Naphtho[2,3-b][1,4]-thiazine-5,10-diones and 3-substituted-1,4-dioxo-1,4-dihydronaphthalen-2-yl-thioalkanoate derivatives: synthesis and biological evaluation as potential antibacterial and antifungal agents

A series of 3-substituted-1,4-dioxo-1,4-dihydronaphthalen-2-yl-thio-alkanoate derivatives 3-21 and naphtho[2,3-b][1,4]-thiazine-5,10-diones 24 were synthesized and evaluated for their antibacterial and antifungal activities. The structure-activity relationships of these compounds were studied and the results show that the compound 24a exhibited better antibacterial activity than Gentamycin in vitro against Staphylococcus aureus. In addition 24a also imparted marked antifungal activity in vitro against Cryptococcus neoformans, Sporothrix schenckii, and Trichophyton mentagraphytes when compared with Fluconazole. Compounds 15, 18, 19, and 21 also exhibited significant antibacterial activity in vitro against S. aureus.     

Osteogenic activity of constituents from Butea monosperma

Phytochemical investigation from the stem bark of Butea monosperma, led to the isolation and identification of three new compounds named buteaspermin A (1), buteaspermin B (2) and buteaspermanol (3), along with 19 known compounds. The structure of compounds 1–22 were established on the basis of their spectroscopic data. The isolated compounds 2–17 were evaluated using neonatal (1–3 day old) rat calvaria derived primary osteoblast cultures. Five of these compounds 7, 10–13 showed promising osteogenic activity, attributed to increased osteoblast proliferation, differentiation and mineralization as evidenced by marked increase in expression of alkaline phosphatase, an early phase differentiation marker, and alizarin Red S staining of osteoblasts cultured for 48 h and von Kossa silver staining of nodules formed 15 days after culture with these compounds. Quantification of mineralization by optical density measurement of Alizarin Red S extracted from stained osteoblasts cultured for 7 days in presence of these compounds showed significant (P < 0.05, vs corresponding vehicle control group) increase in mineralization. On the basis of biological results, structure–activity relationships are discussed.     

Methoxylated isoflavones,cajanin and isoformononetin,have non‐estrogenic bone forming effect via differential mitogen activated protein kinase (MAPK) signaling

Following a lead obtained from stem‐bark extract of Butea monosperma, two structurally related methoxyisoflavones; cajanin and isoformononetin were studied for their effects in osteoblasts. Cajanin had strong mitogenic as well as differentiation‐promoting effects on osteoblasts that involved subsequent activation of MEK‐Erk and Akt pathways. On the other hand, isoformononetin exhibited potent anti‐apoptotic effect in addition to promoting osteoblast differentiation that involved parallel activation of MEK‐Erk and Akt pathways. Unlike genistein or daidzein, none of these two compounds appear to act via estrogen receptors in osteoblast. Once daily oral (by gavage) treatment for 30 consecutive days was given to recently weaned female Sprague–Dawley rats with each of these compounds at 10.0 mg kg^?1 day^?1 dose. Cajanin increased bone mineral density (BMD) at all skeletal sites studied, bone biomechanical strength, mineral apposition rate (MAR) and bone formation rate (BFR), compared with control. BMD levels at various anatomic positions were also increased with isoformononetin compared with control however, its effect was less potent than cajanin. Isoformononetin had no effect on the parameters of bone biomechanical strength although it enhanced MAR and BFR compared with control. Isoformononetin had very mild uterotrophic effect, whereas cajanin was devoid of any such effect. Our data suggest that cajanin is more potent than isoformononetin in accelerating peak bone mass achievement. To the best of our knowledge, this work represents the first attempt to elucidate structure‐activity relationship between the two methoxylated isoflavones regarding their effects in osteoblasts and bone formation. J. Cell. Biochem. 108: 388–399, 2009. © 2009 Wiley‐Liss, Inc.     

Pyranocoumarins: A new class of anti-hyperglycemic and anti-dyslipidemic agents

A series of pyranocoumarin derivatives were synthesized and evaluated in vivo for their anti-hyperglycemic as well as anti-dyslipidemic activities. Compounds 7a, 7c, 8a, 8b, 8c, 8e and 8f have shown promising anti-hyperglycemic activities in sucrose loaded model (SLM) as well as sucrose challenged streptozotocin induced diabetic rat model (STZ). Compounds 8a and 8b were showing 38.0% and 42.0% blood glucose lowering activity in db/db mice model. In vitro anti-hyperglycemic activity evaluation exhibited that compounds 8a (IC₅₀ = 24.5 μM) and 8b (IC₅₀ = 36.2 μM) are potential PTP-1B inhibitors thereby revealing their possible mechanism of anti-diabetic action. Compounds 7a, 7b, 8a, 8b, 8d, 8e and 8f have shown significant anti-dyslipidemic activity in triton induced dyslipidemia in rats.     

Large-scale separation of clavine alkaloids from Ipomoea muricata by pH-zone-refining centrifugal partition chromatography

Centrifugal partition chromatography in the pH-zone-refining mode was successfully applied to the separation of alkaloids, directly from a crude extract of Ipomoea muricata. The experiment was performed with a two-phase solvent system composed of methyl tert-butyl ether (MtBE)–acetonitrile–water (4:1:5, v/v) where triethylamine (10 mM) was added to the upper organic stationary phase as a retainer and trifluoroacetic acid (10 mM) to the aqueous mobile phase as an eluter. From 4 g of crude extract, 210 mg lysergol and 182 mg chanoclavine were obtained in 97% and 79.6% purities. Total yield recovery was >95%. Isolated alkaloids were characterized on the basis of their ¹H, ¹³C NMR and ESI-MS data.     

