scholarly journals Evaluation of Soda Lignin from Wheat Straw/Sarkanda Grass as a Potential Future Consolidant for Archaeological Wood

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 911
Author(s):  
Jeannette J. Łucejko ◽  
Anne de Lamotte ◽  
Fabrizio Andriulo ◽  
Hartmut Kutzke ◽  
Stephen Harding ◽  
...  

This work is part of a larger study, which aims to use soda lignin from straw as the starting point for a non-aqueous consolidant for highly degraded archaeological wood from the Oseberg collection. This wood was treated with alum salts in the early 1900s, is actively degrading and exists in varying states of preservation. Non-aqueous consolidants are an option to stabilize this wood mechanically in cases where it is too deteriorated to undergo aqueous-based retreatments, for example using polyethylene glycol. The aim of this study was to compare the extent of penetration of two soda lignin preparations in low- to medium-degraded archaeological pine. The soda lignins were dissolved in ethyl acetate and had two molecular weight groups: P1000 (molecular weight Mw of~3 kDa) and the ethyl acetate fraction FB01 (Mw of ~1 kDa). Penetration after immersion was evaluated by infrared spectroscopy and analytical pyrolysis. Treated specimens were also evaluated using weight and dimensional change and scanning electron microscopy. Both lignins penetrated into sample cores, but P1000 did not penetrate as well as FB01. This may be due to differences in their molecular weights, but also differences in polarity due to the presence of different functional groups.

1974 ◽  
Vol 52 (24) ◽  
pp. 4123-4132 ◽  
Author(s):  
Jean A. Neyroud ◽  
Morris Schnitzer

Fulvic acid (FA) was methylated, dissolved in benzene, and fractionated over Al2O3 with the aid of organic solvents of increasing polarities. This paper is concerned with fractions eluted with ethyl acetate (III), ethyl acetate — methanol (1:1) (IV), and methanol (V), which were quantitatively the most abundant ones and which we consider as being most representative of the original FA. Each fraction was characterized by chemical and spectroscopic methods and by degradation with alkaline permanganate. Fractions IV and V were also degraded by NaOH hydrolysis and by alkaline CuO-oxidation. The degradation products were identified with the aid of a gas chromatograph — mass spectrometer — computer system.The number-average molecular weights of the three fractions were: III, 821; IV, 945; and V, 1,397. Infrared, proton n.m.r., and carbon-13 n.m.r. spectra provided, except for functional groups, little detailed information on the chemical structures of the fractions. The major degradation products were benzenecarboxylic and phenolic acids in addition to smaller amounts of aliphatic (mainly n-fatty) acids. Evidence is presented that may be interpreted to indicate: (a) esterification of some of the fatty acids to OH groups of phenolic acids; (b) the existence in the fractions of ether (C—O) linkages; and (c) rupture of C—C bonds during degradation. While in both the lower and the higher molecular weight FA fractions benzenecarboxylic and phenolic acids were the basic "building blocks", the latter appeared to be more complex and more stable in the higher-molecular weight fractions, possibly because chemical bonding as well as hydrogen bonding, van der Waal's forces, and π-bonding were involved simultaneously.


ALCHEMY ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 38
Author(s):  
Elly Rustanti ◽  
Qurrotu A'yunin Lathifah

<p class="BodyAbstract">Avocado leaves (Persea americana Mill.) have many benefits in our health because the leaves contain many secondary metabolites. One of the secondary metabolites in avocado leaves is quercetin. Quercetin is the largest compound of the flavonols group in which percentage of quercetin and its glycosides is 60-75% of total flavonoids. The purpose of this study was to isolate quercetin compounds from ethyl acetate fraction of ethanol extract of avocado leaves and to determine the presence of quercetin compounds in the avocado leaves. The leaves were extracted by maceration using 95% ethanol and fractionated with ethyl acetate. Identification of quercetin compounds using liquid chromatography-mass spectrometry (LC-MS). The results of this study indicated that avocado leaf extract contained quercetin compounds with a retention time of 5.83 minutes with molecular weight m/z = 300.50-301.50 [M-H]<sup>+</sup>.</p><p class="BodyAbstract"> </p><p class="BodyAbstract">Keywords: Avocado leaves, quercetin, LC-MS <strong></strong></p><p class="BodyAbstract"><strong> </strong></p><p class="BodyAbstract">Daun alpukat (Persea americana Mill.) banyak memiliki kegunaan dalam kesehatan karena mengandung banyak metabolit sekunder. Salah satu metabolit sekunder yang terkandung dalam daun alpukat adalah kuersetin. Kuersetin adalah senyawa kelompok flavonol terbesar yang mana kuersetin dan glikosidanya berada dalam jumlah sekitar 60-75% dari flavonoid. Tujuan dari penelitian ini adalah untuk mengisolasi senyawa kuersetin dari fraksi etil asetat dari ekstrak etanol daun alpukat dan untuk mengetahui adanya senyawa kuersetin dalam daun alpukat. Daun alpukat diekstraksi dengan metode maserasi menggunakan pelarut etanol 95% dan difraksinasi dengan etil asetat. Identifikasi senyawa kuersetin dengan menggunakan kromatografi cair-spektrometri massa (KC-SM). Hasil dari penelitian ini menunjukkan bahwa dalam ekstrak daun alpukat mengandung senyawa kuersetin dengan waktu retensi 5,83 menit dengan berat molekul m/z= 300,50-301,50 [M-H]<sup>+</sup>.</p><p> </p><p>Kata kunci<strong>: </strong>Daun alpukat, kuersetin, KC-SM</p>


