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Biomedical subjects

Yerra Koteswara Rao

Publications and source records attributed to Yerra Koteswara Rao.

16 recordsLinked to original sources
PubMed2006

Biological evaluation of sulfone derivatives as anti-inflammatory and tumor cells growth inhibitory agents.

A variety of sulfone derivatives including three dimethyl arylsulfonyl malonates (1-3), two bis-(arylethenesulfonyl)-vinyl benzenes (4 and 5) and a sulfone triazole (6) were evaluated for their anti-inflammatory as well as tumor cells growth inhibitory activities in vitro. The sulfone derivatives 1, 2, 3 and 6 significantly and dose-dependently inhibited the production of inflammatory mediators such as nitric oxide (NO), and cytokines (tumor necrosis factor (TNF)-alpha and interleukin (IL)-12), in lipopolysaccharide (LPS) and interferon (IFN)-gamma activated murine peritoneal macrophages, without displaying cytotoxicity. The inhibitory mechanism is found through reducing iNOS protein expression. In addition, the derivatives 1-3 significantly arrest mitogen-stimulated spleen cells in G0/G1 stage, whereas compounds 4-6 blocked the same in the G2/M phase. Furthermore, the sulfone derivatives 3 and 6 showed dramatically reduction in the ratio of IFN-gamma to IL-4 production from mitogen-stimulated spleen cells. On the other hand, the novel compounds exhibited interesting cytotoxic activities against a panel of cell lines, particularly, 20 muM of compound 3 showed 50% cytotoxic effect on human hepatoma cell line, but has no effect on normal human peripheral blood mononuclear cells. In conclusion, compound 3 showed interesting anti-inflammatory and tumor cells growth inhibitory functions.

Animals↗
PubMed2006

Antioxidants enhanced production of destruxin E from cultivation of Metarhizium anisopliae.

The effect of antioxidants on the production of an important cyclohexadepsipeptide congener destruxin E (dtx E) was investigated using the entomopathogenic fungus Metarhizium anisopliae F061. In shaker flask cultivations, 0.015% of menadione-enhanced dtx E production of 220.4 mg/l compared to the control cultivation 90.2 mg/l, which was illustrated by stimulation of dtx E biosynthesis through two electron reduction DT-diaphorase processes in cultivation of M. anisopliae. In 5-l stirred-tank bioreactor cultivation with menadione addition and of control pH 4.0, a yield of 454.6 mg/l of dtx E was obtained after 7 days, and was nearly 30 and 15-fold higher than that from no pH control, and controlled pH 2.0 cultivations, respectively. Further cultivation in a 20-l airlift bioreactor, at pH 4.0, dtx E obtained on the 9th day was 406.0 mg/l, which was much higher than the standard cultivation of no pH control yield 203.3 mg/l on the 11th day. Thus, the present study provides useful information for enhancing dtx E production in cultivation.

Antioxidants↗
PubMed2006

Acylated 5,7,2',6'-oxygenated flavone glycosides from Andrographis alata.

Five acylated 5,7,2',6'-oxygenated flavone glycosides along with the known 5,2',6'-trihydroxy-7-methoxyflavone-2'-O-beta-d-glucopyranoside have been isolated from the whole plant of Andrographis alata. The structures of the compounds were established from spectral (mainly 1D and 2D NMR) and chemical studies.

Acylation↗
PubMed2006

Solid phase extraction of Cd, Cu, and Ni from leafy vegetables and plant leaves using amberlite XAD-2 functionalized with 2-hydroxy-acetophenone-thiosemicarbazone (HAPTSC) and determination by inductively coupled plasma atomic emission spectroscopy.