Design, synthesis, and biological evaluation of 1,2,3-trisubstituted-1,4-dihydrobenzo[g]quinoxaline-5,10-diones and related compounds as antifungal and antibacterial agents

A series of (S)-N-(3-chloro-1,4-naphthoquinon-2-yl)-alpha-amino acid ethyl esters 3 and 1,2,3-trisubstituted-1,4-dihydrobenzo[g]quinoxaline-5,10-diones 6-23 were synthesized and evaluated for antifungal and antibacterial activities. The structure-activity relationship of these compounds was studied and the results show that the compounds 3a and 3b exhibited in vitro antifungal activity against Candida albicans, Cryptococcus neoformans, and Sporothrix schenckii whereas compounds 12 and 22 showed in vitro antibacterial activity against Klebsiella pneumoniae and Escherichia coli.     

Effect of cryoprotectants and their concentration on in vitro development of vitrified-warmed immature oocytes in buffalo (Bubalus bubalis)

Experiments were conducted to study the effect of cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), 1,2-propanediol (PROH), and glycerol at different concentrations (3.5, 4, 5, 6, and 7 M each with 0.5 M sucrose and 0.4% BSA in DPBS) on survival, in vitro maturation, in vitro fertilization, and post-fertilization development of vitrified-thawed immature buffalo oocytes. The COCs were harvested from the ovaries by aspirating the visible follicles. The recovery of post-thaw morphologically normal oocytes was lower in 3.5 and 4 M DMSO, EG, and PROH compared to 5, 6, and 7 M. In all the concentrations of glycerol, an overall lower numbers of oocytes recovered were normal compared to other cryoprotectants. Less number of oocytes reached metaphase-II (M-II) stage from the oocytes cryopreserved in any of the concentrations of DMSO, EG, PROH, and glycerol compared to fresh oocytes. Among the vitrified groups, highest maturation was obtained in 7 M solutions of all the cryoprotectants. The cleavage rates of oocytes vitrified in different concentrations of DMSO, EG, PROH, and glycerol were lower than that of the fresh oocytes. The cleavage rates were higher in oocytes cryopreserved in 6 and 7 M DMSO, EG, PROH, and glycerol compared with oocytes cryopreserved in other concentrations. However, the percentage of morula and blastocyst formation from the cleaved embryos did not vary in fresh oocytes and vitrified oocytes. In conclusion, this report describes the first successful production of buffalo blastocysts from immature oocytes cryopreserved by vitrification.     

Constituents of Pterocarpus marsupium: an ayurvedic crude drug

Five new flavonoid C-glucosides, 6-hydroxy-2-(4-hydroxybenzyl)-benzofuran-7-C-beta-d-glucopyranoside (1), 3-(alpha-methoxy-4-hydroxybenzylidene)-6-hydroxybenzo-2(3H)-furanone-7-C-beta-d-glucopyranoside (2), 2-hydroxy-2-p-hydroxybenzyl-3(2H)-6-hydroxybenzofuranone-7-C-beta-d-glucopyranoside (4), 8-(C-beta-d-glucopyranosyl)-7,3',4'-trihydroxyflavone (5) and 1,2-bis(2,4-dihydroxy,3-C-glucopyranosyl)-ethanedione (6) and two known compounds C-beta-d-glucopyranosyl-2,6-dihydroxyl benzene (7) and sesquiterpene (8), were isolated from an aqueous extract of the heartwood of Pterocarpus marsupium. The structure has been established using spectroscopic data.     

Graded Maximal Exercise Testing to Assess Mouse Cardio-Metabolic Phenotypes

Functional assessments of cardiovascular fitness (CVF) are needed to establish animal models of dysfunction, test the effects of novel therapeutics, and establish the cardio-metabolic phenotype of mice. In humans, the graded maximal exercise test (GXT) is a standardized diagnostic for assessing CVF and mortality risk. These tests, which consist of concurrent staged increases in running speed and inclination, provide diagnostic cardio-metabolic parameters, such as, VO_2max, anaerobic threshold, and metabolic crossover. Unlike the human-GXT, published mouse treadmill tests have set, not staged, increases in inclination as speed progress until exhaustion (PXT). Additionally, they often lack multiple cardio-metabolic parameters. Here, we developed a mouse-GXT with the intent of improving mouse-exercise testing sensitivity and developing translatable parameters to assess CVF in healthy and dysfunctional mice. The mouse-GXT, like the human-GXT, incorporated staged increases in inclination, speed, and intensity; and, was designed by considering imitations of the PXT and differences between human and mouse physiology. The mouse-GXT and PXTs were both tested in healthy mice (C57BL/6J, FVBN/J) to determine their ability to identify cardio-metabolic parameters (anaerobic threshold, VO_2max, metabolic crossover) observed in human-GXTs. Next, theses assays were tested on established diet-induced (obese-C57BL/6J) and genetic (cardiac isoform Casq2^-/-) models of cardiovascular dysfunction. Results showed that both tests reported VO_2max and provided reproducible data about performance. Only the mouse-GXT reproducibly identified anaerobic threshold, metabolic crossover, and detected impaired CVF in dysfunctional models. Our findings demonstrated that the mouse-GXT is a sensitive, non-invasive, and cost-effective method for assessing CVF in mice. This new test can be used as a functional assessment to determine the cardio-metabolic phenotype of various animal models or the effects of novel therapeutics.