beta-Amyrin and alpha-amyrin acetate isolated from the stem bark of Alstonia boonei display profound anti-inflammatory activity

Context: Alstonia boonei De Wild (Apocyanaceae) is used in ethnomedicine for the management of malaria, ulcer, rhematic pain, toothache, and inflammatory disorders.

Objective: To investigate the anti-inflammatory potential of β-amyrin and α-amyrin acetate isolated from the stem bark of Alstonia boonei using animal models.

Materials and methods: Chromatographic purification of the crude methanol extract led to the isolation and structure elucidation of β-amyrin and α-amyrin acetate. Their anti-inflammatory activities were evaluated in rodents using egg albumen-induced paw edema and xylene-induced ear edema models. The gastric ulcerogenic, in vivo leucocyte migration, and RBC membrane stabilization tests were also investigated.

Results: α-Amyrin acetate at 100?mg/kg showed significant (p?p?>?0.01) irritation of the gastric mucosa while significant (p?p?p?Discussion and conclusion: This study generally provided evidence of profound anti-inflammatory activity of β-amyrin and α-amyrin acetate isolated from the Alstonia boonei stem bark.     

杨梅树皮的化学成分研究

目的 对杨梅（Myrica ruba）树皮的化学成分进行研究。方法用色谱法分离，并用波谱法对化合物的结构进行鉴定。结果从杨梅树皮中分离鉴定了6个化合物，其结构分别为杨梅素（myricetin，1）、杨梅苷（myricitrin，2）、taraxerol（3）、myricadoil（4）、myricanol（5）和myricanone（6）。结论首次报道湖南杨梅树皮的化学成分；1为湖南杨梅树皮的主要化学成分，该植物可作为杨梅素的资源植物加以开发利用。     

香椿树皮的化学成分分析

目的：对香椿（Tooma sinensis）树皮的化学成分进行研究。方法：用色谱法分离，并用各种波谱法对化合物的结构进譬鉴定。结果：从香椿树皮中分离鉴定了8个化合物，其结构分别为二十碳酸乙酯（1）、正二十六烷醇（2）、p谷甾醇（3）、槲皮考（4）、槲皮素-3-O-β-D-葡萄糖苷（5）、5，7-二羟基-8-甲氧基黄酮（6）、杨梅素（7）和杨梅苷（8）。结论：首次报道香椿树皮的化字成分，其中化合物1～3，7，8为首次从该植物中分离得到。     

刺五加茎皮化学成分分析

目的:测定刺五加茎皮中丁香苷及总黄酮的含量。方法:采用HPLC法测定丁香苷的含量,三氯化铝-醋酸钠比色法测定总黄酮的含量。结果:刺五加茎皮中丁香苷的含量为0.132%,高于药典规定的0.05%的标准,总黄酮的含量为1.36%。结论:刺五加茎皮中丁香苷以及总黄酮的含量均较高,有较大的应用价值。     

榆树根皮的化学成分（III）

目的研究榆树(Ulmus pumila L.)根皮中的化学成分。方法采用反复硅胶柱色谱法,凝胶柱色谱法,半制备HPLC等进行分离纯化;通过理化常数测定和光谱分析鉴定其化学结构。结果从榆树根皮正丁醇提取物中分离得到了6个化合物,即lyoniside(1)、(+)-lyoniresinol 3α-O-α-L-rh-amnopyranoside(2)、正丁基-O-β-D-吡喃果糖苷(n-butyl-O-β-D-fructopyranoside,3)、正丁基-O-α-D-呋喃果糖苷(n-butyl-O-α-D-fructofuranoside,4)、正丁基-O-β-D-呋喃果糖苷(n-butyl-O-β-D-fructo-furanoside,5)、胡萝卜苷(daucosterol,6)。结论化合物2-5为属内首次分离得到,化合物1为种内首次分离得到。     

李树根皮的粉末显微鉴别研究

目的:为李树根皮的进一步研究开发提供鉴别依据。方法:使用常规的粉末显微鉴别方法。结果:粉末中可见草酸钙方晶和簇晶,方晶众多且较大;导管为网纹导管和具缘纹孔导管;木栓细胞多角形,棕色或无色;纤维众多,成束,偶见晶鞘纤维。结论:以上显微特征可作为李树根皮的生药鉴别依据。     

Chemical constituents from the stem bark of Trewia nudiflora L. and their antioxidant activities

Three new compounds, namely, (+)-dihydrodehydrodiconiferyl alcohol 4- O- beta-(6'- O-galloyl)-glucopyranoside ( 1), 4,4'- O-dimethylellagic acid 3-(2'- O-acetyl)- alpha-rhamnopyranoside ( 2), and ethyl O- beta-(6'-galloyl)-glucopyranoside ( 3), together with eleven known ones, were isolated from the stem bark of Trewia nudiflora. Their structures were elucidated by means of 1D, 2 D NMR and HR-MS analyses. The antioxidant activities of these compounds were evaluated with the DPPH radical-scavenging assay. Compound 1 showed significant antioxidant activity. In addition, compounds 1, 2 and 3 rescued the H (2)O (2)-induced PC12 cell death at 0.4 microM in the MTT assay.     

