Banasri Hazra

• M.Sc., Ph.D.
• Professor at Jadavpur University

Phospholipases are ubiquitously distributed across mammalian, insect, bacterial and fungal species. They play crucial role in lipid metabolic pathways, signalling networks and hence in progression of cancers, inflammation, infection, atherosclerosis and several other pathological conditions. Overexpression on surface of several cancer cells, broad-...

Hepatitis C virus (HCV), a global malady, causes acute and chronic hepatitis leading to permanent liver damage, hepatocellular carcinoma, and death. Modern anti-HCV therapies are efficient, but mostly inaccessible for residents of underdeveloped regions. To innovate more effective treatments at affordable cost, medicinal plant-based products need t...

Study the quality of essential oil extracted from rosemary

Background: The ongoing COVID-19 pandemic has created an alarming situation due to extensive loss of human lives and economy, posing enormous threat to global health security. Till date, no antiviral drug or vaccine against SARS-CoV-2 has reached the market, although a number of clinical trials are under way. The viral 3-chymotrypsin-like cysteine...

A chemo-selective synthesis of optically pure sugar based benzimidazole from reaction of glycal-2-carboxaldehyde and ortho-phenylene diamine by FeCl 3 catalyzed tandem imination, cyclisation followed by green oxidation by aerial O 2 is reported. Some selected tailor-made chiral benzimidazoles were screened for antimicrobial activity against clinica...

Nearly four decades have passed since the human immunodeficiency virus (HIV) was discovered as the causal agent of acquired immune deficiency syndrome (AIDS). Nevertheless, HIV continues to cause substantial morbidity and mortality, posing a formidable challenge to public health scenario all over the world. Globally, 36.9 million people were living...

Treatment of drug resistant protozoa, bacteria, and viruses requires new drugs with alternative chemotypes. Such compounds could be found from Southeast Asian medicinal plants. The present study examines the cytotoxic, antileishmanial, and antiplasmodial effects of 11 ethnopharmacologically important plant species in Malaysia. Chloroform extracts w...

The emergence of multi-drug resistant pathogenic bacteria, coupled with a decline in discovery of new drugs, has gradually steered the world to the doorstep of post-antibiotic era as trivial infections often become untreatable with the existing antibiotics. Therefore, design and development of new therapeutic strategies would be of paramount im...

Protozoan parasites are among the most common causative agents of some of the major tropical diseases occurring in both humans and domestic animals, leading to enormous loss of life and productivity. Leishmaniases are classified as “neglected tropical diseases” with a huge global burden of vector-borne diseases caused by parasites belonging to the...

Cancer stands as one of the most common causes of death worldwide. Allanblackia gabonensis, a widely distributed plant in the Democratic Republic of Congo and Cameroon, is traditionally used as medicinal plant to cure dysenteries, toothaches, cold and to improve virility in men. The present study aims at evaluating the cytotoxicity of the extracts...

Hepatitis C virus (HCV) is a serious global health problem affecting approximately 130-150 million individuals. Presently available direct-acting anti-HCV drugs have higher barriers to resistance and also improved success rate; however, cost concerns limit their utilization, especially in developing countries like India. Therefore, development of a...

Objective: To investigate the seeds of Millettia ferruginea (M. ferruginea) to unravel its antibacterial, antifungal, antitubercular, and antileishmanial potential for the first time. Methods: M. ferruginea seeds were refluxed separately with chloroform, methanol and water to prepare the three extracts, which were tested against the reference strai...

Emergence of worldwide antimicrobial resistance prompted us to study the resistance modifying potential of plant-derived dietary polyphenols, mainly caffeic acid, ellagic acid, epigallocatechin-3-gallate (EGCG) and quercetin. These compounds were studied in logical combination with clinically significant antibiotics (ciprofloxacin/gentamicin/tetrac...

Human leishmaniasis covers a broad spectrum of clinical manifestations ranging from self-healing cutaneous leishmaniasis to severe and lethal visceral leishmaniasis caused among other species by Leishmania major or Leishmania donovani, respectively. Some drug candidates are in clinical trials to substitute current therapies, which are facing emergi...

The chloroform extract of Valeriana wallichii (V. wallichii) rhizomes was investigated to elucidate the structures responsible for reported antileishmanial activity. Besides bornyl caffeate (1, already been reported by us previously), bioassay-guided fractionation resulted in two additional cinnamic acid derivatives 2–3 with moderate leishmanicidal...

