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Science-world news | Science Section | EDUKACJA BIOLOGICZNA I ŚRODOWISKOWA 1/2014

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Science-world news

Fairy chemistry of fungi

In January a group of 22 scientists from Japan published in Angewandte Chemie a paper dedica-ted to fairy chemicals isoladedica-ted from plant tissues [1]. Short after that a little rewiew: Fairy Chemicals has been published in Nature [2].

Both substances have already been known to scientist since 2010 as the factors causing formation of the fairy

rings by the fungi (fig. 1).

The first scientific communication about fairy rings phenomenon by fungi was published in 1675 [5]. Sin-ce then people believed rings were an effect of fairies or other supernatural forces action. In 2010 scientists

from the Japanese Shizuoka University claimed that one of these fairies is in fact 2-azahypoxanthine (AHX) [6]. Figure 2 shows chemical formula as well as model of the substance mentioned above. 2-azahypoxanthine was isolated from Lepista sordida fungus which is wi-despread in northern temperate zones throughout the world. What is interesting scientists revealed that this substance isolated from fungus influenced the growth of germinating seeds, for instance rice, wheat and other plants (fig. 3).

What is more the group of scientists isolated AHX and its metabolite from tissues of different plants: rice,

Arabidopsis, potato, tomato, eucalyptus and Chlorella

Fig. 1. Exemplary photographs of the fairy rings [3], [4]

Fig. 2. Model (left) and stucture of 2-azahypoxanthine (AHX). Click in the link [7] to see 3D structure of AHX

Fig. 3. Rice grown in soil non supplemented (left) and

suplemented with AHX – 5μmol/dm3 (right) [1]

The news are prepared b_{y the specialists} from the Science Section of the Educational Resea_{rch Institute}

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EDUKACJA BIOLOGICZNA I ŚRODOWISKOWA | ebis.ibe.edu.pl | ebis@ibe.edu.pl | © for the article by the Authors 2014 © for the edition by Instytut Badań Edukacyjnych 2014 although plants and algae don’t form fairy rings.

De-tected concentrations of ASX were similar to concen-tartions of known plant hormones, for example strigo-lactones responsible for plant growth or plant steroids -brassinosteroids. In the next stages of research resear-chers had set up a hypothesis that plants themselves

pro-duce 2-azahypoxanthine through a biochemical pathway similar to the laboratory chemical synthesis. Detailed

laboratory analysis led them to the confirmation of the settled hypothesis.

As authors of the paper [1] stated, the increase of the seed yields of rice and wheat in pot experiments after treating them with AHX suggest the possibility of its practical use in agriculture.

Marcin Chrzanowski, Science Section

References:

[1] Choi JH, Ohnishi T, Yamakawa Y, Takeda S, Sekiguchi S, Ma-ruyama W, Yamashita K, Suzuki T, Morita A, Ikka T, Motohashi R, Kiriiwa Y, Tobina H, Asai T, Tokuyama S, Hirai H, Yasuda N, Noguchi K, Asakawa T, Sugiyama S, Kan T, Kawagishi H (2014). The Source of “Fairy Rings”: 2-Azahypoxanthine and its Metabo-lite Found in a Novel Purine Metabolic Pathway in Plants, Angew.

Chem. Int. Ed., 53:1-5.

[2] Mitchinson A (2014), Fairy chemicals, Nature (research and

views), 98:505.

[3] http://upload.wikimedia.org/wikipedia/commons/d/d7/Fairy_ ring%5E_-_geograph.org.uk_-_573051.jpg

[4] http://upload.wikimedia.org/wikipedia/commons/9/96/Fairy_ ring_on_a_suburban_lawn_100_1851.jpg

[5] Hutton Ch, Shaw G, Pearson R (1975), The Philosophical

Tran-sactions Of The Royal Society Of London, From Their Commen-cement, In 1665, To The Year 1800; With Notes And Biographic Illustrations, from 1672 to 1683, Vol. II., 225.

