Reactivity of phenyldi(2-thienyl)phosphine towards group 7 metal carbonyls: Carbon-phosphorus bond activation

Addition of phenyldi(2-thienyl)phosphine (PPhTh₂) to [Re₂(CO)_10−n(NCMe)_n] (n = 1, 2) affords the substitution products [Re₂(CO)_10−n(PhPTh₂)_n] (1, 2) together with small amounts of fac-[ClRe(CO)₃(PPhTh₂)₂] (3) (n = 2). Reaction of [Re₂(CO)₁₀] with PPhTh₂ in refluxing xylene affords a mixture which includes 2, [Re₂(CO)₇(PPhTh₂)(μ-PPhTh)(μ-H)] (4), [Re₂(CO)₇(PPhTh₂)(μ-PPhTh)(μ-η¹,κ¹(S)-C₄H₃S)] (5) and mer-[HRe(CO)₃(PPhTh₂)₂] (6). Phosphido-bridged 4 and 5 are formed by the carbon-phosphorus bond cleavage of the coordinated PPhTh₂ ligand, the cleaved thienyl group being retained in the latter. Reaction of [Mn₂(CO)₁₀] with PPhTh₂ in refluxing toluene affords [Mn₂(CO)₉(PPhTh₂)] (7) and the carbon-phosphorus bond cleavage products [Mn₂(CO)₆(μ-PPhTh)(μ-η¹,η⁵-C₄H₃S)] (8) and [Mn₂(CO)₅(PPhTh₂)(μ-PPhTh)(μ-η¹,η⁵-C₄H₃S)] (9). Both 8 and 9 contain a bridging thienyl ligand which is bonded to one manganese atom in a η⁵-fashion.     

Is slow follicular growth the cause of silent estrus in water buffaloes?

The present experiment was conducted to study the growth profile of the ovulatory follicle in relation to the expression of estrus following administration of PGF(2alpha) to subestrus buffaloes. After detection of a mature corpus luteum by examination per rectum, confirmed by ultrasound scanning, subestrus buffaloes (n=20) were treated (Day 0) with single dose of Dinoprost tromethamin (25 mg, i.m.). Blood samples were collected at 0, 24 and 48 h after treatment for estimation of plasma progesterone concentration. Growth profile of the ovulatory follicle was monitored daily through ultrasound scanning starting from Day 0 until ovulation and the regression profile of CL was monitored at 0, 24 and 48 h of treatment. Estrus was detected by exposure to a fertile buffalo bull three times a day until expression of overt estrus or ovulation. Behavioral estrus was recorded in 14 animals and 6 animals ovulated silently. Sixteen animals including six animals with silent estrus ovulated from the dominant follicle present at treatment (Group A) and remaining four animals ovulated from the dominant follicle of succeeding follicular wave (Group B). The intervals from treatment to estrus (6.5+/-0.25 versus 3.2+/-0.27 days, P<0.001) and treatment to ovulation (7.5+/-0.25 versus 5.4+/-0.46 days, P<0.005) were significantly longer in animals of Group B compared with animals of Group A. Significant differences were observed in growth profile of the ovulatory follicle between animals of Groups A and B with respect to size of the follicle on Day 0 (9.8+/-0.7 versus 5.3+/-0.45 mm, P<0.001), daily growth rate (0.97+/-0.07 versus 1.6+/-0.2 mm/day, P<0.01) and increase in diameter (4.1+/-0.6 versus 7.8+/-0.7 mm, P<0.01). The animals with silent estrus (subgroup A-2) had significantly smaller diameter of the ovulatory follicle on Day 0 (7.7+/-0.4 versus 11.0+/-0.7 mm, P<0.005), its daily growth rate was significantly slower (0.7+/-0.02 versus 1.1+/-0.1 mm/day, P<0.01) and they recorded significantly longer interval from treatment to ovulation (7.3+/-0.56 versus 4.2+/-0.27 days, P<0.001) compared with the animals that showed overt estrus (subgroup A-1). The corpus luteum area (CL area) and plasma progesterone (P(4)) concentration declined continuously from 0 to 48 h after PGF(2alpha) treatment in the animals of both the Groups A and B. Non-significant differences were observed in mean CL area and plasma P(4) concentration at 0, 24 and 48 h post-treatment between animals of Groups A and B and also between animals of subgroups A-1 and A-2. The small size and the slow growth rate of the ovulatory follicle were identified as the possible cause of silent estrus in subestrus buffaloes after PGF(2alpha) treatment.     