Context: The global surge in multidrug-resistant bacteria and the imminence of tuberculosis pandemics necessitate alternative therapeutic approaches to augment the existing medications. Pomegranate, the fruit of Punica granatum Linn. (Punicaceae), widely recognized for potency against a broad spectrum of bacterial pathogens, deserve further investi...

Anticancer activity of diospyrin and its derivatives (1-5) was evaluated against thirteen human cell lines. Compared to diospyrin (1), the acetylamine derivative (4) exhibited increase in cytotoxicity, particularly in HT-29 colon cancer cells, showing GI50 values of 33.90 and 1.96 μM, respectively. Also, enhanced toxicity was observed when cells, p...

Multi-drug resistant Mycobacterium tuberculosis and other bacterial pathogens represent a major threat to human health. In view of the critical need to augment the current drug regime, we have investigated therapeutic potential of five quinonoids, viz. emodin, diospyrin, plumbagin, menadione and thymoquinone, derived from natural products. The anti...

In continuation of our natural and medicinal research programme on tropical rainforest plants, a bioassay guided fractionation of ethanolic extract of leaves of Canarium patentinervium Miq. (Burseraceae Kunth.) led to the isolation of scopoletin (1), scoparone (2), (+)-catechin (3), vomifoliol (4), lioxin (5), and syringic acid (6). All the compoun...

Reactions of C-aryl-N-phenyl-nitrones with dibenzylideneacetone yielded pairs of diastereomeric bis-isoxazolidines in good to moderate yields. Both types of cycloadducts possessed identical regio- and stereo-selectivity. Molecular modeling studies revealed small difference in energy between the two isomers. Less stable isomer was converted to more...

Bioassay-guided fractionation of a chloroform extract of Valeriana wallichii (V. wallichii) rhizomes lead to the isolation and identification of caffeic acid bornyl ester (1) as the active component against Leishmania major (L. major) promastigotes (IC50 = 48.8 µM). To investigate the structure-activity relationship (SAR), a library of compounds ba...

Melodinus sp. a very rare medicinal plant belonging to the family of Apocynaceae. Six different extracts of Melodinus sp. leaves and barks were screened for their in vitro antitumor activities , among the extracts, the bark and leaf chloroform extract showed significant antitumor activities, the most susceptible cell line is the human breast cancer...

Objective: To evaluate antimicrobial activity of Terminalia arjuna (T. arjuna) bark against clinical strains of multi-drug resistant bacteria, and Candida spp. isolated from patients, as well as the corresponding reference strains. Methods: The antimicrobial activity of water, methanol and chloroform extracts of T. arjuna bark were evaluated by a...

World health organization has called for academic research and development of new chemotherapeutic strategies to overcome the emerging resistance and side effects exhibited by the drugs currently used against leishmaniasis. Diospyrin, a bis-naphthoquinone isolated from Diospyros montana Roxb., and its semi-synthetic derivatives, were reported for i...

Nymphaea pubescens Willd. is used as ingredient of ethnic diet and folk medicine in South-East Asia. The water (NPW), methanol (NPM) and chloroform (NPC) extracts of N. pubescens flowers were investigated for NO., O2.- and DPPH radical scavenging and iron chelating activities in vitro. NPW was found to be the most potent free radical scavenger (EC5...

Haematological reference ranges are often influenced by individual variables, such as race, age, gender and dietary habits. In addition, ecological factors such as climate and altitudemight affect the parameters, while variations in instrumentation techniques and laboratory personnel involved also contribute to the measurements. Therefore, the curr...

A methanolic extract of Punica granatum (pomegranate) fruit pericarp (PGME) was tested in combination with ciprofloxacin against extended-spectrum β-lactamase (ESBL) producing Escherichia coli, Klebsiella pneumoniae, and metallo-β-lactamase (MBL) producing Pseudomonas aeruginosa, which were screened for their resistance profile against fluoroquinol...

Diospyrin diethylether (D7), a bisnaphthoquinonoid derivative, exhibited an oxidative stress-dependent apoptosis in several human cancer cells and tumor models. The present study was aimed at evaluation of the increase in cytosolic calcium [Ca 2+ ] c leading to the apoptotic cell death triggered by D7 in MCF7 human breast carcinoma cells. A phospho...

Cryptolepine (5-methyl-10H-indolo [3, 2-b] quinoline), an indoloquinoline alkaloid (1) isolated from a medicinal plant traditionally used in Western Africa for treatment of malaria, has been shown to possess broad spectrum biological activity in addition to its antiplasmodial effect. Here, the antileishmanial properties of 11 synthetic derivatives...

