A new 1,5-seco grayanotoxin from Rhododendron decorum

A new minor 1,5-seco-5-oxo-grayanotoxin named grayanotoxin XXI (1), together with three known grayanotoxins, grayanotoxins I, IV and VIII, has been isolated from the leaves of Rhododendron decorum (Ericaceae). The structure of the new compound (1) was determined on the basis of spectroscopic data.     

A new ascorbic acid derivative and two new terpenoids from the leaves and twigs of Rhododendron decorum

The phytochemical study of the ethanol extract of the leaves and twigs of Rhododendron decorum afforded a new ascorbic acid derivative (1), a new ionone analogue (2), a new ursane-type triterpenoid glucoside (3), and four known compounds (4?7). The structures were elucidated by spectroscopic analyses, including HRESIMS, 1D, and 2D NMR. The anti-neuroinflammatory activities of the compounds were evaluated by measuring inhibitory effects of LPS-induced NO production in BV2 cells.     

New glycosides from the twigs and leaves of Rhododendron latoucheae

Six new glycosides (1?6), together with three known ones, were isolated from the twigs and leaves of Rhododendron latoucheae. Their structures were elucidated based on the spectroscopic data, including infrared spectrometry, mass spectrometry, and nuclear magnetic resonance experiments, along with Mosher's method. In addition, all compounds were tested their antiviral (herpes simplex virus-1 and influenza A/95-359) activities.     

A new flavonoid glucoside from Rhododendron seniavinii

The leaves of Rhododendron seniavinii Maxim with little phytochemical information are used as folk remedies for the treatment of acute and chronic bronchitis in China. In our pursuing for the biologically active chemical constituents in the leaves, a new flavonoid glycoside 5,7,3′-trimethoxy-quercetin-3-O-β-d-glucopyranoside (1) was isolated from the water extract of its leaves, together with two known compounds 5,7,3′-trimethoxy-quercetin (2) and ovafolinin B-9′-O-β-d-glucopyranoside (3). The structures of the new flavonoid glucoside as well as two known compounds were elucidated by spectroscopic and chemical methods.     

Protective effect of ethyl acetate fraction of Rhododendron arboreum flowers against carbon tetrachloride-induced hepatotoxicity in experimental models

Objective:

To evaluate the hepatoprotective potential of ethyl acetate fraction of Rhododendron arboreum (Family: Ericaceae) in Wistar rats against carbon tetrachloride (CCl₄)-induced liver damage in preventive and curative models.

Materials and Methods:

Fraction at a dose of 100, 200, and 400 mg/kg was administered orally once daily for 14 days in CCl₄-treated groups (II, III, IV, V and VI). The serum levels of glutamic oxaloacetic transaminase (SGOT), glutamate pyruvate transaminase (SGPT), alkaline phosphatase (SALP), γ-glutamyltransferase (γ -GT), and bilirubin were estimated along with activities of glutathione S-transferase (GST), glutathione reductase, hepatic malondialdehyde formation, and glutathione content.

Result and Discussion:

The substantially elevated serum enzymatic activities of SGOT, SGPT, SALP, γ-GT, and bilirubin due to CCl₄ treatment were restored toward normal in a dose-dependent manner. Meanwhile, the decreased activities of GST and glutathione reductase were also restored toward normal. In addition, ethyl acetate fraction also significantly prevented the elevation of hepatic malondialdehyde formation and depletion of reduced glutathione content in the liver of CCl₄-intoxicated rats in a dose-dependent manner. Silymarin used as standard reference also exhibited significant hepatoprotective activity on post-treatment against CCl₄-induced hepatotoxicity in rats. The biochemical observations were supplemented with histopathological examination of rat liver sections. The results of this study strongly indicate that ethyl acetate fraction has a potent hepatoprotective action against CCl₄-induced hepatic damage in rats.     

羊踯躅的化学成分研究

对羊踯躅植物花蕾的化学成分进行研究,应用多种色谱技术进行分离纯化、波谱技术鉴定其结构。从羊踯躅花蕾中分离并鉴定了15个化合物,分别为2E,4Z-脱落酸（1）,2α-羟基齐墩果酸（2）,齐墩果酸（3）,积雪草酸（4）,苯甲基糖苷（5）,邻苯二甲酸二丁酯（6）,β-谷甾醇（7）,牡荆素（8）,槲皮素（9）,硬脂酸（10）,rhodomollein Ⅰ（11）,rhodojaponin Ⅵ（12）,rhodomollein Ⅺ（13）,rhodojaponin Ⅱ（14）,kalmanol（15）。其中,化合物1 10为首次从羊踯躅植物中得到。     

