Ashok Tiwari

Ashok Tiwari
CSIR-Indian Institute of Chemical Technology · Centre for Natural Products & Traditional Knowledge

Ph.D.

About

153
Publications
35,835
Reads
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3,283
Citations
Additional affiliations
May 2011 - December 2021
Academy of Scientific and Innovative Research (AcSIR)
Position
  • Professor
May 2001 - present
Indian Institute of Chemical Technology
Position
  • Principal Investigator
June 1996 - May 1998
Indian Institute of Technology (Banaras Hindu University) Varanasi
Position
  • Research Associate

Publications

Publications (153)
Article
Marine seaweeds are predominant for nutraceuticals and have been food source since ancient times and are currently being used in Chinese medicines and Japanese traditional medicines. In the present study, the chemical profile analysis of Halimeda gracilis was performed using UPLC-ESI-Q-TOF-MS E analysis and assessed for its anticancer activity. A c...
Article
Semal (Bombax ceiba L.) is a tree with sharp thorns, polyadelphous stamens, and a deciduous calyx on the morphological level, and concentric fibrous patches with calcium oxalate rosette crystals on the anatomical level. It is an integral part of many socio-cultural religious ceremonies, rites, rituals, traditions, customs and festivals of native co...
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Calyces of Bombax ceiba (Śālmali, शाल्मली) are used as vegetable by traditional Indian folks. However, scientific investigations for this vegetable are not available in literature. This research presents nutritional and phytochemicals composition in raw calyxes’ powder and antihyperglycemic, antihyperlipidemic, insulin-sensitizing and, antioxidant...
Article
A total of fifty pyrazolines 3a-y and pyrazoles 4a-y have been evaluated for their free-radical scavenging and α-glucosidase inhibitory activities. The pyrazolines 3e, 3h, 3p, 3s and pyrazole 4e have been identified as potent ABTS.+ free-radical scavengers. The thiophene substituted pyrazoline 3s has shown potent ABTS.+ free radical scavenging acti...
Article
Vegetables are considered good food for the management of hyperglycemia. Bombax ceiba L. (family: Bombacaceae) calyces are part of traditional vegetables. This study evaluated its usefulness on various parameters responsible for the development of hyperglycemia and conducted phytometabolomic analysis to identify phytochemicals responsible for the o...
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The global mobility, communication, and dissemination of scientific knowledge are key pillars of modern science. To meet these requirements, a common language of communiqué within the scientific community is required. This is strengthened by English, the working language of laboratories across the world. However, if science has to travel beyond the...
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A series of 1, 2, 3- triazole hybrids (9a-9n) were synthesised from major phenolic constituent, 4-methoxy ethyl cinnamate (5) isolated from rhizomes of Hedychium spicatum (Sm), a traditional medicinal plant used in variety of disease conditions. All the synthesised analogues were tested for their in vitro antiproliferative potential against HCT 116...
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Insulin resistance is associated with obesity and can lead to several metabolic disorders including type II diabetes , nonalcoholic fatty liver disease and cardiovascular problems. Search for the small molecules which can either induce or mimic the insulin action are of great interest and can be utilized to manage insulin resistance. There are seve...
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E)-Methyl/ethyl-3-(2-hydroxyphenyl)acrylates 3a-x have been prepared by the reaction of salicylaldehydes 1a-l with Wittig reagents such as methyl (triphenylphosphoranylidene)acetate 2a and ethyl (triphenylphosphoranylidene)acetate 2b in dry DCM at room temperature. All the synthesized compounds have been evaluated for free-radical scavenging and α-...
Article
Phytometabolomic analysis of Nymphaea nouchali (Burm. F.) boiled rhizome was carried out utilizing UPLC-Q-TOF-MSE, LC-QqQ-MS and GC–MS techniques and evaluated for antihyperglycemic and antioxidative stress potentials. Metabolomic analysis revealed presence of multiple antidiabetic and antioxidant compounds. Boiled rhizome powder exhibited potent a...
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High starch and carbohydrate content in rice (Oryza sativa Linn.) disparages this food responsible for postprandial hyperglycemic excursions. However, rice is an Asian food synonym. Additionally, in traditional Indian healing practices, rice is used for treatment of various disorders. In this research, we analyzed micronutrient and phytochemical co...
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A series of N-(4-aryl-1,3-thiazol-2-yl)-2-(2,4-dioxo-1,3-thiazolidin-5-yl)acetamides 3a-k and N-(1,3-benzothiazol-2-yl)-2-(2,4-dioxo-1,3-thiazolidin-5-yl)acetamides 3l-n are synthesized and evaluated for their α-glucosidase inhibitory activity. N-[4-(m-Chlorophenyl)-1,3-thiazol-2yl]-2-(2,4-dioxo-1,3-thiazolidin-5-yl)acetamide (3g) and N-[4-(o-fluor...