A method for solid phase extraction of trace metals, namely, Cd, Cu, and Ni, using Amberlite XAD-2 functionalized with a new chelating ligand, 2-hydroxy-acetophenone-3-thiosemicarbazone (Amberlite XAD-2-HAPTSC), has been developed. The optimum experimental conditions for the quantitative sorption of three metals, pH, effect of flow rate, concentration of eluent, sorption capacity, kinetics of sorption, and the effect of diverse ions on the sorption of analytes have been investigated. The chelating resin could be reused for more than 20 cycles of sorption-desorption without any significant change (<1.5%). The accuracy of the proposed procedure was evaluated by standard reference materials. The proposed method was applied for the determination of trace metal ions in leafy vegetable samples collected from different sources and medicinal plant leaves.

Acetophenones↗
PubMed2006

New clerodane diterpenoids from the aerial parts of Pulicaria wightiana.

Two new ent-clerodane-type diterpenoids, compounds 1 and 2, were isolated from the aerial parts of Pulicaria wightiana, together with three known constituents. Their structures were established based on spectroscopic data, and their antibacterial activities were evaluated (Table 2).

Anti-Bacterial Agents↗
PubMed2005

Anti-inflammatory activities of constituents isolated from Phyllanthus polyphyllus.

Four compounds, including one benzenoid, 4-O-methylgallic acid (1), together with three arylnaphthalide lignans, namely phyllamyricin C (2), justicidin B (3) and diphyllin (4) were isolated from the whole plants of Phyllanthus polyphyllus L. (Euphorbiaceae). This was the first isolation report of compounds 1-4 from this plant species. The in vitro inhibitory effects of these compounds were evaluated on the production of nitric oxide (NO) and cytokines (tumor necrosis factor (TNF)-alpha and interleukin (IL)-12), from LPS/IFN-gamma activated murine peritoneal macrophages. The results indicated that the 50% inhibition concentration (IC(50)) values of NO production from activated peritoneal macrophages by compounds 1-4 were 100, 25, 12.5 and 50 microM, respectively. In parallel, these dilutions were approximately inhibited in a similar manner to that observed for cytokines (TNF-alpha, and IL-12) production. On the other hand, at 100 microM concentration compounds 3 and 4 showed 50% inhibition of NO production from peritoneal macrophages that had been pre-activated with LPS/IFN-gamma for 24h, whereas compounds 1 and 2 inhibited only about 20 and 10%, respectively. These results support the use of this plant for the treatment of inflammatory diseases in oriental traditional medicine.

Animals↗
PubMed2005

Anti-inflammatory activities of flavonoids isolated from Caesalpinia pulcherrima.

The anti-inflammatory activities of five flavonoids, namely 5,7-dimethoxyflavanone (1), 5,7-dimethoxy-3',4'-methylenedioxyflavanone (2), isobonducellin (3), 2'-hydroxy-2,3,4',6'-tetramethoxychalcone (4) and bonducellin (5), all of them isolated from Caesalpinia pulcherrima L. was studied in lipopolysaccharide (LPS) and interferon (IFN)-gamma activated murine peritoneal macrophages. These five compounds significantly and dose-dependently inhibited the inflammatory mediators; nitric oxide (NO), and cytokines [tumor necrosis factor (TNF)-alpha and interleukin (IL)-12]. According to their inhibitory results, the order of anti-inflammatory potency was compounds 3>5>4>2>1. Furthermore, peritoneal macrophages were pre-activated with LPS/IFN-gamma for 24h, and determined the inhibitory effects of the above-mentioned isolates on the production of NO after a further 24h. The present study supports the use of Caesalpinia pulcherrima for the treatment of inflammatory diseases in traditional medicine. This is the first study on compounds 1-5 about their anti-inflammatory activities.

Animals↗
PubMed2005

Synthesis, growth inhibition, and cell cycle evaluations of novel flavonoid derivatives.

As a continuation of our search for potential new anticancer agents, a series of ten flavonoid derivatives has been synthesized by cyclization of substituted chalcones. Target compounds were evaluated for their biological activity. Among them, compounds 1-4 and 9 displayed a significant growth inhibitory action against a panel of tumor cell lines including Jurkat, PC-3, and Colon 205. On treatment with an equitoxic (IC50) concentration, compounds 1-5 and 7-9 blocked cells in the G2/M phase of the Jurkat cell cycle, whereas compound 6 blocked the same in the G0/G1 phase.