Impact of yellow mite (Polyphagotarsonemus latus [Banks]) density on host's (Corchorus capsularis L.) phenology and assessment of yield loss under field conditions

Yellow mite, Polyphagotarsonemus latus [Banks] (Acari: Tarsonemidae) is one of the major pests of jute crops (Corchorus capsularis L.) in Bangladesh. In this study, indigenous varieties of jute were used for treatments, namely, CVL‐1, CVE‐3, BJC‐7370 and BJC‐83. The paired plot treatments (treated and untreated controls) were laid out under field conditions. The effects of yellow mite were studied at three stages of the jute plants: 60 days after sowing (DAS), 90 DAS and 120 DAS. A higher number of mite stages was observed up to 90 DAS and then declined up to 120 DAS in var. BJC‐7370 among two other varieties, Deshi and Tossa. The percentage of infestation and damage indexes (scale 0–5) were measured to relate yellow mite injuries to the number of leaves, leaf area, fresh leaf weight, dry leaf weight, soluble solids, plant height, base diameter, fiber weight, stick weight, number of flowers per plant, number of pods, pod weight per plant, seeds per pod, seed weight and 1000 seeds' weight of plants infested at three different phenological stages. The highest fiber yield loss was found in the variety BJC‐7370 (59.75%), followed by BJC‐83 (55.56%), CVE‐3 (54.30%) and CVL‐1 (50.05). The highest stick yield losses were found in the following order: BJC‐7370 (54.54%) > BJC‐83 (51.17%) > CVL‐1 (43.68%) > CVE‐3 (37.80%) and BJC‐7370 (30.33%) > CVL‐1 (27.83%) > BJC‐83 (24.16%) > CVE‐3 (22.11%) for the highest seed yield under field conditions for Corchorus capsularis. High yellow mite population in untreated checks decreased plant growth and showed significant losses in yield production for the variety BJC‐7370.     

Identification patterns of Trichoderma strains using morphological characteristics,phylogenetic analyses and lignocellulolytic activities

Molecular Biology Reports - Trichoderma is a genus of soil-borne fungus with an abundance of reports of its economic importance in the agriculture industry. Thus, the correct identification of...     

Limonene-induced activation of A2A adenosine receptors reduces airway inflammation and reactivity in a mouse model of asthma

Animal models of asthma have shown that limonene, a naturally occurring terpene in citrus fruits, can reduce inflammation and airway reactivity. However, the mechanism of these effects is unknown. We first performed computational and molecular docking analyses that showed limonene could bind to both A_2A and A_2B receptors. The pharmacological studies were carried out with A_2A adenosine receptor knock-out (A_2AKO) and wild-type (WT) mice using ovalbumin (OVA) to generate the asthma phenotype. We investigated the effects of limonene on lung inflammation and airway responsiveness to methacholine (MCh) and NECA (nonselective adenosine analog) by administering limonene as an inhalation prior to OVA aerosol challenges in one group of allergic mice for both WT and KO. In whole-body plethysmography studies, we observed that airway responsiveness to MCh in WT SEN group was significantly lowered upon limonene treatment but no effect was observed in A_2AKO. Limonene also attenuated NECA-induced airway responsiveness in WT allergic mice with no effect being observed in A_2AKO groups. Differential BAL analysis showed that limonene reduced levels of eosinophils in allergic WT mice but not in A_2AKO. However, limonene reduced neutrophils in sensitized A_2AKO mice, suggesting that it may activate A_2B receptors as well. These data indicate that limonene-induced reduction in airway inflammation and airway reactivity occurs mainly via activation of A_2AAR but A_2B receptors may also play a supporting role.

     

Design and synthesis of 1,3-biarylsulfanyl derivatives as new anti-breast cancer agents

A new series of 1,3-biarylsulfanyl derivatives (homodibenzyl core motif) have been designed and synthesized as new estrogen receptor ligands by chopping benzothiophene core of raloxifene to engender seco-raloxifene scaffold. All the synthesized compounds were screened for anti-proliferative, anti-osteoporotic, and anti-implantation activity. Compounds (35, 36) having basic amino anti-estrogenic side chain were exhibiting potential anti-proliferative activity in MCF-7, MDA-MB-231 and ishikawa cell lines. Some of the synthesized compounds having homodibenzyl motif (5, 8, 10) have shown moderate anti-osteoporotic activity.