Chemical composition and anti-inflammatory activity of the volatile fractions from the bark of eight Mexican Bursera species

The volatile fractions from the bark of eight species of Mexican Bursera were obtained using steam distillation and were subjected to tandem GC-MS analysis for identification of the main constituents. The most abundant components of steam volatiles were monoterpenoids from which alpha-terpineol, terpinen-4-ol, alpha-thujene, linalool and limonene were most frequently isolated. A series of sesquiterpenes and long-chain hydrocarbons were isolated and identified from the barks of some of the studied species . Some volatiles were assayed for anti-inflammatory activity using the TPA-induced ear edema bioassay in mice. The volatile fraction from Bursera lancifolia was about half as active as indomethacin.     

Chemical constituents of the essential oil from the bark of Cinnamomum illicioides A. Chev. from Vietnam

The chemical constituents of the hydrodistilled essential oil from the bark of Cinnamomum illicioides A. Chev., Lauraceae, from Vietnam, have been studied by GC and GC–MS. Seventeen monoterpenoids, eugenol, and thirty-six sesquiterpenoids, accounting for 25, 41.2, and 27.9% of the oil, respectively, were identified. Terpinen-4-ol (10.4%), eugenol (41.2%), and -cadinene (5.6%) are the major components of the oil.W.A. König passed away on 19 November 2004.     

HPLC法测定面条树中的鸭脚树叶碱

目的:建立面条树中鸭脚树叶碱的HPLC含量测定法.方法:色谱柱为Thermo Gold C18(250 mm×4.60 mm,5 μm),检测波长为287 nm,流动相为甲醇-水-三乙胺(47:53:0.005,V/V),流速为1.0 ml·min-1,柱温为35℃.结果:鸭脚树叶碱在0.14～14.00 μg范围内呈良好的线性关系,r=0.999 9;平均回收率为96.98%,RSD=0.9%(n=9).结论:该法简便、准确,可用于面条树的质量控制研究.     

垂头菊属植物化学成分及药理活性研究进展

垂头菊属植物有多种药用价值,数种被用做传统藏药,用于止痛,治疗发热、炎症和中风.本属植物所含化学成分众多,主要为倍半萜类、三萜甾体类、苯丙素类、黄酮类和挥发油等.本文通过查阅近年的文献资料,对垂头菊属植物的化学成分、药理活性进行综述,为垂头菊属植物的研究开发和应用提供科学依据.     

Cytotoxic activity of indole alkaloids from Alstonia macrophylla.

Thirteen indole alkaloids isolated from the root bark of Alstonia macrophylla and a semisynthetic bisindole O-acetylmacralstonine have been assessed for cytotoxic activity against two human lung cancer cell lines, MOR-P (adenocarcinoma) and COR-L23 (large cell carcinoma), using the SRB assay. Pronounced cytotoxic activity was exhibited by the bisindoles on both cell lines. This suggests that, in comparison with the corresponding monomeric indoles, at least part of both the ring systems present in the bisindoles is essential for cytotoxic activity. The potent alkaloids were further tested against a human normal cell line (breast fibroblasts) and other human cancer cell lines including StMI1 1a (melanoma), Caki-2 (renal cell carcinoma), MCF7 (breast adenocarcinoma), and LS174T (colon adenocarcinoma). The bisindoles O-acetylmacralstonine, villalstonine and macrocarpamine were found to possess pronounced activity against cancer cell lines with IC50 values in the range of 2-10 microM, with no discernible cell-type selectivity. However, O-acetylmacralstonine displayed discernibly less toxicity against the normal breast fibroblasts.     

Chemical biology in stem cell research

Stem cells are offering a considerable range of prospects to the biomedical research including novel platforms for disease models and drug discovery tools to cell transplantation and regenerative therapies. However, there are several obstacles to overcome to bring these potentials into reality. First, robust methods to maintain stem cells in the pluripotent state should be established and factors that are required to direct stem cell fate into a particular lineage should be elucidated. Second, both allogeneic rejection following transplantation and limited cell availability issues must be circumvented. These challenges are being addressed, at least in part, through the identification of a group of chemicals (small molecules) that possess novel activities on stem cell biology. For example, small molecules can be used both in vitro and/or in vivo as tools to promote proliferation of stem cells (self-renewal), to direct stem cells to a lineage specific patterns (differentiation), or to reprogram somatic cells to a more undifferentiated state (de-differentiation or reprogramming). These molecules, in turn, have provided new insights into the signaling mechanisms that regulate stem cell biology, and may eventually lead to effective therapies in regenerative medicine. In this review, we will introduce recent findings with regards to small molecules and their impact on stem cell self-renewal and differentiation.     

Formulation and Evaluation of Alstonia boonei Stem Bark Powder Tablets

The aim of this work was to formulate Alstonia boonei dried stem bark powder into tablets by wet granulation method using acacia, gelatine and sodium carboxymethyl cellulose as binders at concentrations of 1, 2, 4 and 8% w/w. The phytochemistry of the stem bark of Alstonia boonei was evaluated. The micromeritic properties of the granules prepared were studied. The tablets were evaluated using the necessary official and unofficial tests. The results of the phytochemical analysis showed that alkaloids, tannins, steroids, saponins, glycosides, flavonoids and terpenoids were present while anthroquinones and acidcompounds were absent. Micromeritic studies showed that Alstonia boonei granules had good flowability. The formulated tablets complied with British Pharmacopoeial specification for weight uniformity, hardness (≥5 kgf) and tablet friability (<1%). For disintegration test, tablets formulated with gelatine and acacia at concentrations of 1, 2 and 4% w/w complied with Pharmacopoeial specification. However, tablets formulated with SCMC (1-8% w/w) and 8% w/w of acacia and gelatine failed the disintegration tests (Disintegration time more than 15 min).