Background: Radioresistance is the major impediment in radiotherapy of many cancers including prostate cancer, necessitating the need to understand the factors contributing to radioresistance in tumor cells. In the present study, the role of cellular redox and redox sensitive transcription factor, Nrf2 in the radiosensitivity of prostate cancer cel...

Diospyrin diethylether (D7), a bisnaphthoquinonoid derivative, exhibited an oxidative stress-dependent apoptosis in several human cancer cells and tumor models. The present study was aimed at evaluation of the increase in cytosolic calcium [Ca(2+)](c) leading to the apoptotic cell death triggered by D7 in MCF7 human breast carcinoma cells. A phosph...

Treatment of cancer often requires exposure to radiation, which has several limitations involving non-specific toxicity toward normal cells, reducing the efficacy of treatment. Efforts are going on to find chemical compounds which would effectively offer protection to the normal tissues after radiation exposure during radiotherapy of cancer. In thi...

Leishmanial diseases, posing a public health problem worldwide, are caused by Leishmania parasites with a dimorphic life cycle alternating between the promastigote and amastigote forms. Promastigotes transmitted by the vector are transformed into amastigotes residing in the host tissue macrophages. Presently, new antiparasitic agents are needed aga...

The aim was to search for anti-inflammatory and anticancer compounds from three medicinal plants, viz. Ventilago madraspatana Gaertn., Rubia cordifolia Linn. and Lantana camara Linn. The NO* scavenging potential of selected plant extracts was determined on LPS/IFN-gamma activated murine peritoneal macrophage cultures, and iNOS and COX-2 expression...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Punica granatum (Punicaceae), a folkloric plant, is well-known for its significant antioxidant, antifungal, antiviral and anticancerous properties. In our laboratory, studies on the fruit peel of P. granatum for antioxidant properties against DPPH, superoxide (O2.-) and nitric oxide (NO.) radicals were undertaken in cell-free systems. Further, the...

Previous studies have demonstrated that diospyrin (1), a quinonoid plant product, can inhibit the growth of Leishmania donovani parasites. Here, several derivatives of 1 were evaluated by the MTT assay and it was observed that the ethanolamine analogue (10) exhibited maximum cytotoxicity [50% inhibitory concentration (IC(50))=2.9 microM] against L....

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Mitochondria and associated oxidative stress have been shown to play critical roles in apoptotic death induced by various stress agents. Previously, we reported the antitumor property of diospyrin (D1), a plant-derived bisnaphthoquinonoid, and its diethylether derivative (D7), which was found to cause apoptotic death in human cancer cell lines. The...

The synthesis and tumor-inhibitory activity of a series of aminonaphthoquinone derivatives of diospyrin, which was isolated from Diospyros montana Roxb., are presented here for the first time. An aminoacetate derivative showed the maximum (approximately 93%) increase in life span in vivo against murine Ehrlich ascites carcinoma (EAC) at a dose of 1...

Radio-resistance in tumor cells and associated escape from apoptotic mechanism is a major problem in clinical cancer radiotherapy. Therefore, as a strategy to enhance the apoptosis, a combination of radiation and tumor-selective cytotoxic agents might improve the efficacy of treatment. Thus, the radiomodifying potential of diospyrin diethylether (D...

Glycoside derivatives of diospyrin (1) were synthesized for the first time, and the cytotoxicity of the novel compounds vis-à-vis their precursors were evaluated against two human cancer cell lines, viz. malignant melanoma (A375) and laryngeal carcinoma (Hep2). The IC(50) values were in the low micromolar range for all the compounds tested, and A37...

The development of radio-resistant tumor cells might be overcome by the use of tumor selective cytotoxic agents in combination with radiation treatment of cancer. Thus, we are exploring the radiomodifying potential of D7, a tumor-inhibitory compound derived from a plant product, diospyrin, in breast carcinoma cells, MCF-7. The present study indicat...

Derivatisation of diospyrin, a bisnaphthoquinonoid isolated from Diospyros montana Roxb., led to the modification of its inhibitory activity, in vitro, towards a murine tumour model, Ehrlich ascites carcinoma (EAC), and two human cancer cell lines, viz., malignant skin melanoma (A375) and epidermoid laryngeal carcinoma (Hep2). Among the novel deriv...

