Three new alkaloids from the twigs of Cassia siamea and their bioactivities

Three new tricyclic alkaloid, siamalkaloids A–C (1–3), together with three known alkaloids (3–6) were isolated from the twigs of Cassia siamea. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–6 were tested for their anti-tobacco mosaic virus (anti-TMV) activity, and compound 3 exhibited high anti-TMV activity with inhibition rate of 34.5%. This rate is higher than that of positive control. In addition, the cytotoxicity of compounds 1–6 were also tested, and compounds 2–6 showed weak activity with IC₅₀ values ranging from 2.8 to 9.4 μM for some tested human tumor cell lines.     

Ethanol extract of Cassia siamea L. increases life span in Drosophila melanogaster

The stem of Cassia siamea L. (Fabaceae) has been used in traditional Thai medicine as a longevity remedy. The objective of this study was to investigate the effect of ethanolic stem extract of C. siamea (CSE) on the life span of Drosophila melanogaster. The results showed that a diet containing 10 mg/mL CSE could significantly extend the mean life span of D. melanogaster by 14% compared with the control diet (P < 0.01). The maximum life span was 74, 78, and 84 days in control, CSE (5 mg/mL) and CSE (10 mg/mL) groups, respectively. Supplementation of CSE at 10 mg/mL also significantly increases the activity of superoxide dismutase (SOD) and catalase (CAT) at days 25 and 40 compared with the control diet. Treatment of CSE at 5 and 10 mg/mL significantly increased the climbing ability of D. melanogaster both on days 25 and 40 compared with the control flies. Paraquat and H₂O₂ challenge test showed that flies fed with CSE at 10 mg/mL had a longer survival time than the control flies (P < 0.01). This study provides supportive evidence that supplementation with CSE prolonged life span and reduced oxidative stress in D. melanogaster.     

In-vitro anti-inflammatory activity of serine protease inhibitor from Cassia siamea and Dolichos biflorus: A comparative study

Cassia siamea is a nonedible legume belonging to Fabaceae. The seed of C. siamea contains ~16% of protein. The study reports the biochemical characterization of purified novel serine protease inhibitor from seeds of C. siamea, aimed with assessing the anti-inflammatory activity. The seed extract was subjected to ammonium sulfate precipitation followed by fast protein liquid chromatography (FPLC)-anion exchange chromatography and affinity-chromatography to obtain a relative pure protease inhibitor. Thirty-fivefold purification with the specific activity of 250 U/mg of trypsin inhibitory unit was obtained. The characterization of protease inhibitor for optimum temperature, pH, and metal ions were measured using N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA) assay and casein zymogram. The C. siamea trypsin inhibitor (CsTI) has a relative molecular mass of 25.540 kDa. Purified CsTI and Dolichos biflorus were tested for anti-inflammatory efficacy against A549 and RAW264.7 cell lines. The inhibitory activity of both purified inhibitors are comparable and are potent toward anti-inflammatory activity. The purified inhibitor shows to be a promising candidate as anti-inflammatory agent by targeting the serine proteases.     

Air pollution exacerbates effect of allergenic pollen proteins of Cassia siamea: a preliminary report

Pollinosis caused by several allergenic proteins in pollen grains has been a major problem of healthcare in most parts of the world. Environmental factors such as air pollution are known to alter the release of allergenic pollen proteins from a variety of the plant species. Cassia siamea is commonly planted along roadsides and in industrialised areas in many parts of India. The present study reports the findings of animal experiments demonstrating the effect of air pollution on the allergenicity of Cassia siamea pollen proteins. Total white blood cell (WBC) count and lymphocyte count were significantly higher in animals that received protein extract of pollen collected from a polluted site compared to those that received protein extract of pollen collected from a non-polluted site. This was concomitant with increased production of IgE antibodies; followed by marked degranulation of mast cell leading to heighten type I hypersensitivity in these animals. These results are important for the development of a consensus linking ever-increasing pollution due to industrialisation and an increase in associated pollinosis.     

Chrobisiamone A, a new bischromone from Cassia siamea and a biomimetic transformation of 5-acetonyl-7-hydroxy-2-methylchromone into cassiarin A

A new bischromone, chrobisiamone A (1) with an antiplasmodial activity has been isolated from the leaves of Cassia siamea and the structure was elucidated by 2D NMR analysis. Cyclization of 5-acetonyl-7-hydroxy-2-methylchromone (2) in the presence of ammonium acetate resulted in generation of cassiarin A (3) with an unprecedented tricyclic skeleton, supporting a biogenetic pathway proposed for 3.     

