Structural elucidation, modification and characterization of seed gum from Cassia javahikai seeds: A non-traditional source of industrial gums

A water-soluble seed gum was isolated from seed endosperm of Cassia javahikai. The acid-catalyzed fragmentation, methylation, selective enzymatic degradation and periodate oxidation suggested a heteropolymeric structure for the polysaccharide. The polysaccharide was shown to have a linear chain of β(1 → 4) linked d-mannopyranosyls units with side chains of α(1 → 6) d-galactopyranosyl units. Grafting of polyacrylamide onto the gum was performed using K₂S₂O₈/ascorbic acid redox system in presence of Ag⁺ as catalyst at 35 ± 2 °C. The viscosity of the gum solution increased on grafting and the grafted gum was observed to resist biodegradation for more than 256 h. Thermogravimetric analysis revealed that grafted gum was more thermally stable than native gum.     

Anti-cancer effect of Cassia auriculata leaf extract in vitro through cell cycle arrest and induction of apoptosis in human breast and larynx cancer cell lines

The in vitro anti-cancer effect of Cassia auriculata leaf extract (CALE) was evaluated in human breast adenocarcinoma MCF-7 and human larynx carcinoma Hep-2 cell lines. CALE preferentially inhibited the growth of both the cell lines in a dose-dependent manner with IC₅₀ values of 400 and 500 μg for MCF-7 and Hep-2 cells, respectively. The results showed the anti-cancer action is due to nuclear fragmentation and condensation, associated with the appearance of A₀ peak in cell cycle analysis that is indicative of apoptosis. In addition, CALE treated MCF-7 and Hep-2 cells had decreased expression of anti-apoptotic Bcl-2 protein and increased expression of pro-apoptotic Bax protein, eventually leading a decrease in the Bcl-2/Bax ratio. These results demonstrated that CALE inhibits the proliferation of MCF-7 and Hep-2 cells through induction of apoptosis, making CALE a candidate as new anti-cancer drug.     

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.     

Effect of 2,4-dichlorophenoxyacetic acid on the dark- and light-induced pulvinar movements in Cassia fasciculata Michx

2,4-dichlorophenoxyacetic (2,4-D) applied to excised leaves of Cassia fasciculata modified the dark-induced (scotonasty) and light-induced (photonasty) leaflet movements, showing that this compound acts on rapid turgor variation and the concomitant ion migrations, in particular K⁺. 2,4-D inhibited the scotonastic closure in a dose-dependent manner from 10^–8 M to 10^–5 M and promoted the photonastic opening in the same range of concentrations. The compound acted rapidly since a treatment as short as 5 min gave an obvious effect on the motile reaction; however, a lag period of 45–60 min was needed to observe its effect. Although 2,4-D is a weak acid, its greatest physiological efficiency was obtained with pH values close to neutrality. The physiological results are discussed in relation to the chemical properties and the characteristics of transport of the molecule.Abbreviations ABA abscisic acid - 6-BAP 6-benzylaminopurine - 2,4-D 2,4 dichlorophenoxyacetic acid - GA₃ gibberellic acid - HEPES N-[2-hydroxyethyl] piperazine-N-[2-ethanesulphonic acid] - IAA indole-3-acetic acid - NAA 1-naphthaleneacetic acid - MES 2-(N-morpholino)-ethanesulphonic acid     

Possible Host Adaptation as an Evolution Factor of Cowpea aphid‐borne mosaic virus Deduced by Coat Protein Gene Analysis

Cowpea aphid‐borne mosaic virus (CABMV) causes major diseases in cowpea and passion flower plants in Brazil and also in other countries. CABMV has also been isolated from leguminous species including, Cassia hoffmannseggii, Canavalia rosea, Crotalaria juncea and Arachis hypogaea in Brazil. The virus seems to be adapted to two distinct families, the Passifloraceae and Fabaceae. Aiming to identify CABMV and elucidate a possible host adaptation of this virus species, isolates from cowpea, passion flower and C. hoffmannseggii collected in the states of Pernambuco and Rio Grande do Norte were analysed by sequencing the complete coat protein genes. A phylogenetic tree was constructed based on the obtained sequences and those available in public databases. Major Brazilian isolates from passion flower, independently of the geographical distances among them, were grouped in three different clusters. The possible host adaptation was also observed in fabaceous‐infecting CABMV Brazilian isolates. These host adaptations possibly occurred independently within Brazil, so all these clusters belong to a bigger Brazilian cluster. Nevertheless, African passion flower or cowpea‐infecting isolates formed totally different clusters. These results showed that host adaptation could be one factor for CABMV evolution, although geographical isolation is a stronger factor.     

决明胰蛋白酶抑制剂1活性相关残基的定点突变与抑制活性分析

决明胰蛋白酶抑制剂1（CoTI1）属于Kunitz胰蛋白酶抑制剂家族成员,通过序列比对预测Arg86、Leu84和Thr88等3个氨基酸残基可能是CoTI1发挥抑制作用的关键残基。通过定点突变的方法将Arg86、Leu84与Thr88残基分别突变为Asp残基,并考察各突变体对胰蛋白酶及棉铃虫等鳞翅目害虫消化酶的抑制作用。与CoTI1相比,CoTI1^R86D、CoTI1^T88D与CoTI1^L84D突变体对胰蛋白酶的抑制活性分别下降了93%、64%与59%;对棉铃虫、甜菜夜蛾、斜纹夜蛾等3种鳞翅目害虫消化酶的平均抑制活性分别下降了88.7%、57%与60.7%。以上结果表明Arg86、Leu84与Thr88是CoTI1发挥抑制作用的关键残基,这为CoTI1的抑制分子机制及抗虫研究提供了重要的理论依据。     

