Effect of medium, explants, cytokinins and node position on in vitro shoot multiplication of Caralluma lasiantha (Wight) N.E.Br., an endemic and medicinally important plant

An efficient shoot multiplication protocol was developed for Caralluma lasiantha, an endemic medicinal plant belonging to the family Asclepiadaceae. Mature explants were cultured on Murashige and Skoog (MS), (1962) medium, Gamborg's B5 (B5) and woody plant medium (WPM) supplemented with 6-benzyladenine (BA), 8.87 µM, for shoot induction. The nodal explants exhibited maximum shoot sprouting frequency when cultured on MS medium supplemented with BA (8.87 µM). Nodal explants cultured on MS medium supplemented with different concentrations of cytokinins with 3% sucrose exhibited 100% sprouting frequency. Maximum number of three to four shoots was induced from mature second nodal explants on MS medium containing BA (8.87 µM). The isolated microshoots were rooted on half strength MS medium supplemented with naphthalene acetic acid (NAA), 0.54 µM. The plantlets thus developed were hardened and successfully established in soil.Key words: 6-Benzyl adenine, nodal explant, naphthalene acetic acid, Caralluma lasiantha, micro  propagation

Physicochemical, antioxidant and antimicrobial properties of citrus peel essential oils

Essential oils are produced as secondary metabolites of aromatic plants and can be extracted from leaves, seeds or fruit peel of the plants. Citrus peel is a rich source of limonene which is antimicrobial in nature. The present study aimed to deal with the physicochemical, antioxidant and antimicrobial properties of citrus peel essential oil from Citrus reticulate (mandarin orange), Citrus limetta (mosambi) and Citrus limon (lemon).  The lemon peel oil had lower peroxide value (1.6 meq/kg of sample), saponification value (112.2 mg KOH/g of oil) and higher iodine value (116 gI2/100g oil) when compared with orange and mosambi peel essential oil. DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity of citrus peel essential oil was measured  and the result indicated that the total antioxidant activity of lemon peel oil was 89.2 % Radical Scavenging activity (RSA). The antifungal activity was assessed by agar dilution method, whereas the antibacterial property was assessed by the agar diffusion method. Lemon peel oil recorded better antimicrobial properties with minimum inhibitory concentration of 0.3% against Aspergillus flavus MTCC 277, 0.2% for Penicillium  MTCC 1995 and Fusarium oxysporum MTCC 284. Likewise, the minimum inhibitory concentration of lemon peel oil against Staphylococcus aureus MTCC 96 was 0.3%; Salmonella enterica MTCC 733 and Erwinia sp MTCC 2760 was 0.5%; Pseudomonas aeruginosa MTCC 1688 and Escherichia coli MTCC 443 was 0.7%. This comparative study showed that lemon peel oil had better physicochemical and antioxidant property. Lemon peel oil can be used as a preservative in the food system as it exhibited antibacterial and antifungal activity

Crystal structure of isobutyl 4-(2-chloro-phenyl)-5-cyano-6-{(E)-[(dimethylamino)-methylidene]amino}-2-methyl-4H-pyran-3-carboxylate

The authors thank Dr Babu Varghese, Senior Scientific Officer SAIF, IIT Madras, India, for carrying out the data collection.Peer reviewedPublisher PD

Fiber-optic probe for noninvasive real-time determination of tissue optical properties at multiple wavelengths

We present a compact, fast, and versatile fiber-optic probe system for real-time determination of tissue optical properties from spatially resolved continuous-wave diffuse reflectance measurements. The system collects one set of reflectance data from six source-detector distances at four arbitrary wavelengths with a maximum overall sampling rate of 100 Hz. Multivariate calibration techniques based on two-dimensional polynomial fitting are employed to extract and display the absorption and reduced scattering coefficients in real-time mode. The four wavelengths of the current configuration are 660, 785, 805, and 974 nm, respectively. Cross-validation tests on a 6 x 7 calibration matrix of Intralipid-dye phantoms showed that the mean prediction error at, e.g., 785 nm was 2.8% for the absorption coefficient and 1.3% for the reduced scattering coefficient. The errors are relative to the range of the optical properties of the phantoms at 785 nm, which were 0-0.3/cm for the absorption coefficient and 6-16/cm for the reduced scattering coefficient. Finally, we also present and discuss results from preliminary skin tissue measurements. (C) 2001 Optical Society of Americ

Metal triflates catalyzed efficient synthesis of 3,4-dihydro-2H-1-benzopyrans

Ytterbium triflate efficiently catalyzes an unusual cyclization of o-hydroxybenzaldehydes with 2,3-dihydrofuran and 3,4-dihydro-2H-pyran in the presence of trimethyl orthoformate at ambient temperature to afford a new class of compounds, furo- and pyrano[2,3-b]benzopyrans in excellent yields with high diastereoselectivity. Also, o-hydroxybenzaldehydes reacted smoothly with acetophenones in the presence of a catalytic amount of scandium triflate under similar reaction conditions to give the corresponding 2,4-dialkoxy-2-aryl-3,4-dihydro-2H-1-benzopyrans in high yields

