Enhanced reproductive success revealed key strategy for persistence of devastated populations in Himalayan food‐deceptive orchid,Dactylorhiza hatagirea

Anthropogenic disturbances adversely affect populations of rare and endemic plants, resulting in reduction of their population size and performance. Among different plant groups, deceptive terrestrial orchids are vulnerable and possess greater extinction risks because of rarity in occurrence. To understand the response of food‐deceptive terrestrial orchids to disturbances, we selected Dactylorhiza hatagirea as our representative species, which is endemic to Himalaya, and studied its natural populations. This species is rare for being habitat specific, pollination limited and threatened in its natural habitats. We tested the hypothesis that disturbances lead to reduction in population size and plant performance of food‐deceptive terrestrial orchids. For assessing the impact of disturbance, two contrasting groups, heavily devastated (HD) and lightly devastated (LD), were identified on the basis of frequency and intensity of disturbance (harvesting of plant for tubers) by interviewing local people, medicinal plant extractors and shepherds. HD sites, in comparison to LD sites, were found to have smaller population sizes, but showed an increase in plant growth traits (plant height, specific leaf area, leaf N and specific shoot length). Similarly, plants at HD sites were found to have invested less in inflorescence (inflorescence size, inflorescence length, inflorescence length fraction and flowers per length), but despite that showed higher reproductive success. This was a clear indication of enhanced performance of its populations driven by disturbances. Our findings suggested that food‐deceptive species in small populations tend to reduce the probability of population extinction and have the capability to recover rapidly if conserved in time.     

Scavenging of hydroxyl,methoxy, and nitrogen dioxide free radicals by some methylated isoflavones

Free radicals can be scavenged from biological systems by genistein, daidzein, and their methyl derivatives through hydrogen atom transfer (HAT), single-electron transfer (SET), and sequential proton-loss electron-transfer (SPLET) mechanisms. Reactions between these derivatives and the free radicals OH^., OCH₃^., and NO₂^. via the HAT mechanism in the gas phase were studied using the transition state theory within the framework of DFT. Solvation of all the species and complexes involved in the HAT reactions in aqueous media was treated by performing single point energy calculations using the polarizable continuum model (PCM). The SET and SPLET mechanisms for the above reactions were also considered by applying the Marcus theory of electron transfer, and were found to be quite sensitive to geometry and solvation. Therefore, the geometries of all the species involved in the SET and SPLET mechanisms were fully optimized in aqueous media. The calculated barrier energies and rate constants of the HAT-based scavenging reactions showed that the OH group of the B ring in genistein, daidzein, and their methyl derivatives plays a major role in the scavenging of free radicals, and the role of this OH group in the HAT-based free-radical scavenging decreases in the following order: OH^.?>?OCH₃^. > NO₂^.. The SPLET mechanism was found to be an important mechanism in these free-radical scavenging reactions, whereas the SET mechanism was not important in this context.     

N-(4-Hydroxyphenyl)-3,4,5-trimethoxybenzamide derivatives as potential memory enhancers: synthesis,biological evaluation and molecular simulation studies

The present paper describes the synthesis, biological evaluation and molecular simulation studies of a series of N-(4-hydroxyphenyl)-3,4,5-trimethoxybenzamide derivatives with N,N-dialkylaminoethoxy/propoxy moiety as potential memory enhancers with acetylcholinesterase-inhibiting activity having IC₅₀ in low micromolar range (4.0–16.5 μM). All the compounds showed a good degree of agreement between in vivo and in vitro results as most of these derivatives showed dose-dependent increase in percent retention. Compound 10a showed significant % retention of 84.73 ± 4.51 as compared to piracetam (46.88 ± 5.42) at 3 mg kg^?1 and also exhibited a maximal percent inhibition of 97% at 50 μM. Molecular docking, MM-GBSA and molecular simulation studies were performed establishing a correlation between the experimental biology and in silico results. In silico results indicate that all the compounds have better docking scores and predicted binding free energies as compared to cocrystallized ligand with the best potent ligand retaining conserved hydrophobic interactions with residues of catalytic triad (HIS447), catalytic anionic site (CAS) (TRP86, TYR337, PHE338) and peripheral anionic site (PAS) (TYR72, TYR124, TRP286 and TYR341). Root mean square deviation (RMSD = 2.4 Å) and root mean square fluctuations of 10a–AChE complex during simulation proved its stable nature in binding toward acetylcholinesterase. The docked conformation of 10a and other analogs at the binding site have also been simulated with polar and nonpolar interactions interlining the gorge residues from PAS to catalytic triad.     