[6] Choi JH, Fushimi K, Abe N, Tanaka H, Maeda S, Morita A, Hara M, Motohashi R, Matsunaga J, Eguchi Y, Ishigaki N, Hashizume D, Koshino H, Kawagishi H (2010). Disclosure of the “Fairy” of Fairy-Ring-Forming Fungus Lepista sordida, ChemBioChem A

European Journal of Chemical Biology, 11:1373-1377.

[7] http://www.chemspider.com/ImageView.aspx?mode=3d &id=70758

A new cure for defects in the heart

A new superglue, officially known as hydrophobic light-activated adhesive (HLAA), was developed in a collaboration between researchers at Boston Children’s Hospital, Massachusetts Institute of Technology (MIT), and Harvard-affiliated Brigham and Women’s Hospital. This novel surgical adhe-sive is strong enough, and elastic enough, to seal a beating heart (Lang et al., 2014).

Many infants born with heart defects such as atrial

septal defect (ASD, commonly known as a hole in the heart), which must be treated surgically. Unfortunately,

this kind of medical interventions is difficult to perform

since both sutures and staples can damage the delicate heart tissue, and applying sutures is time consuming. Replacing the surgical sutures with fast-acting, biode-gradable glues could make these cardiac procedures fa-ster, safer, less invasive and help reduce postoperative complications, as well as recovery times. However, exis-ting, clinically approved surgical adhesives have several drawbacks i.a. they do not bind strongly enough to tis-sues in wet and highly dynamic environments within the body, and some of them can be toxic, thus they are applied mainly to the skin. Furthermore, infants often need subsequent operations to “replug” heart defect aga-in. This is going to change soon since scientists at

Bo-Fig. 1. Application of HLAA-coated patch to a heart defect

Source: http://www.gizmag.com/heart-hole-glue-hlaa/30414/ pictures#2

Fig. 2. HLAA sets in just five seconds, once it’s exposed to an ultraviolet light source

Source: http://www.gizmag.com/heart-hole-glue-hlaa/30414/ pictures#2

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EDUKACJA BIOLOGICZNA I ŚRODOWISKOWA | ebis.ibe.edu.pl | ebis@ibe.edu.pl | © for the article by the Authors 2014 © for the edition by Instytut Badań Edukacyjnych 2014 ston Children’s Hospital, MIT, and Harvard-affiliated

Brigham and Women’s Hospital have developed a sort of superglue, that quickly and securely bonds patches to the holes in the heart tissues. A biomaterials researcher Jeffrey Karp and his co-workers have described in the January issue of the journal Science Translational

Me-dicine the engineering of elastic and biocompatible hy-drophobic light-activated adhesive (HLAA) that

achie-ves a strong level of adhesion to wet tissue and is not compromised by pre-exposure to blood. The study reve-aled that HLAA can provide an on-demand hemostatic seal, within seconds of light application, when applied to high-pressure large blood vessels and cardiac wall

Fig. 3. A closer look at how the collagen in the tissue bonds with HLAA patch

Image: Pedro del Nido, Boston Children’s Hospital, source: http://www.gizmag.com/ heart-hole-glue-hlaa/30414/pictures#3 defects in pigs. HLAA-coated patches were attached to

the interventricular septum in a beating porcine heart and despite high pressure they remained attach for 24 hours, which is relevant to intracardiac interventions in humans. Due to HLAA’s unique properties patches will remain adhered to the heart tissue even in liquid blood, it won’t be rejected, loosen up or torn by the contra-ctions of the heart muscle, and it will biodegrade, when the hole has healed over.

Unlike adhesives that work through a chemical rea-ction, HLAA works by a physical mechanism. HLAA remains liquid in normal conditions but sets in just five seconds when it’s exposed to an ultraviolet light source

(fig. 2). Microscopy studies indicate that the glue beco-mes physically entangled with collagen and other prote-ins on the heart tissue surface (fig. 3).

According to the researchers, the HLAA glue can be used in cardiac surgery, and other kinds of surgical in-terventions requiring immediate repair of defects and surgical hemostasis. Until now the surgical adhesive has been tested on pigs and mice and is being developed by French company Gecko Biomedical, which plans to re-lease HLAA as a commercial product to the European market in one to two years.