Sudeep Tandon

Demethoxycurcumin and its Semisynthetic Analogues as Antitubercular Agents

Demethoxycurcumin, isolated from the rhizomes of Curcuma longa, was found to possess antitubercular activity against Mycobacterium tuberculosis H (37)Rv strain at 200 microg/mL. Derivatisation of this active principle yielded a potent agent 6, exhibiting considerable activity with a minimum inhibitory concentration (MIC) value of 7.8 microg/mL. H (37)Rv:Mycobacterium tuberculosis H (37)Rv strain MIC:minimum inhibitory concentration.

Baccoside A suppresses epileptic-like seizure/convulsion in Caenorhabditis elegans

The 1 mm long Caenorhabditis elegans is one of the prime research tools to study different human neurodegenerative diseases. We have considered the case in which increase in the surrounding temperature of this multicellular model leads to abnormal bursts of neuronal cells that can be linked to seizure or convulsion. The induction of such seizure/convulsion mechanism was done by gradually increasing the temperature with 1x buffer (100 mM NaCl, 50 mM MgCl(2)) in adult C. elegans. In the present experiment it is demonstrated that Baccoside A can significantly reduce the seizure/convulsion in C. elegans at higher temperatures (26-28+/-1 degrees C). Furthermore, in T-type Ca(2+) channel cca-1 mutant worms, no convulsion was recorded. Our experimental results suggest that plant molecules from Bacopa monnieri may be useful in suppressing the seizure/convulsion in worms.

Structure-activity relationships of monoterpenes and acetyl derivatives against Aedes aegypti (Diptera: Culicidae) larvae.

BACKGROUND Dengue fever virus transmitted by Aedes aegypti causes lethal mortalities of human beings, and, because of the lack of any vaccine, management of this vector, especially with phytochemicals, is essential. In the present investigation, the structure-activity relationship of monoterpenes and their acetyl derivatives was studied to identify structural features that are responsible for mosquitocidal activity. RESULTS Derivatization of monoterpenes (eugenol, geraniol, linalool, L-menthol and terpeniole) followed by structure-activity relationship studies identified all five acetyl derivatives as having enhanced mosquitocidal activity against fourth-instar larvae of Aedes aegypti. Acetylation of the hydroxyl group in general increased activity in comparison with hydroxyl compounds. Based on LC50 values (ppm), the activities could be placed in the following order: eugenyl acetate (50.2) > linalyl acetate (119.7) > terpinyl acetate (287.1) > menthyl acetate (308.4) > geranyl acetate (325.5), as compared with monoterpenoids: eugenol (82.8) > linalool (242.6) > terpineol (331.7) > L-menthol (365.8) > geraniol (415.0). In eugenyl acetate, the presence of an aromatic ring and a side chain with an allylic double bond makes it most effective. CONCLUSION Bioactive functional groups identified in the study may contribute to the understanding of larvicidal activity of acetyl derivatives and may help in the development of ecofriendly mosquito larvicidal compounds.

Chemical Composition of the Essential Oil from Fresh Leaves of Melaleuca leucadendron L. from North India

Abstract Twenty six constituents of the hydrodistilled essential oil obtained from the leaves of Melaleuca leucadendron L. growing in Lucknow region of north India have been analyzed and identified using GC and GC-MS. Major constituents found in leaves are 1,8-cineole (19.9%), β-eudesmol (15.8%) α-eudesmol (11.3%), viridifloral (8.9%) and guaiol (9.0%) respectively.

Pharmacological and phytochemical evaluation of Ocimum sanctum root extracts for its antiinflammatory, analgesic and antipyretic activities

Background: Long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) increases risk of having a range of gastrointestinal problems. Therefore, new anti-inflammatory, analgesic, antipyretic drugs having lesser side effects are being searched all overthe world as alternatives to NSAIDs. Aims: To evaluate the anti-inflammatory, analgesic and antipyretic profile of Ocimum sanctum root extracts. Materials and Methods: Anti-inflammatory profile of hexane (STH), chloroform (STC), ethyl acetate (STE), butanol (STB) and water (STW) extracts of OS was carried out by using carrageenan induced paw edema. STE a most active extract was further validated in dose dependent manner for anti-inflammatory, analgesic and antipyretic activity as well as oral toxicity profile in small laboratory animals. Identification of bioactives flux and chemical signature of most active fraction STE was developed by using the high-performance liquid chromatography fingerprinting. Results: An ethyl acetate fraction (STE) exhibit most potent anti-inflammatory activity followed by STB, STW, STC and STH. Dose response study of STE showed anti-inflammatory, analgesic and anti-pyretic potential in dose-dependent manner without any toxic effect at dose 2000 mg/kg. Chemical fingerprint revealed the presence of flavanoids. Conclusions: The present research revealed that STE possess anti-inflammatory, analgesic and anti-pyretic properties. However, future research is advocated to evaluate the pharmacological properties of isolated bioactive compounds.

Synthesis of 3,5-dihydroxy-7,8-dimethoxy-2-(4-methoxyphenyl)benzopyran-4-one derivatives as anticancer agents

Different alkyl amide (15a-l) and alkyl amine (16a-e) derivatives of 7,8-dimethoxy-3-hydroxy-2-(4-methoxyphenyl)benzopyran-4-one were synthesized and evaluated for their anticancer activity against five different cancer cell lines using SRB assay. Compounds 15e, 15i, 15j and 16a-e showed significant anticancer activity within the range of IC50 2.58-34.86μM. The most promising molecule, 16c, was further analyzed for its effect on cell cycle and apoptosis of estrogen receptor positive cancer cells (MCF-7 cells) which showed that 16c triggered apoptosis in MCF-7 cells and arrested cells population at sub-G0 (apoptotic) and G2M phase. In tubulin polymerization assay, 16c interfered with kinetics of tubulin polymerization.

