Increases in cytokinin levels in Scots pine in relation to chilling and bud burst

Levels of isopentenyladenosine and zeatin riboside were monitored in buds and needles of Scots pine ( Pinus sylvestris L.) seedlings grown under controlled climatic conditions and in field-grown trees. Extracts were purified by immunoaffinity chromatography and high-performance liquid chromatography. Cytokinin levels were quantified with an enzyme-linked immunosorbent assay. The cytokinin content was low in buds and needles of dormant seedlings but increased during dormancy release, reaching peak values in buds just before resumption of shoot growth. Samples collected in the field also showed a marked increase in the levels of cytokinins just prior to bud burst. Further, the biological activity of applied cytokinins in activating the dormant buds of Scots pine is shown. The results indicate a probable role of cytokinins in seedlings during dormancy release.     

Structural characterization of a novel mono-sulfated gangliotriaosylceramide containing a 3-O-sulfatedN-acetylgalactosamine from rat kidney

A novel mono-sulfated glycosphingolipid based on the gangliotriaose core structure was isolated from rat kidney. The isolation procedure involved extraction of lipids with chloroform/methanol, mild alkaline methanolysis, column chromatographies with anion exchangers and silica beads. The structure was characterized by compositional analysis, FTIR spectroscopy, methylation analysis,¹H-NMR spectroscopy and negative-ion liquid secondary ion mass spectrometry (LSIMS) using the intact glycolipid and its desulfation product. The two dimensional chemical shift correlated spectroscopy provided information on the sugar sequence as well as anomeric configurations, and indicated the presence of a 3-O-sulfatedN-acetylgalactosamine within the molecule. Negative-ion LSIMS with high- and low-energy collision-induced dissociation defined the sugar sequence and ceramide composition, confirming the presence of a sulfatedN-acetylgalactosamine at the non-reducing terminus. From these results, the complete structure was proposed to be HSO₃-3GalNAc1-4Gal1-4Glc1-1Cer (Gg₃Cer III³-sulfate, SM2b). Abbreviations: Abbreviations for sulfated glycolipids [17] follow the modifications of the nomenclature system of Svennerholm for gangliosides [37], and the designation of the other glycosphingolipids follows the IUPAC-IUB recommendations [38]. Cer, ceramide; LacCer, lactosylceramide, Gal1-4Glc1-1Cer; Gg₃Cer, gangliotriaosylceramide, GalNAc1-4Gal1-4Glc1-1Cer; Gg₄Cer, gangliotetraosylceramide, Gal1-3GalNAc1-4Gal1-4Glc1-1Cer; iGb₄Cer, isoglobotetraosylceramide, GalNAc1-3Gal1-3Gal1-4Glc1-1Cer; Gb₄Cer, globotetraosylceramide, GalNAc1-3Gal1-4Gal1-4Glc1-1Cer; SM4s, galactosylceramide sulfate, GalCer I³-sulfate; SM3, lactosylceramide sulfate, LacCer II³-sulfate; SM2a, Gg₃Cer II³-sulfate; SM2b, Gg₃Cer III³-sulfate; SB2, Gg₃Cer II³,III³-bis-sulfate; SM1a, Gg₄Cer II³-sulfate; SM1b, Gg₄Cer IV³-sulfate; SB1a, Gg₄Cer II³,IV³-bissulfate; GLC, gas-liquid chromatography; GC-MS, gas chromatography-mass spectrometry; DQF, double quantum filtered; COSY, chemical-shift-correlated spectroscopy; LSIMS, liquid secondary ion mass spectrometry; CID, collision-induced dissociation; MS/MS, tandem mass spectrometry.     

Continuous,high capacity reconstitution of nutrient media from concentrated intermediates

We designed an Integrated Media Preparation System (IMPS) for continuous, on-line preparation of cell culture media and delivery to intermediate storage vessels or directly to a bioreactor. Key components of the IMPS include: a high precision, continuous fluid mixing device; formulation-specific liquid medium concentrates; validated process controls and membrane filtration; and automated dispensing into large volume flexible plastic containers. The IMPS system is designed to produce sterile, single-strength liquid medium from common raw materials at a delivery rate of 1000–3000 liters per hour and will manufacture homogenous batches from several thousand liters to over 60,000 liters. Fortified nutrient media prepared from multi-component 50X concentrates have been demonstrated to accelerate bioreactor seed chains, increase product yield, and reduce the overall manufacturing cost of nutrient medium. A productivity matrix will analyze the fully-loaded costs and contrast alternative methods for media preparation against projected biological yield.Abbreviations IMPS Integrated Media Preparation System - 50X Nutrient fluid components formulated at fifty-fold final use concentration - 1X Nutrient fluid formulated at final, single-strength use concentration - cGMP Current Good Manufacturing Practices - SCADA Supervisory Control and Data Acquisition - PLC Process Logic Controller - LTI Life Technologies, Inc. - WFI Water for Injection - CIP Clean in place - SIP Sterilize in place - HPLC High performance liquid chromatography - DMEM Dulbecco's Modified Eagle's Medium     

Facilitated transport of lactic acid in a stirred transfer cell

The application of liquid membrane extraction to the recovery of lactic acid from model systems and fermentation media was investigated. An experimental study of the facilitated transport of lactic acid using ALIQUAT 336 as a mobile carrier in a stirred transfer cell is reported. The effect of stirring speed, initial lactic acid concentration, carrier concentration, and NaCl as a reagent in the acceptor phase are considered. (c) 1994 John Wiley & Sons, Inc.     