Alkyl ethers (D2 and D7) synthesized from diospyrin (D1), a naphthoquinonoid isolated from Diospyros montana Roxb., were evaluated for cytotoxicity and capacity to generate reactive oxygen species (ROS) in tumour cells. The tumour inhibitory activity of the quinonoids was assessed in vivo against Ehrlich ascites carcinoma (EAC), while cytotoxicity...

Steroidal and non-steroidal antiinflammatory drugs, despite their various side effects, are in great demand worldwide. Alternatively, herbal formulations provide relief to a large percentage of the population suffering from inflammatory diseases. Therefore, such practices need to be rationalized through a mechanistic approach. Thus, four traditiona...

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A new vegetable oil based oil-in-water microemulsion is developed and characterized as a prospective delivery system for in vivo application A particular weight percent composition 5/30/65 (clove oil/Tween-20/water) was selected (V1) from the clear oil-in-water zone of the pseudoternary phase diagram comprising clove oil, polyoxyethylene sorbitan m...

A sensor based on glassy carbon (GC) electrode modified with cobalt tetrasulfonated phthalocyanine (CoTSPc) and a poly-l-lysine (PLL) film is proposed for diospyrin determination in nanomolar concentrations with differential pulse voltammetry (DPV) technique. The modified electrode showed excellent catalytic activity presenting much higher peak cur...

The antibacterial activity of the extracts of Ventilago madraspatana stem-bark, Rubia cordifolia root and Lantana camara root-bark, prepared with solvents of different polarity, was evaluated by the agar-well diffusion method. Twelve bacteria, six each of gram-positive and gram-negative strains, were used in this study. Chloroform and ethanol extra...

Diospyrin, a bisnaphthoquinonoid plant product, shows inhibitory activity against murine tumour in vivo and human cancer cell lines in vitro. Efforts have further been made to obtain synthetic derivatives of diospyrin with the objective of improved therapeutic effects. With the goal to reduce the toxicity towards normal cells and enhance the effica...

Pre-mRNA splicing is an essential step of the expression of most metazoan protein-coding genes, which is often regulated in a cell type-specific or developmental manner. We have demonstrated previously that human DNA topoisomerase I, an extensively studied target for anticancer drugs, also has an intrinsic protein kinase activity that specifically...

Analysis of molecular constituents of traditional Oriental medicines has acquired a fresh perspective in view of a surge in interest in the consumption of herbal prescriptions all over the world. Several of them contain quinonoid compounds, and the long-standing therapeutic applications of these herbs have been vindicated, to some extent, through r...

The interaction of geshoidin, diospyrin and ergothioneine, with heterologously expressed human glutathione transferases (GSTs) was investigated in vitro. Diospyrin and geshoidin inhibited the three GST isoforms tested, with IC50 values in the range 0.1-0.5 microm, whereas ergothioneine had no effect on the GSTs. The predominant mode of inhibition w...

Isocratic reversed-phase liquid chromatography (LC) method was developed using acetonitrile and water for the determination of diospyrin, a pharmacologically important bisnaphthoquinonoid plant-product. The method was validated for precision, accuracy and reproducibility, and was found to be linear over the concentration range of 1-1000 microg/ml;...

Three derivatives and one structural analogue of diospyrin were synthesized and investigated for their inhibitory activity against Mycobacterium tuberculosis employing the rapid radiometric method in vitro. A novel aminoacetate derivative was found to be more active than the parent compound, the MICs being 50 and 100 mg/L, respectively, for a drug-...

The tumour-inhibitory effect of an ethanolic extract of chicory root was studied against Ehrlich ascites carcinoma in mice; significant results were obtained at doses from 300 to 700 mg/kg.

Diospyrin, a bisnaphthoquinonoid natural product, and three synthetic derivatives have been tested for their action in four human cancer cell lines: acute myeloblastic leukemia (HL-60), chronic myelogenic leukemia (K-562), breast adenocarcinoma (MCF-7) and cervical epithelial carcinoma (HeLa). In cells grown in appropriate media several derivatives...

Objective: To evaluate the inhibitory activity of some new derivatives of diospyrin, a plant-derived bisnaphthoquinonoid compound, against the growth of Leishmania major, the causative parasites of cutaneous leishmaniasis. Methods: Diospyrin (I) was isolated from the stem bark of Diospyros montana Roxb., and its derivatives, viz. alkyl ethers (II-I...

