M. M. Gupta

Synthesis of chalcone derivatives on steroidal framework and their anticancer activities

Chalcone derivatives on estradiol framework have been synthesized. Some of the derivatives showed potent anticancer activity against some human cancer cell lines. Compounds 9 and 19 showed potent activity against MCF-7, a hormone dependent breast cancer cell line. Chalcone 7 was further modified to the corresponding indanone derivative (19) using the Nazarov reaction, which showed better activity than the parent compound against the MCF-7 breast cancer cell line. Active anticancer derivatives were also evaluated for osmotic hemolysis using the erythrocyte as a model system. It was observed that chalcone derivatives showing cytotoxicity against cancer cell lines did not affect the fragility of erythrocytes and hence may be considered as non-toxic to normal cells.

Wound Induced Tanscriptional Regulation of Benzylisoquinoline Pathway and Characterization of Wound Inducible PsWRKY Transcription Factor from Papaver somniferum

Wounding is required to be made in the walls of the green seed pod of Opium poppy prior exudation of latex. To withstand this kind of trauma plants regulate expression of some metabolites through an induced transcript level. 167 unique wound-inducible ESTs were identified by a repetitive round of cDNA subtraction after 5 hours of wounding in Papaver somniferum seedlings. Further repetitive reverse northern analysis of these ESTs revealed 80 transcripts showing more than two fold induction, validated through semi-quantitative RT-PCR & real time expression analysis. One of the major classified categories among identified ESTs belonged to benzylisoquinoline transcripts. Tissue specific metabolite analysis of benzylisoquinoline alkaloids (BIAs) in response to wounding revealed increased accumulation of narcotine and papaverine. Promoter analysis of seven transcripts of BIAs pathway showed the presence of W-box cis-element with the consensus sequence of TGAC, which is the proposed binding site for WRKY type transcription factors. One of the Wound inducible ‘WRKY’ EST isolated from our subtracted library was made full-length and named as ‘PsWRKY’. Bacterially expressed PsWRKY interacted with the W-box element having consensus sequence TTGACT/C present in the promoter region of BIAs biosynthetic pathway genes. PsWRKY further activated the TYDC promoter in yeast and transiently in tobacco BY2 cells. Preferential expression of PsWRKY in straw and capsule and its interaction with consensus W-box element present in BIAs pathway gene transcripts suggest its possible involvement in the wound induced regulation of BIAs pathway.

A simple, convenient and chemoselective formylation of sterols by Vilsmeier reagent

Vilsmeier reagent (DMF-POCl(3)) was used as an efficient formylating agent. Several sterols having sec-hydroxyl group at 3/17-position have been modified into respective formate esters. The method is simple, mild, chemoselective and provides sec-alcoholic protection in good yields.

Rapid and Sensitive HPLC Method for the Determination of Polyphenols in Various Lichen Species of Himalayan Origin

Abstract A reversed‐phase high performance liquid chromatograph (HPLC) with photodiode array detection method was developed to determine bioactive polyphenolic substances, methyl β‐orcinolcarboxylate (MBO) and ethyl haematommate (EH) in thalli of various lichen species. The MBO and EH were separated by RP‐HPLC (C18 column, 150 mm×4.6 mm, 5 µm) using isocratic elution systems of acetonitrile:water (0.1% acetic acid). Base line separation of the compounds was obtained in less than 20 min. The method was validated for linearity, repeatability, limits of detection (LOD), and limits of quantification (LOQ). Repeatability (inter‐ and intra‐day, n=6) showed less than 1.5% relative standard deviation (RSD). The LOD and LOQ were found to be 5.97 and 15.51 ng for MBO and 42.63 and 69.03 ng for EH, respectively. The validated HPLC method was employed to quantify MBO and EH in eleven lichen species, used in folklore/traditional systems of medicine collected from the Himalayan region of India.

Microbial secondary metabolites ameliorate growth, in planta contents and lignification in Withania somnifera (L.) Dunal

In the present investigation, metabolites of Streptomyces sp. MTN14 and Trichoderma harzianum ThU significantly enhanced biomass yield (3.58 and 3.48 fold respectively) in comparison to the control plants. The secondary metabolites treatments also showed significant augmentation (0.75–2.25 fold) in withanolide A, a plant secondary metabolite. Lignin deposition, total phenolic and flavonoid content in W. somnifera were maximally induced in treatment having T. harzianum metabolites. Also, Trichoderma and Streptomyces metabolites were found much better in invoking in planta contents and antioxidants compared with their live culture treatments. Therefore, identification of new molecular effectors from metabolites of efficient microbes may be used as biopesticide and biofertilizer for commercial production of W. somnifera globally.

Microbial modulation of bacoside A biosynthetic pathway and systemic defense mechanism in Bacopa monnieri under Meloidogyne incognita stress

Plant-associated beneficial microbes have been explored to fulfill the imperative function for plant health. However, their impact on the host secondary metabolite production and nematode disease management remains elusive. Our present work has shown that chitinolytic microbes viz., Chitiniphilus sp. MTN22 and Streptomyces sp. MTN14 singly as well as in combination modulated the biosynthetic pathway of bacoside A and systemic defense mechanism against Meloidogyne incognita in Bacopa monnieri. Interestingly, expression of bacoside biosynthetic pathway genes (3-Hydroxy-3-methylglutaryl coenzyme A reductase, mevalonate diphosphate decarboxylase, and squalene synthase) were upregulated in plants treated with the microbial combination in the presence as well as in absence of M. incognita stress. These microbes not only augmented bacoside A production (1.5 fold) but also strengthened host resistance via enhancement in chlorophyll a, defense enzymes and phenolic compounds like gallic acid, syringic acid, ferulic acid and cinnamic acid. Furthermore, elevated lignification and callose deposition in the microbial combination treated plants corroborate well with the above findings. Overall, the results provide novel insights into the underlying mechanisms of priming by beneficial microbes and underscore their capacity to trigger bacoside A production in B. monnieri under biotic stress.