剔除灌草和添加翅荚决明对厚荚相思林土壤温室气体排放的影响

森林土壤是CO₂、CH₄和N₂O等温室气体的主要排放源.本研究采用静态箱/色谱分析技术,对中国科学院鹤山丘陵综合开放试验站内厚荚相思林土壤CO₂、CH₄和N₂O通量进行原位测定,研究剔除林下灌草和添加翅荚决明对土壤温室气体排放的影响.结果表明：厚荚相思林土壤CO₂通量在湿季维持较高水平,在旱季则明显降低.CH₄和N₂O在9-11月波动幅度较大,峰值出现在10月.在不同处理下,厚荚相思林土壤可能是CH₄的源也可能是CH₄的汇,而于CO₂和N₂O则是源.林下剔除灌草能显著增大土壤CO₂排放(P<0.05),而添加翅荚决明能加快土壤CH₄的排放(P<0.05).林下剔除灌草及添加翅荚决明两种处理都能够加大N₂O的排放通量.表层土壤温度、湿度、NO₃^--N和微生物生物量碳都是影响土壤温室气体排放的重要因子.     

Cyclotrisiloxan and β-Sitosterol rich Cassia alata (L.) flower inhibit HT-115 human colon cancer cell growth via mitochondrial dependent apoptotic stimulation

Cancer traits dependent chemo and radiotherapy display acute toxicity and long-term side effects. Since last two decades, researchers investigated a new anticancer agents derived from plants. Cassia alata (L.) is a medicinal herb distributed in the tropical and humid regions. In this study, C. alata flower methanol extract (CME) have been prepared using cold percolation method and the phytochemical components were identified using GC–MS analysis. CME have been used to study the antiproliferative and apoptosis properties against human colon cancer HT-115 colon cancer cells, its molecular mechanism have been explored. 0.2 mg/mL dose of CME, inhibited 50% of HT-115 colon cancer cell growth after 48hr was confirmed the significant antiproliferation effect. In normal cells such as Vero cells and hMSCs, 0.2 mg/mL dose of CME shown only 4% and 5% growth inhibition confirmed the HT-115 cell specific cytotoxic effect. This effect might be due to the availability of phytoactive biomolecules in CME such as, cyclotrisiloxan, beta-sitosterol and alpha-tocopherol have been confirmed by GC–MS. Most interestingly, PI and AO/ErBr staining of CME treated HT-115 cells shown early (25%), pro (17%) and late (8%) apoptotic and 3% necrotic cells after 48 hr. Treatment with CME extract showed potential effect on the inhibition of protumorigenic inflammatory and oxidative stress genes. Protumorigenic COX-2/PGE-2 and TNF-α/NF-κB immune axis were normalized after CME treatment. Amounts of both apoptosis related mRNA p53, Bax, caspase 3 and p21 genes were upregulated, whereas it resulted in significant reduction in the anti-apoptotic marker mdm2 and Bcl-2 genes. In conclusion, bioactive compounds present in CME potentially inhibit HT-115 colon cancer cell proliferation via an inhibition of protumorigenic immune axis and stimulation of mitochondria dependent apoptotic pathway without necrotic effect.     

Insecticidal and antifungal potentials of a proteinaceous extract of Cassia occidentalis (Linn.) seeds

Proteinaceous extract obtained from Cassia occidentalis seeds with purification fold of 3.91 and 82.7% of bovine trypsin inhibitory activity was assessed at different concentrations (25, 50, 100, 200, 400 and 800 μg/ml) against Spodoptera litura. Assay of larval feeding suggested proteinaceous extract to be toxic as prepupal (80.16%) and pupal mortalities (100%) along with growth deterrent effect with only 16.71% pupation was observed at 800 μg/ml. Fifty per cent mortality (LC₅₀) was observed at 132.91 μg/ml. Also the inhibitor affected fecundity, longevity and percentage of egg hatching. Nutritional indices were adversely affected as both efficiency of conversion of ingested and digested food decreased while approximate digestibility and metabolic cost increased. In vitro studies on proteolytic enzymes of S. litura revealed inhibition of trypsin and chymotrypsin in lumen and faecal matter at all tested concentrations. Also proteinaceous extract inhibited mycelial growth in Fusarium oxysporum, Alternaria brassicicola and Alternaria alternata at 100 μg/ml.     

Potential hepatoprotective activity of ononitol monohydrate isolated from Cassia tora L. on carbon tetrachloride induced hepatotoxicity in wistar rats

Ononitol monohydrate, structurally similar to glycoside was isolated from Cassia tora L. leaves. Fifty Male rats were divided into five groups. Group I served as normal control. Group II, III and IV rats were induced hepatotoxicity by CCl₄ administering single dose of CCl₄ on 8th day only. Group III was treated with ononitol monohydrate (20 mg/kg body weight) and group IV was treated with reference drug silymarin (20 mg/kg body weight) both dissolved in corn oil and administering for 8 days. Ononitol monohydrate with corn oil alone was given for 8 days (group V). At the end of the experimental period all the animals were sacrificed and analyzed for biochemical parameters to assess the effect of ononitol monohydrate treatment in CCl₄ induced hepatotoxicity. In in vivo study, ononitol monohydrate decreased the levels of serum transaminase, lipid peroxidation and TNF-α but increased the levels of antioxidant and hepatic glutathione enzyme activities. Compared with reference drug silymarin ononitol monohydrate possessesed high hepatoprotective activity. Histopathological results also suggested the hepatoprotective activity of ononitol monohydrate with no adverse effect. Hence we conclude that ononitol monohydrate is a potent hepatoprotective agent.