藏药髯花杜鹃花中化学成分的研究

目的 研究藏药髯花杜鹃Rhododendron anthopogon D.Don花中的化学成分.方法 采用95%乙醇提取制备总浸膏,经萃取及柱层析分离,核磁共振鉴定结构.结果 分离得14个已知化合物,分别为三油酸甘油酯、3-羟基-3-苯基丙酰胺、齐墩果酸甲酯、熊果酸、2-羟基-4-甲氧基苯酚、5-甲氧基糠醛、7-羟基香豆素、23-羟基乌苏酸、β-谷甾醇、槲皮素、杨梅素、桃叶珊瑚苷、杨梅素-3'-O-β-D-吡喃木糖苷、金丝桃苷.结论 所有化合物均为首次从该植物花中分离得到.     

Note: A new chromone from Ficus lyrata

A new chromone, named 5,6-dihydroxy-2-methylchromone (FL-2), along with seven known flavonoids, 5-hydroxy-7,3,3′,4′-tetramethoxyflavone (FL-3), 5,4′-dihydroxy-6,7,8-trimethoxyflavone (FL-4), 5,4′-dihydroxy-7,8-dimethoxyflavone (FL-5), 4-methoxychalcone (FL-6), 7,4′-dimethoxyapigenin (FL-7), 5,7,4′-trihydroxy-2′,3′,6′-trimethoxyisoflavone (FL-8?a rare flavonoid), acacetin-7-O-glucoside (FL-9) and acacetin-7-O-neohesperidoside (FL-10), and β-sitosterol-d-glucoside (FL-1) have been isolated from the leaves of Ficus lyrata. Their structures have been established on the basis of chemical and spectral evidence (IR, UV, ¹H NMR, ¹³C NMR and mass spectra).     

Note: A new flavonoside from Leonurus heterophyllus

In a chemical investigation on the flavone composition of Leonurus heterophyllus a new flavonoside has been isolated. By means of physico-chemical evidences and spectral analysis its structure has been established as quercetin-3-O-[3-(4-hydroxy-3,5-dimethoxybenzyl)-α-l-rhamnopyranosyl]-(1→6)-β-d-galactopyranoside (1).     

A novel 1,10-seco withanolide from Physalis peruviana

A novel 1,10-seco withanolide, 1,10-seco withaperuvin C (1), together with four known withanolides, 4β-hydroxywithanolide E (2), visconolide (3), withanolide F (4), and withaphysanolide (5), was isolated from the aerial parts of Physalis peruviana. The structures of compounds 1–5 were determined on the basis of spectroscopic methods including extensive 1D and 2D NMR analysis. In addition, the possible biogenetic relationships among these five withanolides are discussed.     

A new chromone glycoside from <Emphasis Type="Italic">Rhododendron spinuliferum</Emphasis>

A new chromone glycoside, 3,5,7-trihydroxylchromone-3-O-alpha-L-arabinopyranoside (1), together with quercetin (2), (+)-catechin (3), (-)-epi-catechin (4) were isolated from the aerial parts of Rhododendron spinuliferum. The structure of 1 was elucidated on the basis of spectroscopic and 2D-NMR spectral analysis. In addition, 1 exhibited mild inhibitory effect on NO production in LPS-stimulated RAW264.7 cells.     

照山白醇提物对大鼠缺血心肌的保护作用

目的:研究照山白醇提物对异丙肾上腺素( ISO)致大鼠心肌缺血模型的作用.方法:采用大鼠皮下注射ISO造成心肌缺血模型,抽取暴露腹腔大鼠的腹主动脉血,取得其血清进行检测.采用试剂盒方法,测定血清中肌酸激酶(CK)、肌酸激酶MB同工酶(CK-MB)和乳酸脱氢酶(LDH)的活性,及血清中钙、镁、钾、钠的浓度.结果:照山白醇提物可有效抑制心肌缺血大鼠模型血清CK(P ＜0.001)、CK-MB(P ＜0.001)和LDH(P ＜0.001)活性的升高,及血清中钙(P＜0.001)、镁(P＜0.05)、钾(P＜0.05)、钠(P＜0.001)等离子浓度的改变,均具有统计学意义.结论:照山白醇提物可以改变大鼠缺血心肌的理化参数,具有较明显的保护作用.     