Two chromone glycosides from Cassia multijuga

Two new 2-methylchromone glycosides have been identified in the leaves of Cassia multiluga.     

Anthraquinones from Cassia sophera root bark

Two new anthraquinones have been isolated from the root bark of Cassia sophera and characterized as 1,8-dihydroxy-3,6-dimethoxy-2-methyl-7-vinylanthraquinone and 1,3-dihydroxy-5,7,8-trimethoxy-2-methylanthraquinone.     

神黄豆化学成分研究

对神黄豆Cassia agnes Brenan茎部的化学成分进行了研究。从其甲醇提取物的乙酸乙酯萃取部分分离得到了10个化合物,根据理化性质和波谱数据鉴定其结构分别为:(–)-表阿夫儿茶精(1)、12,13-dihydromicromeric acid(2)、白桦脂醇(3)、8(17),12E,14-labdatrien-19-ol(4)、β-谷甾醇(5)、胡萝卜苷(6)、二十四烷酰单甘油酯(7)、sitoindoside I(8)、9Z,12Z-octadecadienoic acid(9)和间苯三酚(10)。以上化合物均为首次从神黄豆中发现。     

Flavonoid glycosides from Cassia alata.

Two new glycosides, chrysoeriol-7-O-(2"-O-beta-D-mannopyranosyl)-beta-D-allopyranos ide and rhamnetin-3-O-(2"-O-beta-D-mannopyranosyl)-beta-D-allopyranosid e, were isolated from the seeds of Cassia alata. The structures were established on the basis of chemical evidence and spectroscopic methods, especially NMR.     

Two anthraquinone glycosides from Cassia marginata roots

From the roots of Cassia marginata, 1,3-dihydroxy-6,8-dimethoxy-2-methyl anthraquinone 3-O-rhamnosyl-(1 → 6)-glucopyranoside and 1,3,5,8-tetrahydroxy-2-methyl anthraquinone 3-O-glucoside have been isolated and their structures elucidated.     

Structure of a galactomannan from Cassia alata seed

A water-soluble galactomannan, isolated from the seeds of Cassia alata Linn, has been investigated by using methylation analysis, periodate and CrO₃ oxidation, n.m.r. spectroscopy, and reaction with Bandeiraea simplicifolia lectin and an α-d-galactosidase. The polysaccharide is composed of heptasaccharide units joined by β-(1→4) linkages. The polysaccharide has a molecular weight of 26,400, corresponding to ∼23 units.     

Oxanthrone esters from the roots of Cassia kleinii

From the roots of Cassia kleinii two new oxanthrone esters, kleinioxanthrone-3 and kleinioxanthrone-4 have been isolated. Their structures were established as 1,8-dihydroxy-3-methyl-9(10H)-anthracenone-10-oxyhexadecanoate 3 and 2,6,7-trihydroxy-1,8-dimethoxy-3-methyl-9(10H)-anthracenone-10-oxydecanoate 4 respectively based on degradative and spectroscopic evidence.     

Dimeric hydroanthracenes from the unripe seeds of Cassia torosa

From the unripe seeds of Cassia torosa three new dimeric hydroanthracene derivatives were isolated along with stigmasterol, sitosterol, campesterol, physcion-9-anthrone, torosachyrsone and the phlegmacins A₂ and B₂. The structures of the new derivatives were established as physcion-10, 10′-bianthrone, anhydrophlegmacin B₂ [2-(6′-methoxy-3′-methyl-3′, 8′, 9′-trihydroxy-1′-oxo-1′, 2′, 3′, 4′-tetrahydroanthracene-10′-yl)-1, 8-dihydroxy-3-methoxy-6-methyl-9-oxo-9, 10-dihydroanthracene] and torosanin [2-(6′-methoxy-3′-methyl-3′, 8′,9′-trihydroxy-1′-oxo-1′, 2′, 3′,4′-tetrahydroanthracene-5′-yl)-1, 8-dihydroxy-3-methoxy-6-methyl-9-oxo-9, 10-dihydroanthracene], respectively.