Antioxidant activity and identification of bioactive compounds from leaves of Anthocephalus cadamba by ultra-performance liquid chromatography/electrospray ionization quadrupole time of flight mass spectrometry

Objective:To evaluate the antioxidant potential of different extract/fractions of Anthocephalus cadamba（A.cadamba）（Roxb.） Miq.（Rubiaceae） and study the tentative identification of their active constituents.Methods:The extract/fractions were screened for antioxidant activity using various in vitro assays viz.DPPH assay,ABTS assay,superoxide anion radical scavenging assay, reducing power assay and plasmid DNA nicking assay.Total phenolic content of extract/fractions was determined by colorimetric method.An ultra-performance LC-electrospray-quadrupoletime of flight mass spectrometry method was used to analyse the active constituents of extract/ fractions of A.cadamba.Results:The ethyl acetate fraction was found to be most active fraction in all the assays as compared to other extract/fractions.The IC50 value of ethyl acetate fraction （ETAC fraction） was 21.24μg/mL,1.12μg/mL,9.68μg/mL and S7.81μg/mL in DPPH assay, ABTS assay,reducing power assay and superoxide scavenging assay respectively.All the extract/ fractions also showed the potential to protect the plasmid DNA（pBR322） against the attack of hydroxyl radicals generated by Fenton’s reagent.The bioactive compounds were identified by UPLC-ESI-QTOF-MS,by comparing the mass andλmax with literature values.Conclusions:The potential of the extract/fractions to scavenge different free radicals in different systems indicated that they may be useful therapeutic agents for treating radical-related pathologic damage.

Ameliorative Role of Pre-Sowing Proline Treatment in Coriandrum sativum L.Seedlings under Mercury Toxicity

Heavy metal toxicity is one of the major ecosystem concerns globally in present time and is also responsible for significant threat to agronomic crops.The current work was conducted to investigate the possible ameliorative role of proline in Coriandrum sativum L.seedlings treated with mercury(Hg).The seedlings were exposed to different concentrations of Hg(0,0.1,0.3 and 0.5 mM)for 20 days.The effects of pre-sowing treatment with proline were studied on C.sativum seedlings in terms of pigment(chlorophylls,carotenoids and anthocyanins),malondialdehyde(MDA),antioxidant compound(glutathione,total phenolic compounds,ascorbic acid)and osmolytes(proline,glycine betaine).Additionally,activities of antioxidant enzymes,namely catalase(CAT),superoxide dismutase(SOD),ascorbate peroxidase(APX)and dehydroascorbate reductase(DHAR)were also studied.A strong decline of photosynthetic pigment concentrations was observed in leaves of C.sativum under Hg toxicity.Treatment of seeds with proline reduced the loss of photosynthetic pigments,counteract Hg-triggered oxidative stress,likely preserving the functionality of antioxidant apparatus under Hg stress.The increment of total polyphenols and glycine betaine also contributed in ameliorating Hg toxicity,suggesting the use of exogenous proline as a potential method to enhance the plant tolerance against heavy metal stress.

Thermo-Protective Role of 28-Homobrassinolide in <i>Brassica juncea</i>Plants

The present work was undertaken to study the effects of 28-homobrassinolide on growth, stress markers, antioxidative enzyme [superoxide dismutase (EC 1.15.1.1), guaiacol peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6) ] activities and protein content in 10 days old seedlings of Brassica juncea L. treated with different degrees (4°C, 44°C) of temperature. 28-homobrassinolide at 10-9 M concentration lowered temperature stress. Different degrees of temperature treatment alone decreased the enzyme activities and protein concentration of seedlings. However, pre-sowing treatments of 28-homobrassinolide lowered the temperature stress and enhanced the contents of MDA and proline, activities of enzymes and protein concentration of seedlings.

Pharmacological and analytical aspects of alkannin/shikonin and their derivatives:An update from 2008 to 2022

Alkannin/shikonin(A/S)and their derivatives are naturally occurring naphthoquinones majorly found in Boraginaceae family plants.They are integral constituents of traditional Chinese medicine Zicao(roots of Lithospermum erythrorhizon).In last two decades significant increase in pharmacological investigations on alkannin/shikonin and their derivatives has been reported that resulted in discovery of their novel mechanisms in various diseases and disorders.This review throws light on recently conducted pharmacological investigations on alkannin/shikonin and their derivatives and their outputs.Various analytical aspects are also discussed and brief summary of patent applications on inventions containing alkannin/shikonin and its derivatives is also provided.

Exploring long-term effects of biochar on mitigating methane emissions from paddy soil:a review

Biochar has been reported to mitigate short-term methane(CH4)emissions from paddy soil.Currently,CH4 mitigation by biochar has primarily focused on the abundance and variations of methanogens and methanotrophs,and changes in their activities during methane production and consumption.However,long-term effects of biochar on methane mitigation from paddy soil remain controversial.This review overviewed the existing mechanisms for CH4 mitigation as a result of biochar application.In addition,the two existing opinions on the long-term CH4 mitigation effect upon biochar application were highlighted.Combining the already explored mechanisms of fresh biochar on CH4 mitigation from paddy soil and a novel discovery,the potential mechanisms of biochar on long-term methane emission response were proposed.This review also revealed the uncertain responses of biochar on long-term CH4 mitigation.Therefore,to achieve carbon neutral goal,it is important to further explore the mechanisms of long-term CH4 mitigation under biochar application.