Cell Cycle↗
PubMed2005

Inhibitory effects of flavonol glycosides from Cinnamomum osmophloeum on inflammatory mediators in LPS/IFN-gamma-activated murine macrophages.

Four kaempferol glycosides were isolated from the leaves of Cinnamomum osmophloeum Kaneh, a Taiwan endemic tree. These compounds namely, kaempferitrin (1), kaempferol 3-O-beta-D-glucopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-7-O-alpha-L-rhamnopyranoside (2), kaempferol 3-O-beta-D-apiofuranosyl-(1-->2)-alpha-L-arabinofuranosyl-7-O-alpha-L-rhamnopyranoside (3), and kaempferol 3-O-beta-D-apiofuranosy-(1-->4)-alpha-L-rhamnopyranosyl-7-O-alpha-L-rhamnopyranoside (4). The structure of compound 2 was determined by spectroscopic analyses and acid hydrolysis. The isolates 1-4 were evaluated as inhibitors of some macrophage functions involved in the inflammatory process. These four compounds inhibited lipopolysaccharide (LPS) and interferon (IFN)-gamma-induced nitric oxide (NO), and cytokines [tumor necrosis factor (TNF)-alpha and interleukin (IL)-12] in a dose-dependent manner. The concentration of 50% inhibition (IC(50)) of NO by compounds 1, 3, 4 were 40, 15, 20microM, respectively. In parallel, these concentrations were approximately in a similar manner to that observed for TNF-alpha and IL-12 production. However, compound 2 inhibited NO and cytokines production by 30% at 100microM concentration. On the other hand, compounds 3 and 4 showed no inhibitory effect on the production of NO from macrophages, when inducible NO synthase was already expressed by the stimulation with LPS and IFN-gamma. Taken together, our results provide evidence that isolates of C. osmophloeum possess an anti-inflammatory potential which constitutes a previously unrecognized biological activity.

Animals↗
PubMed2005

Inhibitory effects of the flavonoids isolated from Waltheria indica on the production of NO, TNF-alpha and IL-12 in activated macrophages.

Three flavonoids were isolated from the whole plants of Waltheria indica and biological properties investigated. On the basis of their spectroscopic data, these compounds were identified as (-)-epicatechin, quercetin, and tiliroside. These flavonoids significantly and dose-dependently inhibited the production of the inflammatory mediator nitric oxide (NO), and the cytokines (tumor necrosis factor (TNF)-alpha and interleukin (IL)-12), in lipopolysaccharide (LPS) and interferon (IFN)-gamma activated murine peritoneal macrophages, without displaying cytotoxicity. The order of inhibitory activity was quercetin>tiliroside>(-)-epicatechin. Furthermore, peritoneal macrophages were pre-activated with LPS/IFN-gamma for 24 h, and the inhibitory effects of the above mentioned isolates on the production of NO were determined after a further 24 h, to address the possible mechanisms of their action. The present study supports the use of W. indica for the treatment of inflammatory diseases in traditional medicine.

Animals↗
PubMed2005

Biflavonoids from Cycas beddomei.

Chemical investigation on the constituents of the cones of Cycas beddomei has resulted in the isolation of a new biflavonoid, 2,3-dihydro-4'''-O-methyl amentoflavone, along with 2,3,2'',3''-tetrahydro hinokiflavone, 2,3,2'',3''-tetrahydro amentoflavone, 2,3-dihydro amentoflavone. The last two compounds were not reported earlier from this plant. The structure of the new compound was established by detailed analysis of its spectral (mainly 1D and 2D NMR) data.

Biflavonoids↗
PubMed2004

Differential effects of synthesized 2'-oxygenated chalcone derivatives: modulation of human cell cycle phase distribution.