Phytophthora infestans induced defense response in calli of wild and cultivated potato genotypes: Pathogen induced cell death in cultures - a marker for resistance

Late Blight caused by Phytophthora infestans (Mont.) de Bary is the most destructive foliar disease causing 30% yield losses in the potato (Solanum tuberosum L.) crop globally. Wild potato genotypes AC1 and AC4, and potato cultivar Kufri Girdhari are highly resistant, whereas wild genotype AC6, and cultivars Kufri Chandramuki and Kufri Jyoti are susceptible to Late Blight. In the current study, the calli of these six potato genotypes were used to understand the mechanism of cellular resistance to Late Blight. Exposure to P. infestans or its elicitors significantly induced peroxidase (POX) and superoxide dismutase (SOD) activities, and induced accumulation of phenolics and flavonoids, indicating the capability of the calli cells to mount a defense response. The study is the first to report the extracellular secretion of defense enzymes, SOD and POX when cells encounter the pathogen, implicating a similar whole-plant phenomenon of enhanced defense in the apoplast. Interestingly, the calli of resistant genotypes showed poor survival upon exposure to pathogen or when grown on elicitor medium, while the susceptible genotypes showed better survival. The percentage of calli cells accumulating intracellular H2O2 was high in resistant genotypes, and directly correlated with the observed higher cell death. The study shows that H2O2 accumulation in the cells of resistant genotypes is indeed self-destructive, a whole plant phenomenon termed hypersensitive response - cell death at site of infection. The potato callus system thus can be used to gain new insights into the plant-defense response to P. infestans

Pre-Menopausal Women With Breast Cancers Having High AR/ER Ratios in the Context of Higher Circulating Testosterone Tend to Have Poorer Outcomes

PurposeWomen with breast tumors with higher expression of AR are in general known to have better survival outcomes while a high AR/ER ratio is associated with poor outcomes in hormone receptor positive breast cancers mostly in post menopausal women. We have evaluated the AR/ER ratio in the context of circulating androgens specifically in patients younger than 50 years most of whom are pre-menopausal and hence have a high estrogenic hormonal milieu.MethodsTumor samples from patients 50 years or younger at first diagnosis were chosen from a larger cohort of 270 patients with median follow-up of 72 months. Expression levels of ER and AR proteins were detected by immunohistochemistry (IHC) and the transcript levels by quantitative PCR. Ciculating levels of total testosterone were estimated from serum samples. A ratio of AR/ER was derived using the transcript levels, and tumors were dichotomized into high and low ratio groups based on the third quartile value. Survival and the prognostic significance of the ratio was compared between the low and high ratio groups in all tumors and also within ER positive tumors. Results were further validated in external datasets (TCGA and METABRIC).ResultsEighty-eight (32%) patients were ≤50 years, with 22 having high AR/ER ratio calculated using the transcript levels. Circulating levels of total testosterone were higher in women whose tumors had a high AR/ER ratio (p = 0.02). Tumors with high AR/ER ratio had significantly poorer disease-free survival than those with low AR/ER ratio [HR-2.6 (95% CI-1.02–6.59) p = 0.04]. Evaluation of tumors with high AR/ER ratio within ER positive tumors alone reconfirmed the prognostic relevance of the high AR/ER ratio with a significant hazard ratio of 4.6 (95% CI-1.35–15.37, p = 0.01). Similar trends were observed in the TCGA and METABRIC dataset.ConclusionOur data in pre-menopausal women with breast cancer suggest that it is not merely the presence or absence of AR expression but the relative activity of ER, as well as the hormonal milieu of the patient that determine clinical outcomes, indicating that both context and interactions ultimately influence tumor behavior

Field Driven Pairing State Phase Transition in d_x^2-y^2+id_xy-Wave Superconductors

Within the framework of the Ginzburg-Landau theory for $d_{x^2-y^2}+id_{xy}$-wave superconductors, we discuss the pairing state phase transition in the absence of the Zeeman coupling between the Cooper pair orbital angular momentum and the magnetic field. We find that above a temperature $T_{\ast}$, the pairing state in a magnetic field is pure $d_{x^{2}-y^{2}}$-wave. However, below $T_{\ast}$, the pairing state is $d_{x^{2}-y^{2}}+id_{xy}$-wave at low fields, and it becomes pure $d_{x^{2}-y^{2}}$-wave at higher fields. Between these pairing states there exists a field driven phase transition . The transition field increases with decreasing temperature. In the field-temperature phase diagram, the phase transition line is obtained theoretically by a combined use of a variational method and the Virial theorem. The analytical result is found to be in good agreement with numerical simulation results of the Gingzburg-Landau equations. The validity of the variational method is discussed. The difference to the case with the Zeeman coupling is discussed, which may be utilized to the detection of the Zeeman coupling.Comment: 5 pages, 2 figures, submitted to PRB Brief Repor