Furanoflavonoids from Pongamia pinnata fruits

Fruits of Pongamia pinnata afforded four new furanoflavonoids, pongapinnol A-D (1-4), and a new coumestan, pongacoumestan (5) along with thirteen known compounds 6-18. Compounds 16 and 17 are isolated for the first time from this plant. The structures of isolated compounds were elucidated on the basis of spectroscopic data interpretation.     

Evidence of programmed cell death in post-phloem transport cells of the maternal pedicel tissue in developing caryopsis of maize

We present cellular- and ultracellular-level studies here to show developmental programmed cell death (PCD) of placento-chalazal (P-C) cell layers in maternal pedicel tissue in developing caryopses of normal seed (Mn1) and in the invertase-deficient miniature (mn1) seed mutant in maize (Zea mays). PCD was evidenced by loss of nuclei and all subcellular membranous organizations in many P-C layers. The terminal deoxynucleotidyl transferase-mediated X-dUTP nick-end labeling (TUNEL) stain that is diagnostic of apoptotic-like PCD identified spatially and temporally two distinctive subdomains, which coincided with nucellar and integumental P-C layers based on their developmental origins. The early phase of PCD in the nucellar P-C was TUNEL negative and was specific to only the fertilized caryopses, indicating that the signaling for PCD in these maternal cells originated in the zygotic tissues. In fact, the initiation of PCD coincided with endosperm cellularization and was rapidly and coordinately completed prior to the beginning of the major storage phase in endosperm. Cell shape in these cell layers was also influenced by the genotype of filial endosperm. The later phase of PCD was restricted to the integumental P-C layers underneath the nucellar cells and was TUNEL positive in both genotypes. The two subdomains of the P-C layers were also distinguishable by unique cell wall-associated phenolic compounds. Based on collective evidence, we infer that the nucellar PCD may have osmolytic etiology and may lead to activation of the post-phloem transport function of the P-C layer, whereas the integumental PCD was senescent related, in particular, protecting the maturing seed against microbes that may be transported from the maternal tissue.     

Electron transfer in natural and unnatural flavoporphyrins

The development of chemical models for enzymes and their chemical and physical studies constitutes an important area of research from a scientific as well as an industrial point of view. Covalently linked flavin and porphyrin (flavoporphyrins) have attracted attention due to their applications as chemical models for flavoproteins and related enzymes. In this review, the literature has been surveyed to provide a comprehensive coverage of the synthetic methodology and characterization techniques of various types of synthetic flavoporphyrins.     

Sequence analysis of plasmid pTS1 isolated from oral spirochetes

The naturally occurring plasmid pTS1, identified previously in several species of oral spirochetes, has now been completely sequenced. Analysis of the four open reading frames identified on the plasmid suggests the presence of genes involved in replication and mobilization.     

Aminoethoxyvinylglycine Effects on Late-Season Apple Fruit Maturation

Aminoethoxyvinylglycine (AVG) inhibits 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, and thus blocks ethylene synthesis. Preharvest foliar application of AVG to apple (Malus domestica Borkh.) fruit retards several key events of maturation including climacteric ethylene production, starch conversion to sugars, fruit softening, and abscission zone development. Although the impact of AVG on apple fruit maturation is well known, the biochemical basis of these effects is not well understood. The effects of AVG application on Redchief Delicious apple fruit maturation were studied. AVG applied four weeks prior to harvest significantly reduced internal ethylene levels, amylose degradation, and accumulation of sucrose, glucose, and sorbitol. Because AVG application coincidentally inhibited starch degradation and the increase in internal ethylene, we investigated the enzymatic basis of starch mobilization in apple fruit. Amylase activity was somewhat reduced in AVG-treated fruit. Amylase activity was less in AVG-treated fruit during the early stages of starch mobilization. Starch phosphorylase activity increased dramatically during the later stages of starch mobilization, but was not affected by AVG treatment. Soluble starch synthase activity was also unaffected by AVG treatment and remained constant throughout the eight-week harvest period. Moreover, AVG did not affect the levels of amylopectin, fructose, malate, ascorbate, citrate, or anthocyanin. These results suggest that apple fruit ripening has both ethylene-dependent and -independent processes occurring simultaneously.     