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Claisen-Schmidt condensation of nicotinaldehydes 1a-e with various phenylethanones 2a-d in the presence of base at room temperature have provided chalcones 3a-t. All the synthesized compounds have been evaluated for their anti-microbial, free-radical scavenging and α-glucosidase inhibitory activities. Compounds 3d and 3h have been identified as pot...
Article
Methylglyoxal (MG) is a predominant originator of advanced glycation end products (AGEs). AGEs are complex and heterogeneous compounds, which play a vital role in the development of diabetes-related complications by stimulating oxidative stress and inflammation via acting upon its receptor RAGE. This study examined the effect of Bombax ceiba L. cal...
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Boswellia serrata is a widely used herb in Indian systems of medicine and is well known for its potential medicinal properties. A chromatographic method was developed for the analysis and quantification of six boswellic acid marker compounds, i.e., keto boswellic acid (1), 3-O-Acetyl 11-keto β-boswellic acid (2), ɑ-Boswellic acid (3), β-Boswellic a...
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Nymphaea nouchali (Burm. f.) is known as Neel Kamal, Utpal, Kumud and Indeevar in India. Its tuberous rhizome is used for the preparation of various vegetable items, curries and pickles, and is also consumed boiled or roasted. It finds application in folk medicine for the treatment of a number of disease conditions. In this research macro- and micr...
Article
In continuation of our investigation of pharmacologically-motivated natural products, we have isolated bergenin (1) as a major compound from Mallotus philippensis, which is deployed in different Indian traditional systems of medicine. Here, a series of bergenin-1,2,3-triazole hybrids were synthesized and evaluated for their potentials against a pan...
Article
Bioassay-guided separation of acetone extract from lichen Parmotrema tinctorum (Delise ex Nyl.) Hale led to the isolation of six major phenolic constituents (1–6). Compounds structures were established using NMR and mass spectral techniques. Further, to develop libraries on these scaffolds, a series of semi-synthetic derivatives were prepared (1a–1...
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Considering the importance of ultra-performance liquid chromatography-electrospray ionization-quadrupole time of flight-tandem mass spectrometry (UPLC-ESI-QTOF-MS/MS) hyphenated techniques for analysis of secondary metabolites from crude extracts, the present study was aimed at identification of secondary metabolites in acetone extract of the liche...
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A series of 2H-chromenylphenyloxazolones have been prepared starting from 2H-chromene-3-carbaldehydes. The compounds have been evaluated for their DPPH, ABTS .+ free radical scavenging and α-glucosidase inhibitory activities. Compound 4g has been identified as the most potent ABTS .+ free radical scavenger when compared to the standard drug. The co...
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Consumption of sugar sweetened beverages increase individual’s susceptibility towards weight gain, development of Type 2 diabetes mellitus, hypertension, cardiovascular disorders and number of chronic illnesses. Extended postprandial hyperglycemic rise and larger postprandial glycemic spikes following sugar ingestion in diabetic as well as non-diab...
Article
Background: Sugar-enriched diets/beverages consumption aggravates dysglycemia, dyslipidemia, insulin resistance, glucose intolerance, and weight gain. If unchecked, these disturbances culminate into diabetes. Indian medical classics advise consumption of roasted barley (BR) and roasted horse gram (HG) to resolve such issues. Objective: To investiga...
Article
A one‐pot, facile method has been established for the preparation of 1H‐1,2,3‐triazolyl 1,2‐dihydropyridyl derivatives 6 a‐y. The ring opening of the chromone and cyclo addition are the notable reactions to achieve the target compounds 6 a‐y. All the compounds were screened for their antiproliferative, free radical scavenging (DPPH, ABTS.+), α‐gluc...
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Background: Sugar-enriched diets/beverages consumption aggravates dysglycemia, dyslipidemia, insulin resistance, glucose intolerance, and weight gain. If unchecked, these disturbances culminate into diabetes. Indian medical classics advise consumption of roasted barley (BR) and roasted horse gram (HG) to resolve such issues. Objective: To investiga...
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Full-text available
Tendu, Diospyros melanoxylon Roxb. (Family: Ebenaceae) fruit is indigenous to the Indian subcontinent. The ripe fruit of tendu is eaten by tribal people. Both, unripe, as well as ripe fruits, have been used in folk-medicine by tribal communities. Aqueous methanol extract of unripe fruit displayed potent free radicals scavenging properties and also...
Article
A new series of Schizandrin (1) derivatives were synthesized utilizing the C-9 position of the Schizandrin core and evaluated for their cytotoxic activities against HeLa (cervical cancer), A549 (lung cancer), MCF-7 (breast cancer) and DU-145 (prostate cancer) cell lines. Among the synthesized series, 4e, 4f, 4g and 5 showed potent activities agains...