1-Methyl-4-propan-2-ylbenzene from Thymus vulgaris Attenuates Cholinergic Dysfunction.

Cholinergic dysfunction is manifested in a plethora of neurodegenerative and psychiatric disorders such as Alzheimer’s, Parkinson’s, and Huntington’s diseases. The extent of cholinergic affliction is maximum in Alzheimer’s disease which is a progressive neurodegenerative disorder involving death of cholinergic neurons. To this date, the therapeutic management of cholinergic dysfunction is limited to provide symptomatic relief through the use of acetylcholinesterase (Ache) inhibitors only. The present study elaborates the potential of thyme oil and its individual components in curtailing cholinergic deficits. We found that thyme oil augments neurotransmission by modulating synaptic acetylcholine (Ach) levels and nicotinic acetylcholine receptor activity, being orchestrated through upregulation of genes cho-1, unc-17 and unc-50. Studies on individual components revealed para-cymene (1-methyl-4-propan-2-ylbenzene) as the active component of thyme oil, contributing its effects through upregulation of cho-1, cha-1, unc-17 and unc-50, while downregulating ace-1 and ace-2. Interestingly, thymol and gamma-terpinene which although were devoid of any activity individually, exhibited significantly enhanced synaptic Ach levels and nicotinic acetylcholine receptor (nAchR) responsiveness, when administered in combination. Our findings advocate thyme oil and its constituents as potential candidates for amelioration of cholinergic dysfunction. The study is speculated to make a way for a new line of “phytomolecules-based drugs” from the diverse pool of natural compounds.

Thyme Oil Reduces Biofilm Formation and Impairs Virulence of Xanthomonas oryzae

Xanthomonas oryzae pv. oryzae (Xoo), a common bacterial plant pathogen regulates its virulence and biofilm formation attribute via a chemical method of communication. Disabling this mechanism offers a promising alternative to reduce the virulence and pathogencity of the microorganism. In this study, the effect of thyme (THY) oil on Quorum Sensing mediated synthesis of various virulence factors and biofilm formation was analyzed. Treatment of Xoo with 500 ppm THY oil displayed a significant diminution in swimming, swarming, exopolysaccharide and xanthomonadin secretion. However, no effect was observed on bacterial growth kinetics and metabolic activity of the cells. Results were further authenticated by RT-qPCR as significant reduction in motA, motB, and flgE genes was observed upon THY oil treatment. Similarly, the expression of some extracellular enzyme genes such as endoglucanase, xylanase, cellobiosidase, and polygalacturonase was also found to be significantly reduced. However, biochemical plate assays revealed insignificant effect of 500 ppm THY oil on secretion of protease, cellulase, and lipase enzymes. The rpfF gene known to play a crucial role in the virulence of the phytopathogenic bacteria was also significantly reduced in the THY oil treated Xoo cells. HPTLC analysis further revealed significant reduction in DSF and BDSF signaling molecules when Xoo cells were treated with 500 ppm THY oil. Disease reduction was observed in in vitro agar plate assay as lesion length was reduced in THY oil treated Xoo cells when compared with the alone treatment. GC–MS result revealed thymol as the active and major component of THY oil which showed potential binding with rpfF gene. Application of 75 μM thymol resulted in downregulation of gumC, motA, estA, virulence acvB and pglA along with rpfF. The other genes such as cheD, flgA, cheY, and pilA, were not found to be significantly affected. Overall, the results clearly indicated THY oil and its active component Thymol to be a potential candidate for the development of anti-virulence agent which in future when applied in combination with conventional bactericides might not only help in lowering the dose of bactericides but also be successful in curbing the disease progression in rice.

Essential Oil Composition of Seed and Fruit Coat of Elettaria cardamomum from South India

Abstract Twenty five constituents of the hydrodistilled essential oil obtined separately from the seed and fruit coat of the Elettaria cardamomum accounting for 95.28% and 96.58% of the oil respectively, growing in South India have been analyzed and identified using GC and GC-MS. Major constituents found common in both seed oil and fruit coat oil are limonene (4.05% and 3.82%), 1,8-cineole (15.13% and 23.74%), α-terpineol (4.67% and 5.25%) and α-terpinyl acetate (56.87% and 51.25%) respectively.

A Review on Phytoconstituents and Biological activities of Cuscuta species

The genus Cuscuta belonging to the Cuscutaceae family comprises of about 100-170 species spread around the world. Although several species have been studied for their phytochemical characterization and biological activities but still many species are yet unexplored till date. Cuscuta are parasitic plants generally of yellow, orange, red or rarely green color. The Cuscuta species were reported rich in flavonoid and glycosidic constituents along with alkaloids, fatty acids, fixed oil, minerals, essential oil and others phytomolecules also etc. Flavonoids and other molecules of Cuscuta species were reported for different types of biological activities such as antiproliferative activity, antioxidant activity, anti-inflammatory, hepatoprotective, antimicrobial and anxiolytic activity, while some other flavonoids have exhibited potential antiviral and anticancer especially in ovarian and breast cancer activities. This review is an attempt to compile all the available data for the 24 different of Cuscuta species on the basis of different types of phytochemical constituents and biological studies as above.