Ten structurally related 2'-oxygenated chalcone derivatives, bearing either hydroxy and/or methoxy substituents on the A and B rings, were synthesized through Claisen-Schmidt condensation. The synthesis procedure was relatively easy and had an acceptable yield. The in vitro cytotoxicities of these compounds against the human tumor cells such as Jurkat, U937 cells, and normal cells PHA stimulated PBMCs were investigated. Among those, compounds 1 (IC50 = 2.5 microM), 2 (1.7 microM), and 8 (3.2 microM) showed potent inhibitory activity toward Jurkat cell line. In parallel, compounds 1 (6.7 microM), 2 (1.5 microM), and 10 (5.3 microM) showed the highest activity against U937 cell line. However, the chalcones also inhibit the PHA stimulated PBMCs cells, but the IC50 values were relatively high when compared to the tumor cell line values. Studies were also on the effect of synthesized chalcones on the cell cycle phase distribution. In Jurkat cell line, compounds 7 and 9 showed the highest activity and the most striking effect in reduction of the percentage of cells in the S phase, which was associated with an increase of cells in G2/M phase. In U937 cell line, compound 3 increased the proportion of cells in the G0/G1 phase and reduced the proportion in S phase. In contrast, compounds 1, 9, and 10 showed a decrease effect on the percentage of cells in S phase and an increase effect on the percentage of cells in the G2/M phase of the cell cycle. Whereas in the case of PHA stimulated PBMCs, compounds 1, 4, 8, and 10 increased the percentage of cells in G2/M phase, which was associated with a decrease effect in the S phase of the cell cycle.

Antineoplastic Agents↗
PubMed2004

Two new 5-deoxyflavonoids from Calliandra inermis.

Two new 5-deoxyflavonoids, 7,2',3',4'-tetramethoxyflavone (1) and 7,2',3',4'-tetramethoxyflavanone (2) together with a known flavone 7,4'-dimethoxy-3'-hydroxyflavone (3) were isolated from the whole plant of Calliandra inermis. The structures of these new compounds were elucidated by high resolution electron impact mass spectrometry (HR-EI-MS) and 1D and 2D-NMR spectral studies including 1H-1H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY).

Fabaceae↗
PubMed2003

Flavonoids from Andrographis viscosula.

Phytochemical investigation of the whole plant of Andrographis viscosula has led to the isolation of three new 2'-oxygenated flavonoids, (2R)-5-hydroxy-7,2',3'-trimethoxyflavanone (1), 7,2',5'-trimethoxyflavone (2), 5,7,2',3'-tetramethoxyflavone (3), and eight known flavones, 5,7,2'-trimethoxyflavone (4), 5,7,2',4',5'-pentamethoxyflavone (5), echioidinin (6), 5,2',6'-trihydroxy-7-methoxyflavone (7), 5-hydroxy-7,2'-dimethoxyflavone (8), echioidin (9), echioidinin 5-O-glucoside (10), and 5,2',6'-trihydroxy-7-methoxyflavone 2'-O-glucoside (11). The structures of 1-11 were elucidated by physical and spectral methods, including extensive 2D NMR studies. The presence of 2'-oxygenated flavonoids is apparently restricted to Andrographis species in Acanthaceae. Therefore, 2'-oxygenated flavonoids are regarded as chemotaxonomic markers of Andrographis genus in the Acanthaceae family.

Andrographis↗
PubMed2002

Two new 5-deoxyflavones from Albizia odoratissima.

Two new 5-deoxyflavones, 7,8-dimethoxy-3',4'-methylenedioxyflavone (1) and 7,2',4'-trimethoxyflavone (2) together with a known flavone, 7,4'-dimethoxy-3'-hydroxyflavone (3) were isolated from the rootbark of Albizia odoratissima. The structures of these new compounds were elucidated by electrospray ionization mass spectrometry (ESI-MS) and 1D and 2D-NMR spectral studies including (1)H-(1)H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY).

Albizzia↗