Redescription of a rare deep-sea batfish, <Emphasis Type="Italic">Halieutopsis bathyoreos</Emphasis> (Lophiiformes: Ogcocephalidae)

Halieutopsis bathyoreos Bradbury, 1988 (Lophiiformes: Ogcocephalidae), previously described only on the basis of the holotype (62.6mm in standard length) from the central North Pacific, is redescribed on the basis of the holotype and six additional specimens (41.2–68.7mm in standard length) collected from the western South Pacific, off Papua New Guinea, and the western North Pacific, including the Japanese Archipelago. Halieutopsis bathyoreos is distinguished from its congeners by having a shelflike rostrum extending anteriorly well beyond the mouth, a dorsal escal lobe slightly bisected ventrally, an illicial cavity square in outline and completely visible in ventral view, and lacking tubercles on the ventral surface of the disk. The following characters are newly added to the diagnoses of this species: rostrum width 21–29% of head length, tubercles on the dorsal surface of the disk about half the diameter of those on the lateral margin, and 13–15 large lateral-line scales on the tail.     

Triamterene-β-cyclodextrin systems: Preparation,characterization and in vivo evaluation

The purpose of this research was to improve the solubility and therefore dissolution and bioavailability of triamterene, a poorly water soluble diuretic, by complexation with β-cyclodextrin. Triamterene has been reported to show low bioavailability after oral administration, with wide intersubject variation. This study presents the formulation of solid dispersions of triamterene with β-cyclodextrin—by cogrinding, kneading, and coevaporation, using low pH conditions—and their characterizations, evaluation of improvement in dissolution profiles, and in vivo advantage. Phase solubility studies indicated complex with possible stoichiometry of 1∶1 and a stability constant of 167.67M⁻¹. The solid dispersions were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, x-ray diffraction, and differential scanning calorimetry studies. The characterization studies confirmed inclusion of the phenyl ring of triamterene within the nonpolar cavity of β-cyclodextrin in the coevaporate. Remarkable improvement in in vitro drug release profiles in 0.1 N HCl and pH 6.8 phosphate buffer was observed with all dispersions, especially the coevaporate. The coevaporate, when administered orally in rats, also exhibited improved in vivo activity, as measured by net sodium ion excretion, as compared with triamterene powder. Thus, coevaporation of the drug and β-cyclodextrin from acidified alcohol provide the optimum condition for inclusion complexation to give a binary system with remarkable improvement in in vitro drug release profile and in vivo performance.     

The prevalence and correlates of consanguineous marriages in Yemen: similarities and contrasts with other Arab countries

Using data on 9762 women from the 1997 Yemen Demographic and Maternal and Child Health Survey, this paper examines the prevalence and socioeconomic correlates of consanguineous marriages in Yemen. The results indicate that 40% of marriages are consanguineous, over 85% of which are between first cousins. The prevalence of consanguineous marriages appears to have increased over time, particularly for the last marriage cohort. As for socioeconomic correlates, the study confirms the inverse association between consanguineous marriages and women's education and occupation, age at marriage and economic status. However, no statistically significant difference in the prevalence of consanguinity has been found by place of residence and geographical region. Somewhat unexpected results have been obtained by husband's background characteristics, with higher educated men and those working in the modern sector of the economy being more likely to be married to cousins.     

Hemozoin formation in malaria: a two-step process involving histidine-rich proteins and lipids

Major blood stage antimalarial drugs like chloroquine and artemisinin target the heme detoxification process of the malaria parasite. Hemozoin formation reactions in vitro using the Plasmodium falciparum histidine-rich protein-2 (Pfhrp-2), lipids, and auto-catalysis are slow and could not explain the speed of detoxification needed for parasite survival. Here, we show that malarial hemozoin formation is a coordinated two component process involving both lipids and histidine-rich proteins. Hemozoin formation efficiency in vitro is 1-2% with Pfhrp-2 and 0.25-0.5% with lipids. We added lipids after 9h in a 12h Pfhrp-2 mediated reaction that resulted in sixfold increase in hemozoin formation. However, a lipid mediated reaction in which Pfhrp-2 was added after 9h produced only twofold increase in hemozoin production compared to the reaction with Pfhrp-2 alone. Synthetic peptides corresponding to the Pfhrp-2 heme binding sequences, based on repeats of AHHAAD, neither alone nor in combination with lipids were able to generate hemozoin in vitro. These results indicate that hemozoin formation in malaria parasite involves both the lipids and the scaffolding proteins. Histidine-rich proteins might facilitate hemozoin formation by binding with a large number of heme molecules, and facilitating the dimer formation involving iron-carboxylate bond between two heme molecules, and lipids may then subsequently assist the mechanism of long chain formation, held together by hydrogen bonds or through extensive networking of hydrogen bonds.