Degradation of sevin (1-naphthyl-N-methyl carbamate by Achrombacter sp.

Summary A strain of Achromobacter utilized 1-Naphthyl-N-methyl carbamate (Sevin, Carbaryl) as the sole source of carbon in salt medium. Four degradation products of sevin were identified to be 1-naphthol, hydroquinone, catechol and pyruvate. The organism grew on 1-naphthol, hydroquinone and catechol.     

Fine needle aspiration cytologic diagnosis of erythema nodosum leprosum: a case report

BACKGROUND: Erythema nodosum leprosum (ENL), the type 2 lepra reaction occurring in lepromatous or borderline lepromatous leprosy, presents clinically with acute manifestations that compel the patient to seek medical attention. Recognition and timely management of these patients is critical in order to avoid permanent disability. Fine needle aspiration cytology (FNAC) is a simple, effective tool that aids in correct diagnosis and management of ENL. CASE: A 30-year-old woman presented with history of fever, reddening of the face, and multiple raised, reddish, painful swellings of the bilateral forearms and legs for 7 days. One year previously, she was diagnosed and treated for lepromatous leprosy with type 2 reaction. After a thorough clinical examination a diagnosis of ENL was made. FNA smears from the forearm swellings showed pus-like material with intact and degenerated polymorphonuclear leukocytes and many foamy macrophages with strong granular acid-fast bacillus (AFB) positivity. A cytologic diagnosis of ENL was given, which was confirmed on histopathologic examination of skin biopsy. CONCLUSION: Cytologic features such as a large number of intact and degenerated neutrophils with foamy macrophages and strong granular AFB positivity, in an appropriate clinical background, allows a confident diagnosis of ENL.     

Impairment of <Emphasis Type="Italic">ntc</Emphasis>A gene revealed its role in regulating iron homeostasis,ROS production and cellular phenotype under iron deficiency in cyanobacterium <Emphasis Type="Italic">Anabaena</Emphasis> sp. PCC 7120

Iron deficiency ends up into several unavoidable consequences including damaging oxidative stress in cyanobacteria. NtcA is a global nitrogen regulator controls wide range of metabolisms in addition to regulation of nitrogen metabolism. In present communication, NtcA based regulation of iron homeostasis, ROS production and cellular phenotype under iron deficiency in Anabaena 7120 has been investigated. NtcA regulates the concentration dependent iron uptake by controlling the expression of furA gene. NtcA also regulated pigment synthesis and phenotypic alterations in Anabaena 7120. A significant increase in ROS production and corresponding reduction in the activities of antioxidative enzymes (SOD, CAT, APX and GR) in CSE2 mutant strain in contrast to wild type Anabaena 7120 also suggested the possible involvement of NtcA in protection against oxidative stress in iron deficiency. NtcA has no impact on the expression of furB and furC in spite of presence of consensus NtcA binding site (NBS) and ?10 boxes in their promoter. NtcA also regulates the thylakoid arrangement as well as related photosynthetic and respiration rates under iron deficiency in Anabaena 7120. Overall results suggested that NtcA regulates iron acquisition and in turn protect Anabaena cells from the damaging effects of oxidative stress induced under iron deficiency.     

Triazole tethered isatin-coumarin based molecular hybrids as novel antitubulin agents: Design,synthesis, biological investigation and docking studies

In an attempt to develop potent anti-tubulin agents against most dreadful disease cancer, a library of 28 novel triazole tethered isatin-coumarin hybrids were synthesized by click chemistry approach. Synthesized hybrids were characterized and evaluated against a panel of human cancer cell lines viz. THP-1, COLO-205, HCT-116 and PC-3. Biological assay unveiled that, compounds A-1 to A-6, B-1 to B-4 and C-1 to C-3 displayed significant inhibitory potential against THP-1, COLO-205 and HCT-116 cell lines which were more sensitive towards the designed hybrids. PC-3 among these cell lines was found to be almost resistant. Established SAR revealed marked dependence of the cytotoxic activity on the type of substituent on isatin and the length of carbon-bridge connecting isatin moiety with triazole ring. Unsubstituted isatin and two carbon-bridge were found to be crucial for cytotoxicity. Three most potent hybrids (A-1, A-2 and B-1) were further tested for tubulin polymerization inhibition. Among these three compounds, A-1 found to be endowed with most prominent tubulin polymerization inhibition potential with IC₅₀ value of 1.06 µM which was further confirmed by using confocal microscopy. Possible binding interactions between the most potent hybrid molecule A-1 and tubulin were also divulged by molecular modeling studies.