两种钙藻热解产出的气态和液态烃类

在２００℃至４００℃高温和还原条件下分别对仙掌藻和乳节藻两种钙质藻类进行热模拟降解实验,分离获得气态和液态烃类化合物。随着热解温度升高,两种钙藻产烃气量明显上升,其中甲烷与乙烷气的增加最多,同时两种钙藻产出的乙烷与乙烯比值都有规律地增加,但仙掌藻产烃气量高于乳节藻。这表明钙质藻类可能是天然气的一种重要母质来源。虽然这两种钙藻随温度增加热解产出的可溶有机质及族组分的变化规律不明显,但它们的正烷烃分布特征具有相类似的变化。未经热解时它们都以Ｃ１７为主峰的低碳数正烷烃占优势;当热解温度从２００℃增加到４００℃时,它们都又表现出以Ｃ２５或Ｃ２３为主峰的较高碳数正烷烃占优势的分布特征。这与富含钙藻化石的沉积岩样品中正烷烃的分布特征相一致,说明Ｃ２５或Ｃ２３为主峰的较高碳数正烷烃占优势的分布特征可能是钙藻热解有机质的一种判识标志．     

Direct resolution of ergot alkaloid enantiomers on a novel chiral silica-based stationary phase

A new covalently-bonded, silica-based stationary phase, using as the chiral selector the 1-(3-aminopropyl) derivative of (+)-(5R,8S,10R)-terguride, has been developed to resolve optically active isomers by HPLC. Good resolution of structurally related racemic ergot alkaloids were obtained using water-methanol mixtures as the eluent. Analysis of the influence of the type and concentration of the organic modifier, and the pH of the buffer in the mobile phase allowed the enantioseparation of these compounds to be optimized. Determination of the optical purity of a lisuride-containig drug is reported. © 1994 Wiley-Liss, Inc.     

Myosin light chain kinase expression during smooth muscle development

The expression of smooth muscle myosin light chain kinase (MLCK) was investigated during chicken gizzard development. The molecular weight and the antigenic properties of MLCK did not change during development. The use of anion exchange high performance liquid chromatography (HPLC) enabled us to distinguish between MLCKs from post-hatched and adult chickens. A partial amino acid sequence determination of 4-day-old gizzard MLCK failed to disclose differences in the primary sequences of the two proteins. The results suggest that MLCK has the same primary sequence in all sequences of the two proteins. The results suggest that MLCK has the same primary sequence in all stages of gizzard development, although charge variants due to post-translational modifications may exist.     

Emulsion liquid membrane extraction of lactic acid from aqueous solutions and fermentation broth

Studies on the batch extraction of lactic acid using an emulsion liquid membrane system are reported. The membrane phase consists of the tertiary amine carrier Alamine 336 and the surfactant Span 80 dissolved in n-heptane/paraffin and aqueous solutions of sodium carbonate in the internal phase. The effects of internal phase reagent, extraction temperature, and initial external phase pH on the extraction efficiency and the emulsion swelling are examined. A statistical factorial experiment on extraction from clarified lactic acid fermentation broth was carried out to obtain knowledge of the performance of the extraction system from a broth. The extraction efficiency from the fermentation broth is found to be lower as compared to aqueous solutions of pure lactic acid. The effect of pH and the presence of other ionic species on selectivity are discussed. (c) 1993 John Wiley & Sons, Inc.     

Extractive separation of penicillin G by facilitated transport via carrier supported liquid membranes

The facilitated transport of penicillin G (Pen G), through a supported liquid membrane with Amberlite LA-2 dissolved in 1-decanol, supported on a microporous polypropylene membrane, were studied. The distribution coefficient was obtained from a batch extraction experiment. The effects of flow rate, carrier concentration, initial concentration of Pen G, and the pH of feed and stripping phases on the transport rate of Pen G through the supported liquid membrane were also investigated. The results are in agreement with theoretical predictions, and it is demonstrated that the transport of Pen G through the supported liquid membrane is controlled simultaneously by mass transfer across both aqueous and liquid membranes. (c) 1993 John Wiley & Sons, Inc.     

Cyclic dipeptide-based small molecules modulate zinc-mediated liquid–liquid phase separation of tau

Liquid–liquid phase separation (LLPS) is a complex physicochemical phenomenon mediated by multivalent transient weak interactions among macromolecules like polymers, proteins, and nucleic acids. It has implications in cellular physiology and disease conditions like cancer and neurodegenerative disorders. Many proteins associated with neurodegenerative disorders like RNA binding protein FUS (FUsed in Sarcoma), alpha-synuclein (α-Syn), TAR DNA binding protein 43 (TDP-43), and tau are shown to undergo LLPS. Recently, the tau protein responsible for Alzheimer's disease (AD) and other tauopathies is shown to phase separate into condensates in vitro and in vivo. The diverse noncovalent interactions among the biomolecules dictate the complex LLPS phenomenon. There are limited chemical tools to modulate protein LLPS which has therapeutic potential for neurodegenerative disorders. We have rationally designed cyclic dipeptide (CDP)-based small-molecule modulators (SMMs) by integrating multiple chemical groups that offer diverse chemical interactions to modulate tau LLPS. Among them, compound 1c effectively inhibits and dissolves Zn-mediated tau LLPS condensates. The SMM also inhibits tau condensate-to-fibril transition (tau aggregation through LLPS). This approach of designing SMMs of LLPS establishes a novel platform that has potential implication for the development of therapeutics for neurodegenerative disorders.