hyperplasia and neutrophil infiltration in animals pretreated with CA or AHAL, in a manner similar to dexamethasone. These data provide evidence for the anti-dermatitis effect of Egletes viscosa diterpenes, by mechanisms that involve a reduced neutrophil influx and decreased production of inflammatory cytokines, TNF-alpha and IFN-gamma.     

三七花蕾化学成分的分离与鉴定

目的对三七(Panax notoginseng(Burk.)F.H.Chen)花蕾的化学成分进行研究。方法利用体积分数为75%提取、D101大孔吸附树脂柱、硅胶柱、Sephadex LH-20柱色谱等方法分离纯化,根据理化性质和光谱数据确定化合物的结构。结果分离得到6个化合物,分别鉴定为:山奈酚-3-O-β-D-半乳糖(2→1)葡萄糖苷(kaempferol 3-O-(2″-β-D-galactopyranosyl)-β-D-glucopyranoside,1)、槲皮素-3-O-β-D-半乳糖(2→1)葡萄糖苷(quercetin3-O-(2″-β-D-galactopyranosy l)-β-D-g lucopyranoside,2)、鸟嘌呤核苷(guanosine,3)、腺嘌呤核苷(adenosine,4)、β-谷甾醇(-βsitostero l,5)、胡萝卜苷(daucostero l,6)。结论化合物1、2为首次从该植物花蕾中分离得到,化合物3、4为首次从该植物中分离得到。     

Four new N-contained iridoid glycosides from flower buds of Lonicera japonica

Four new N-contained iridoid glycosides, lonijapospiroside A (1), l-phenylalaninosecologanin B (2), l-phenylalaninosecologanin C (3), and dehydroprolinoylloganin A (4), were isolated from the flower buds of Lonicera japonica Thunb. Their structures were established on the basis of UV, IR, MS, and NMR spectral data.     

款冬花的化学成分

目的研究我国中药材规范化种植基地栽培的款冬花的化学成分,为其质量评价提供科学依据。方法用色谱法分离,并用各种谱学方法对化合物的结构进行鉴定。结果从款冬花中分离鉴定了28个化合物,分别为:正二十七烷酸(1)、邻苯二甲酸-双-2-乙基己酯(2)、甲基丁酰-3,14-Z-去氢款冬素酯(3)、甲基丁酰-3,14-E-去氢款冬素酯(4)、款冬酮(5)、邻苯二甲酸二丁酯(6)、3β,16α-二羟基鲍尔烯(7)、异鲍尔烯醇(8)、豆甾醇(9)、β-谷甾醇(10)、2,2-二甲基-6-乙酰基苯骈二氢吡喃酮(11)、正十六烷酸(12)、7β-羟基谷甾醇(13)、7α-羟基谷甾醇(14)、7,14-bisdesacylnotonipetrone(15)、棕榈酸甘油酯(16)、胡萝卜苷(17)、6-羟基-2,6-二甲基庚-2-烯-4-酮(18)、反式阿魏酸(19)、异阿魏酸(20)、反式咖啡酸(21)、α-D-葡萄糖(22)、蔗糖(23)、邻苯二甲酸(24)、对羟基苯甲酸(25)、没食子酸(26)、尿嘧啶核苷(27)和腺嘌呤核苷(28)。结论化合物1,12–16,18和20为首次从本属植物中分离得到。     

12-Acetoxyhawtriwaic acid lactone, a diterpene from Egletes viscosa, attenuates capsaicin-induced ear edema and hindpaw nociception in mice: possible mechanisms

The diterpene, 12-acetoxyhawtriwaic acid lactone (AHAL, tanabalin) isolated from the flower buds of Egletes viscosa Less. (Asteraceae) was evaluated on capsaicin-induced ear edema and hindpaw nociception in mice. AHAL (12.5, 25 and 50 mg/kg, P. O.) significantly attenuated the ear edema response to topically applied capsaicin (250 microg), in a dose-related manner. At similar doses, AHAL also suppressed the nocifensive paw-licking behavior induced by intraplantar injection of capsaicin (1.6 microg). These responses to capsaicin were also greatly inhibited by ruthenium red (3 mg/kg, S. C.), a non-competitive capsaicin receptor (TRPV1) antagonist. The anti-edema effect of AHAL (50 mg/kg) seems unrelated to either blockade of mast cell degranulation or to histamine and serotonin receptor antagonism since AHAL did not modify the paw edema response induced by intraplantar injections of compound 48/80, histamine or serotonin. However, the hindpaw edema induced by substance P and vascular permeability increase induced by intraperitoneal acetic acid were significantly suppressed by AHAL. The antinociceptive effect of AHAL (50 mg/kg) was unaffected by naloxone pretreatment but was significantly antagonized by theophylline and glibenclamide, the respective blockers of adenosine and K(ATP)-channels. AHAL (50 mg/kg, P. O.) did not impair the ambulation or motor coordination of mice in open-field and rota-rod tests. These data suggest that AHAL inhibits acute neurogenic inflammation possibly involving capsaicin-sensitive TRPV1-receptors, endogenous adenosine and ATP-sensitive potassium channels.