Plumbagin, a plant-derived bioactive naphthoquinonoid compound, was converted to a hydroquinonoid derivative, which was studied for its tumour-inhibitory and antileishmanial activities for the first time. A similar chemical transformation was undertaken on an analogous dimeric compound, diospyrin, and its bioassay results were compared with those o...

Atovaquone (also called Mepron, or 566C80) is a napthoquinone used for the treatment of infections caused by pathogens such as Plasmodium spp. and Pneumocystis carinii. The mechanism of action against the malarial parasite is the inhibition of dihydroorotate dehydrogenase (DHOD), a consequence of blocking electron transport by the drug. As an analo...

The naphthoquinone atovaquone is effective againstPlasmodium and Pneumocystis carinii carinii. InPlasmodium, the primary mechanism of drug action is an irreversible binding to the mitochondrial cytochromebc 1 complex as an analog of ubiquinone. Blockage of the electron transport chain ultimately inhibits de novo pyrimidine biosynthesis since dihydr...

Oxidative dimerisation of 2-naphthol and its methyl ether into the respective 1, 1'-dimers was achieved in good yield and excellent purity through a one-step method using ammonium metavanadate and dilute perchloric acid. 1-Naphthol gave a mixture of isomeric dimers, although its methyl ether was converted almost quantitatively into the correspondin...

Diospyrin is a plant product that has significant inhibitory effect on the growth of Leishmania donovani promastigotes. This compound inhibits the catalytic activity of DNA topoisomerase I of the parasite. Like camptothecin, it induces topoisomerase I mediated DNA cleavage in vitro. Treatment of DNA with diospyrin before addition of topoisomerase I...

The antiinflammatory activity of five structurally related binaphthaquinones and plumbagin has been studied using a blood platelet aggregation assay. The results suggest that for maximum activity a free hydroxyl peri to the quinoid ring is important. Antiplatelet activity does not correlate with other previously determined biological activity, such...

Inhibition of tumour promotion by diospyrin, a plant-derived bioactive bisnaphthoquinonoid compound, and its two derivatives was examined by an in vitro assay utilizing the activation of Epstein–Barr virus (EBV) early antigen (EA) expression in EBV- genome- carrying human lymphoblastoid cells. Synthetic modifications of diospyrin resulted in positi...

Diospyrin and its four synthetic derivatives were tested in vitro against intracellular amastigotes of Leishmania donovani and Trypanosoma cruzi in macrophages and extracellular Trypansoma brucei brucei bloodstream form trypomastigotes. Diospyrin was inactive against L. donovani but had ED50 values of 27 and 50 μm, respectively, against T. cruzi an...

Diospyrin, a bisnaphthoquinonoid plant product and its derivatives have shown significant inhibitory activities against murine tumours in vivo. Studies on the haematological status, serum protein and creatinine levels, activities of several serum glycolytic enzymes, and histopathology of the mice inoculated with Ehrlich ascites carcinoma were carri...

Diospyrin, a bisnaphthoquinonoid plant product and its derivatives have shown significant inhibitory activities against murine tumours in vivo. Studies on the haematological status, serum protein and creatinine levels, activities of several serum glycolytic enzymes, and histopathology of the mice inoculated with Ehrlich ascites carcinoma were carri...

Synthesis of derivatives of diospyrin, a natural product, has led to the modification of its tumour-inhibitory effect, in vitro, towards Ehrlich ascites carcinoma and antiparasitic activity against Leishmania donovani in vitro. The present study shows that two of these novel hydroquinoid analogues derived from diospyrin also show enhanced inhibitor...

Sodium (or ammonium) metavanadate in dilute perchloric acid was found to be a suitable reagent for the determination of fructose, mannose, galactose, arabinose, ribose, xylose, sucrose and maltose. A mixture containing the saccharide and an excess of the reagent was refluxed over a small flame for 40 min. The residual metavanadate was determined io...

Ammonium (or sodium) vanadate in dilute perchloric acid was found to be an excellent reagent for the determination of glucose. The method involves refluxing a mixture containing glucose and an excess of vanadate solution in dilute perchloric acid over a small flame for 40 min. To this reaction mixture potassium iodide was added to determine the res...

The aromatic α-hydroxycarboxylic acids (I) react with sodium or ammonium vanadate to perform oxidative decarboxylation, yielding the ketones (II).

Oxidative decarboxylation of the α-hydroxycarboxylic acids (I) to form the ketones (II) is performed using ammonium molybdate.

General background material may be found in our companion article in these Proceedings dealing with other anticancer agents1.