Isolation,modification and cytotoxic evaluation of flavonoids from Rhododendron hainanense

Objectives The aim of this study was to search for antitumour activity of flavonoid compounds. The cytotoxic activity of these compounds in vitro was evaluated against the human leukaemia (HL‐60) and human hepatoma (SMMC‐7721) cell lines. Methods Eight natural flavonoids ( 1 – 8 ) were isolated from the aerial parts of Rhododendron hainanense and a series of modified flavonoid derivatives ( 9 – 18 ) were obtained from the natural product matteucinol ( 1 ), using simple synthetic methods. Antitumour inhibitory activity of these flavonoids was assessed using the sulforhodamine B method. Key findings Most of the compounds exhibited good pharmacological activity and the preliminary structure–activity relationships were described. Within the series of flavonoid derivatives in this study, compounds 3 (2,3‐dihydro‐5‐hydroxy‐7‐methoxy‐2‐(4‐methoxyphenyl)‐6,8‐dimethyl‐4H‐1‐benzopyran‐4‐one) and 16 (5‐hydroxy‐7, 4′‐dimethoxy‐6, 8‐dimethylflavan) exhibited strong inhibitory activity against the HL‐60 cell line with IC50 values (the drug concentration that resulted in a 50% reduction in cell viability or inhibition of the biological activity) of 15.2 and 13.2 µm , respectively. Conclusions Renewed attention to flavonoid derivatives revealed the possibility that compounds 3 and 16 could be considered as lead compounds for the development of new antitumour agents. Our results have not only enriched the family of active flavonoids from natural sources, but have encouraged the synthesis of flavonoid analogues for improving cytotoxic activity.     

Note: A new iridoid diglycoside from Clerodendrum chinense

A new iridoid diglucoside, 5-O-β-glucopyranosyl-harpagide, has been isolated from the aerial part of Clerodendrum chinense together with three known iridoid glucosides and six known cyclohexylethanoids. Their structures have been determined by analyses of spectroscopic data.     

Note: A new compound from Rhododendren anthopogonosides maxim

A new compound, (2R)-4-phenyl-2-O-[β-d-xylopyranosyl(1→6)-β-d-glucopyranosyl]butane (1), has been isolated from the aerial parts of Rhododendren anthopogonoides, together with two known compounds, fraxin (2), and lyoniside (3). Their structures were determined by means of physico-chemical evidence and spectral analyses, including UV, IR, HR-FABMS, ¹H and ¹³C NMR, and 2D NMR data.     

Note: A new phytosterone from Achyranthes bidentata Bl.

A new phytosterone named achyranthesterone A (1), along with the three known compounds stachysterone D (2), β-ecdysone (3) and polypodine B (4) have been isolated from the roots of Achyranthes bidentata Bl. The structure of the new compound was determined as 2β,3β,14α,20S,21,22R,25-heptahydroxycholest-7-en-6-one on the basis of physico-chemical properties and spectral methods.     

Note: A new triterpene from Luculia pinciana Hook.

A new triterpene named luculiaoic acid A (1), showing inhibitory activity of a leukaemia cell line, along with eleven known compounds, has been isolated from the ethyl acetate extract of the stems of Luculia pinciana Hook. All the structures were elucidated on the basis of NMR, MS, and IR methods. The activity to inhibit Staphylococcus aureus and Candida albicans of all compounds showed that ursolic acid inhibits the growth of Staphylococcus aureus with an MIC of 0.5?mg?ml^?1 and an MBC of 10?mg?ml^?1, and scopletin inhibits Candida albicans with an MIC of 1?mg?ml^?1 and an MBC of 5?mg?ml^?1.     

Note: Two new compounds from Glycyrrhiza glabra

Two new flavonosides have been isolated from the roots of Glychirriza glabra and identified as 5,8-dihydroxy-flavone-7-O-β-d-glucuronide, glychionide A, and 5-hydroxy-8-methoxyl-flavone-7-O-β-d-glucuronide, glychionide B.     

Note: A new diterpenoid and active stilbenes from Pinus armandii heartwood

8(17),13-Labdadien-16,14-olid-18-oic acid (1), a new diterpenoid, has been isolated from the heartwood of Pinus armandii Francher, along with seven known diterpenoids (2–8) and four known stilbenes (9–12). Their structures have been elucidated by spectral evidence. (E)-3-Hydroxy-5-methoxystilbene (9) showed significant inhibition against white-rot fungi.     

New grayanol diterpenoid and new phenolic glucoside from the flowers of Pieris formosa

A new grayanol diterpenoid, grayanotoxin XXII (1), and a new phenolic glucoside, benzyl 2-hydroxy-4-O-[β-xylopyranosyl(1″ → 6′)-β-glucopyranosyl]-benzoate (2), were isolated from the flowers of Pieris formosa. Their structures were determined on the basis of spectroscopic analysis and chemical methods.