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Article
A series of nicotinaldehyde based azlactones 3a-g, 6a-f, 11a-d, 16b-c, and 16e-f have been prepared and screened for their free radicals scavenging, a-glucosidase inhibitory and anti-proliferative activities on cell lines, namely lung adenocarcinoma (A549), human breast cancer (MCF7) and human epithelial cervical cancer (HeLa). Compound 3g is the m...
Article
Chromenopyrazolones, tosylchromenopyrazolones and benzoylcoumarins were prepared by the reaction of salicylaldehyde tosylhydrazones with 3-oxobutanoates. The title compounds were screened for their in vitro anti-microbial, DPPH, ABTS.+ free radical scavenging, α-glucosidase inhibitory and anti-inflammatory activities. The bioactivity profile studie...
Article
A comprehensive re-investigation of aerial parts of Caragana sukiensis resulted in the isolation of twelve compounds (1–12) including three new cycloartane type triterpenoids (3–5) respectively. Chemical structures of the isolated compounds were established by analysis of their IR, HRMSESI, 1D and 2D NMR spectroscopic data. In addition, these compo...
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Aqueous methanol extract of seeds and tuber of food and medicinal plant Nymphaea nouchali (Burm.f.) displayed potent pancreatic lipase and intestinal α-glucosidase inhibitory properties. These properties may help reduce development of diet induced postprandial hyperlipidaemia and postprandial hyperglycaemia respectively. In addition, seeds and tube...
Article
Rebaudioside-A is the second most abundant sweet diterpene glycoside (1–3%) present in the leaves of Stevia rebaudiana Bertoni, and is now being considered as a possible sucrose substitute due to its pleasant organoleptic properties and associated health benefits. In the present study, a novel in situ enzymatic transglycosylation of stevioside has...
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ABSTRACT Objective: To examine phytochemical constituents, antihyperglycemic, antihyperlipidemic and free radical scavenging activities in 50% methanol extract of peels of Cucumis melo var. chito (CM), Cucumis pubescens (CP), Lagenaria siceraria (LS), Luffa acutangula (LA), and Momordica charantia (MC) applying in vitro methods. Material and Method...
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Three series of compounds namely ethyl 2-hydroxy-2-(trifluoromethyl)-2H-chromene-3-carboxylates 3a-q, 2H-chromenyl Knoevenagel derivatives 7a-j and 6H-chromenoquinolinones 9a-l have been prepared. The synthesized compounds 3a-q, 7a-j and 9a-g have been screened for anti-oxidant and anti-diabetic activity. Compound 3i shows the most potent ABTS inhi...
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Objective: The objective was to explore the effect of Dosakaya (DK) (Cucumis melo var. chito) juice on sucrose induced dysglycemia and disturbances in antioxidant defense in rats. Materials and methods: Rats were preconditioned with DK juice before administration of sucrose beverage continuously for 1-month. Blood glucose tolerance test and glut...
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Re: Diabetes is rising in OECD countries, report warns Sir, The OECD Health Policy Studies report warns that diabetes is rising in OECD countries and suggests that countries should do more to promote healthier lifestyles to reduce morbidity and mortality related to this disease. In order to combat diseases related to lifestyle, different member cou...
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Re: Health potential of a low glycaemic index diet Sir, The glycaemic index (GI) was developed in 1981 to rank foods according to their glycaemic effect, and later, in 1997, another term, glycaemic load (GL), was introduced to quantify overall glycaemic effect of a food. From a scientific view point, these understandings and developments have subst...
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Re: Tax processed food to subsidise healthier options and tackle obesity, says think tank The opinion expressed by the members of the think tank on international development and humanitarian issues at the Overseas Development Institute, that processed food should be heavily taxed to tackle global problem of obesity epidemic, addrsses one side of t...
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Effect of aqueous methanol extract of different colour sweet bell peppers (Capsicum annuum L.) on parameters of diabesity and carbonyl stress was analysed in vitro. Yellow pepper displayed significantly (p < 0.001) higher intestinal α-glucosidase inhibitory activity than green and red pepper. Porcine pancreatic lipase inhibitory activity was signif...
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Free radicals scavenging and advanced glycation end-products (AGEs) inhibitory potentials in crude chloroform extract of Schisandra grandiflora were evaluated. Bioassay-guided isolation of the chloroform extract led to the identification of 24 compounds. Among the isolates, ( ± ) gomisin M1, arisantetralone C and D, macelignan, saurulignan B and SZ...
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Among the synthesized compounds, derivatives (IIIg)—(IIIi) show potential cytotoxic activities towards several human cancer cell lines.
Article
Re: More children showing early signs of serious diabetes complications, audit finds The growing epidemic of type 2 diabetes and increasing incidence of people being diagnosed with diabetic complications is not only the case now in developed countries such as England and Wales, but it has also spread its tentacles into many parts of the developing...