2013 ◽  
Vol 13 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Agnes Nora Iska Harnita ◽  
Ign. Edi Santosa ◽  
Sudibyo Martono ◽  
Sudarsono Sudarsono ◽  
Sitarina Widyarini ◽  
...  

This study examines the antioxidant activity of crude phlorotannins from the brown algae Sargassum hystrix v. buxifolium (Chauvin) J. Agardh, through the inhibition of a lipid peroxidation reaction that is induced by the UV radiation. The antioxidant activity during the UV exposure was investigated using the laser-based photoacoustic method for the detection of the ethylene as indicator for lipid peroxidation. This involves an experiment that isolated crude phlorotannins from the ethyl acetate fraction of the Sargassum hystrix methanol extract, hereafter referred to as PFSH. It results in the antioxidant activity as a potent lipid peroxidation inhibitor. Statistically, such antioxidant activity is not significantly different than the commercial antioxidant, which is vitamin C (p > 0.05). The amount of the total phlorotannins, using the Folin-Ciocalteu method, was measured to be approximately 0.13% w/w. In addition, it is found that PFSH contains phlorotannins with low molecular weight (MW) (


2010 ◽  
Vol 38 (02) ◽  
pp. 415-429 ◽  
Author(s):  
Hyun Ah Jung ◽  
Takako Yokozawa ◽  
Byung-Woo Kim ◽  
Jee H. Jung ◽  
Jae Sue Choi

It was previously reported that certain lavandulylated flavanones from Sophora flavescens are β-site APP cleaving enzyme 1 (BACE1) inhibitors; however, based upon their levels within the extract, their inhibitory effects should be higher than expected. Moreover, chalcones and flavonols were reported to exert higher bioactivities than flavanones. These findings have led to a further search for other possible constituents potentially contributing to the strong inhibitory activity of the S. flavescens extract. In this study, BACE1 activities were significantly inhibited by 8-lavandulylkaempferol (IC50 7.29 μM), kuraridinol (IC50 7.10 μM), kuraridin (IC50 6.03 μM), and kushenol C (IC50 5.45 μM) from the ethyl acetate fraction, along with desmethylanhydroicaritin (IC50 1.86 μM), xanthohumol (IC50 7.19 μM), and leachianone G (IC50 8.56 μM) from the dichloromethane fraction of the extract. The results indicate that the prenyl group, rather than the lavandulyl group, and the flavonols and chalcones, rather than flavanones, might make predominant contributions to BACE1 inhibition. In particular, 8-lavandulylkaempferol exhibited significant inhibitory effects with IC50 values of 7.10 and 8.11 μM for butyrylcholinesterase and acetylcholinesterase, respectively, when compared to its counterpart, desmethylanhydroicaritin. This indicates that the lavandulyl group might play a predominant role in both cholinesterase inhibitions. This is the first study indicating that prenylated flavonoids exert varying degrees of inhibition primarily through their skeleton (flavonols, chalcones, flavanones), as well as their lipophilic chain length (prenyl and lavandulyl groups). Therefore, S. flavescens and its prenylated flavonoids, possessing low molecular weights and lipophilic moieties may be potent preventive and therapeutic candidates for Alzheimer's disease.


1988 ◽  
Vol 60 (01) ◽  
pp. 107-112 ◽  
Author(s):  
Roy Harris ◽  
Louis Garcia Frade ◽  
Lesley J Creighton ◽  
Paul S Gascoine ◽  
Maher M Alexandroni ◽  
...  

SummaryThe catabolism of recombinant tissue plasminogen activator (rt-PA) was investigated after injection of radiolabelled material into rats. Both Iodogen and Chloramine T iodination procedures yielded similar biological activity loss in the resultant labelled rt-PA and had half lives in the rat circulation of 1 and 3 min respectively. Complex formation of rt-PA was investigated by HPLC gel exclusion (TSK G3000 SW) fractionation of rat plasma samples taken 1-2 min after 125I-rt-PA injection. A series of radiolabelled complexes of varying molecular weights were found. However, 60% of the counts were associated with a single large molecular weight complex (350–500 kDa) which was undetectable by immunologically based assays (ELISA and BIA) and showed only low activity with a functional promoter-type t-PA assay. Two major activity peaks in the HPLC fractions were associated with Tree t-PA and a complex having a molecular weight of ̴ 180 kDa. HPLC fractionation to produce these three peaks at various timed intervals after injection of 125I-rt-PA showed each to have a similar initial rate half life in the rat circulation of 4-5 min. The function of these complexes as yet is unclear but since a high proportion of rt-PA is associated with a high molecular weight complex with a short half life in the rat, we suggest that the formation of this complex may be a mechanism by which t-PA activity is initially regulated and finally cleared from the rat circulation.