Augmentation of systemic resistance and secondary metabolites by chitinolytic microbes in Withania somnifera against Meloidogyne incognita

ABSTRACT Ashwagandha (Withania somnifera L. Dunal), a therapeutically imperative herb is known for its useful steroidal lactones (withanolide and withaferin) and acyl steryl glycosides. The plant is a highly susceptible host for the plant parasitic nematode, Meloidogyne incognita. Selected chitinolytic microbes, namely Cellulosimicrobium cellulans MTN13, Flavobacterium johnsoniae MTN 20, Chitiniphilus sp. MTN22 and Streptomyces sp. MTN14, alone and in combination for M. incognita management and enhancement of secondary metabolites in W. somnifera cv. Poshita were evaluated. A significant enhancement in biomass yield (1.9-fold) and disease diminution (2.7-fold) was found in the dual microbial treatment Streptomyces sp. and Chitiniphilus sp. with respect to the untreated inoculated control plants. A significant augmentation (2.7- and 2.0-fold, respectively) in withanolide A and withaferin A was also found in the same treatment. The studies revealed increment of defence variables 1.1- to 1.3-fold and 1.6- to 2.1-fold in single- and dual-microbe treatments, respectively, than the untreated inoculated plants. The stimulation of the phenylpropanoid pathway and phenolics accumulation was the maximum at 5 days post inoculation (dpi), whereas antioxidant enzymes activities were the highest at 7 dpi. The results thus highlight a possible new function of chitinolytic microbes alone and in combinations that can effectively manage M. incognita-induced stress along with enhanced active molecules of W. somnifera.

Chemical composition and bioactivity of Boswellia serrata Roxb. essential oil in relation to geographical variation

Abstract Oleo–gum–resin of Boswellia serrata Roxb. (Burseraceae) was collected from Shivpuri forest situated in northwestern district of Madhya Pradesh, India. The commercial samples were purchased from Mandsaur and Neemuch districts (the major herbal markets of Madhya Pradesh) for comparative study of their essential oils. The average essential oil contents in the commercial Neemuch samples (11.1%) were much better as compared to the wild collection from Shivpuri (6.1%) as well as commercial collection from Mandsaur (6.9%). The commercial samples contained higher percentage of monoterpene hydrocarbons (81.9–88.1%) including α-thujene (61.4–69.8%) as the major compound. The wild habitat contained higher percentage of oxygenated monoterpenoids/benzenoids (15.7%) and sesquiterpenes (19.2%) including α-terpineol (7.8%), terpinyl isobutyrate (5.1%), and eudesmol (11.5%). Further, the antimicrobial activities of these collections showed remarkable variation among the essential oils. On the other hand, wild habitat contained improved percentage of semi-polar compounds (34.9%) which might be responsible for enhanced antibacterial activity. Similarly, the winter collection from Neemuch (BS-N2) showed significant antioxidant activity, whereas the wild habitat did not show any antioxidant activity. The higher percentage of monoterpene hydrocarbons in commercial samples, especially δ-3-carene, α-pinene, and α-thujene, might be responsible for enhanced antifungal and antioxidant activities. The Pearson correlation values justify the bioactivity relationship of the major compounds with different microbial strains. It also justified the interaction among the major individual compounds.

Acacetin 7-O-α-l-rhamnopyranosyl (1–2) β-D-xylopyranoside Elicits Life-span Extension and Stress Resistance in Caenorhabditis elegans

The advancements in the field of gerontology have unraveled the signaling pathways that regulate life span, suggesting that it might be feasible to modulate aging. To this end, we isolated a novel phytomolecule Acacetin 7-O-α-l-rhamnopyranosyl (1-2) β-D-xylopyranoside (ARX) from Premna integrifolia and evaluated its antiaging effects in Caenorhabditis elegans The spectral data analysis revealed the occurrence of a new compound ARX. Out of the three tested pharmacological doses of ARX, viz. 5, 25, and 50 µM, the 25-µM dose was able to extend life span in C. elegans by more than 39%. The present study suggests that ARX affects bacterial metabolism, which in turn leads to dietary restriction (DR)-like effects in the worms. The effect of ARX on worms with mutations (mev-1, eat-2, sir-2.1, skn-1, daf-16, and hsf-1) indicates that ARX-mediated life-span extension involves mechanisms associated with DR and maintenance of cellular redox homeostasis. This study is the first time report on longevity-promoting activity of ARX in C. elegans mediated by stress and DR-regulating genes. This novel phytomolecule can contribute in designing therapeutics for managing aging and age-related diseases.

A MARKER-BASED STABILITY INDICATING HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHIC METHOD FOR VITEX TRIFOLIA

Casticin, chrysoplenol-D, p-hydroxy benzoic acid, and p-methoxy benzoic acid are representative flavonoids and benzoic acid derivatives in Vitex trifolia, a well-known traditional Chinese, as well as ayurvedic medicine, with a wide range of biological activities. In the present paper, the aforementioned four markers were isolated and simultaneously quantified by TLC densitometric method. In the present study, a novel stability-indicating high-performance thin-layer chromatography (HPTLC) method for quantitative determination of the aforementioned four markers has been developed and validated on silica using solvent dichloromethane–methanol–formic acid (9.6:0.4:0.06 v/v/v) in the absorbance mode at 254 nm. The method showed a good linear relationship (r2 = 0.999) in the concentration range 100–2400 ng per band. It was found to be linear, accurate, precise, specific, robust, and stability-indicating and can be applied for quality control and standardization of other multi-component formulations based on Vitex trifolia.