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The effect of microwave cooking on vegetables was analysed regarding parameters affecting postprandial glycaemic overload and oxidative stress. Microwave cooking affected the biological activities in different vegetables different ways. Rat intestinal α-glucosidase inhibitory activity was not affected by cooking in yellow cucumber, ridge gourd, rad...
Article
The aim was to study and identify free radicals scavenging and antihyperglycemic principles in fruit of Piper attenuatum. Bioassay guided identification of extracts possessing potent free radical scavenging activity, and isolation of compounds was done. Chloroform extract of P. attenuatum possessing potent radical scavenging activity was also evalu...
Article
A series of novel chalcone-triazole derivatives were synthesized and screened for in vitro anticancer activity on the human cancer cell lines IMR32 (neuroblastoma), HepG2 (hepatoma) and MCF-7 (breast adenocarcinoma), DU-145 (prostate carcinoma), and A549 (lung adenocarcinoma). Among the tested compounds, 4r showed the most promising anticancer acti...
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Re: Facts are few, comment is free Yes ! When it comes to comment, there are a number of geniuses, but when it comes to bell the cat, people look aside. Anyway, common people hardly care about all this and move on ahead. Competing interests: No competing interests
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Vegetables have been part of human food since prehistoric times and are considered nutritionally necessary and good for health. Vegetables are rich natural resource of biological antioxidants and possess capabilities of maintaining glucose homeostasis. When taken before starch-rich diet, juice also of vegetables such as ridge gourd, bottle gourd, a...
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Objective: Hyperglycemia induced generation of free radicals and consequent development of oxidative stress by polyol pathway is one of the crucial mechanisms stirring up development of diabetic complications. We evaluated influence of ten vegetables’ juice on polyol pathway along with their antioxidant and antioxidative stress potentials. Materia...
Article
Silibinin is reported to possess multiple biological activities. However, its hydrophobic nature limits its bioavailability compromising in vivo biological activities. Nanoparticles-based delivery of such molecules has emerged as new technique to resolve these issues. Bio-degradable, compatible and adhesive nature of chitosan has recently attracted...
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A series of new 4-(substitutedphenyl)-N,N-bis(4-(trifluoromethyl)benzyl)thiazol-2-amines (6a-j) and 4-(4- chlorophenyl)-N,N-bis(4-methoxybenzyl)thiazol-2-amines (7a-j) have been synthesized. All the newly synthesized compounds are characterized by IR, 1H NMR, 13C NMR and mass spectral studies. Compound 6h has shown promising α-glucosidase inhibitor...
Article
A new series of thiazolidinedione derivatives were synthesized and evaluated for in vitro α-glucosidase inhibition and anticancer activities. Compounds 3d, 3e and 3j showed potential α-glucosidase inhibition with IC50 values ranging between 0.1 and 0.3 μg/ml whereas compounds 3i, 3j and 3k have showed better anticancer activity towards human cancer...
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Consumption of green-leafy vegetables is being advocated beneficial for type 2 diabetes mellitus individuals possibly because they are cost effective source of potent biological antioxidants. This research analyzed various phytochemicals, free radicals scavenging antioxidant potentials and starch digesting enzymes inhibitory activities in fresh jui...
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Refined sugar has now become a common sweetener available world over to every strata of the society. Sugar is not only a commodity that has added sweetness in our lives on different festive-occasions, but also a global affordable energy source to vast majority of underprivileged strata of the societies. Ancient Indian physicians have presaged indis...
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Back ground: Pigeon pea (Cajanus cajan L. Millspaugh) is an important food legume. Its seed, root and, leaves have been explored for various medicinal properties. Pigeon pea seed husks constitute major by-product of milling industries and is mainly used as cattle feeds. Aim: To explore antioxidant and antihyperglycemic potential in pigeon pea seed...
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Plants have been used by humans as food and medicine since prehistoric times. However, in the course of modernisation and following the advent of various scientific terms such as functional foods, nutraceuticals, food additives, etc., the texture and matrix of traditional dietary practice has changed. These changes, in turn, have influenced nutriti...
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Pyranochromenone derivatives 3a–d, 6a–j and 2H-chromenones 8a–b were synthesized and screened for their in vitro α-amylase inhibitory and ABTS•+ [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] free radical scavenging activities. Compounds 3a, 3c, and 6d displayed dual function of ABTS•+ radical scavenging as well as α-amylase inhibition. C...
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Aim: Insulin resistance and leptin resistance are hallmarks in common for development of type 2 diabetes mellitus (T2DM) and obesity. Both these conditions are associated with increased activity and expression of Protein-Tyrosine Phosphatase 1β (PTP 1β). Therefore, inhibition of PTP 1β activity or down-regulation of its expression has become an att...