1981 ◽  
Vol 45 (01) ◽  
pp. 090-094 ◽  
Author(s):  
Katsuo Sueishi ◽  
Shigeru Nanno ◽  
Kenzo Tanaka

SummaryFibrinogen degradation products were investigated for leukocyte chemotactic activity and for enhancement of vascular permeability. Both activities increased progressively with plasmin digestion of fibrinogen. Active fragments were partially purified from 24 hr-plasmin digests. Molecular weights of the permeability increasing and chemotactic activity fractions were 25,000-15,000 and 25,000 respectively. Both fractions had much higher activities than the fragment X, Y, D or E. Electron microscopic observation of the small blood vessels in rabbit skin correlated increased permeability with the formation of characteristic gaps between adjoining endothelial cells and their contraction.These findings suggest that lower molecular weight degradation products of fibrinogen may be influential in contributing to granulocytic infiltration and enhanced permeability in lesions characterized by deposits of fibrin and/or fibrinogen.


1964 ◽  
Vol 12 (01) ◽  
pp. 232-261 ◽  
Author(s):  
S Sasaki ◽  
T Takemoto ◽  
S Oka

SummaryTo demonstrate whether the intravascular precipitation of fibrinogen is responsible for the toxicity of heparinoid, the relation between the toxicity of heparinoid in vivo and the precipitation of fibrinogen in vitro was investigated, using dextran sulfate of various molecular weights and various heparinoids.1. There are close relationships between the molecular weight of dextran sulfate, its toxicity, and the quantity of fibrinogen precipitated.2. The close relationship between the toxicity and the precipitation of fibrinogen found for dextran sulfate holds good for other heparinoids regardless of their molecular structures.3. Histological findings suggest strongly that the pathological changes produced with dextran sulfate are caused primarily by the intravascular precipitates with occlusion of the capillaries.From these facts, it is concluded that the precipitates of fibrinogen with heparinoid may be the cause or at least the major cause of the toxicity of heparinoid.4. The most suitable molecular weight of dextran sulfate for clinical use was found to be 5,300 ~ 6,700, from the maximum value of the product (LD50 · Anticoagulant activity). This product (LD50 · Anticoagulant activity) can be employed generally to assess the comparative merits of various heparinoids.5. Clinical use of the dextran sulfate prepared on this basis gave satisfactory results. No severe reaction was observed. However, two delayed reactions, alopecia and thrombocytopenia, were observed. These two reactions seem to come from the cause other than intravascular precipitation.


1962 ◽  
Vol 08 (02) ◽  
pp. 270-275 ◽  
Author(s):  
David L Aronson ◽  
John W Preiss ◽  
Michael W Mosesson

SummaryThe molecular weights of AHF (factor VIII) and of PTC (factor IX) have been estimated by their sensitivity to inactivation by 7 kilovolt electrons. The molecular weight of AHF was found to be 180 000 by this method and that of PTC was found to be 110 000.


1963 ◽  
Vol 43 (3) ◽  
pp. 345-360 ◽  
Author(s):  
Stanley Kushinsky ◽  
Jane (Wu) Tang

ABSTRACT A convenient and mild procedure is described in this paper whereby free and conjugated oestrogens may be extracted from urine. The extracts containing approximately 90 per cent of the oestrogens are devoid of most of the extraneous material and may be reduced in volume to less than 1/15 of that of the urine. The procedure consists of the following steps: (1) a 10 per cent (v/v) solution of a high molecular weight secondary amine (Amberlite LA-2, Rohm and Haas) in ethyl acetate is washed with formic acid and water, (2) the oestrogens in urine (acidified to pH 2 or 3 with H2SO4) are extracted with the LA-2 solution, (3) the oestrogen fraction is back-extracted from the organic solution with dilute aqueous ammonia.


2019 ◽  
Vol 10 (04) ◽  
pp. 646-650
Author(s):  
Hyeusoo Kim ◽  
Kyeong Won Yun

The fruit of Rosa multiflora has been used as traditional herbal medicine in Asian countries. The present investigation was undertaken to study the antimicrobial activity and total polyphenol content of hexane, ether, ethyl acetate, water fraction of methanol extract of fruit and flower from Rosa multiflora and Rosa wichuraiana. Antimicrobial activity of the mentioned fractions against 3 gram-positive and 4 gram-negative bacteria using disk diffussion method. The measurement of minimal inhibition concentration (MIC) showed that the ethyl acetate fraction of the two Rosa species is the most effective against the tested bacteria. The total polyphenol content of ethyl acetate fraction of the two Rosa species is higher than the other fractions. The results indicate the antimicrobial activity was related with the total polyphenol content and the fruit and flower of the two Rosa species can be considered as a natural source of antimicrobial agents.


Sign in / Sign up

Export Citation Format

Share Document