Sulfonated magnetic carbon nanoparticles from eucalyptus oil as a green and sustainable catalyst for converting fructose to 5-HMF

Article abstract of DOI:10.1016/j.catcom.2020.106229

Sulfonated magnetic carbon nanoparticles (SMCNs) were synthesized from eucalyptus oil via co-pyrolysis with ferrocene and sulfonation by H₂SO₄. Catalytic performance of SMCNs for conversion of fructose to 5-hydroxymethylfurfural was examined within a designated range of reaction temperature (120–180 °C) and time (30–240 min). 84% conversion of fructose and 51.6% yield of 5-hydroxymethylfurfural could be achieved with catalyst-to-fructose mass ratio of 0.167 at 180 °C and the reaction time of 30 min. The magnetic property of SMCNs also facilitated recovery and recycling of the spent catalyst. Additionally, more than 50% yield of 5-hydroxymethylfurfural could be achieved after three cycles.

Full text of DOI:10.1016/j.catcom.2020.106229

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disproportionating the S0 into sulphide
and sulphate, where the latter can
be recycled by the archaea. While
these two parts of the process can be
knowledge on dry land, but is still a
frontier on the sea floor.
Frank Scheckenbach and colleagues
at the University of Cologne, Germany,
Q & A
Eleanor A. Maguire
teased apart in the lab, the coordinated have described the diversity of single-
growth rates of bacteria and archaea
in natural settings suggests that they
work closely together, with S0 being
the chemical species linking the
reactions. Luzan likens the bacteria
to scavengers in the animal kingdom:
“According to this new paper, the
relationship between the sulphate-
reducing bacterium and archaeon
is more like that between lion and
hyena — like the hyena, the bacterium
takes the leftovers.”
cell eukaryotes on the deep sea floor
at 5,000 metres depth for three abyssal
plains in the southeastern Atlantic (Proc. Cognitive Neuroscience and a
Natl. Acad. Sci. USA (2010), 107, 115–
120). They found great phylogenetic
diversity, providing just a glimpse of the
wealth of biology we’re still missing out
on in these depths.
Eleanor Maguire is Professor of
Wellcome Trust Senior Research
Fellow at the Wellcome Trust Centre
for Neuroimaging, University College
London, where she is also Deputy
Director. Her undergraduate degree
in psychology at University College
Dublin was followed by an MSc
In an attempt to map diversity
vertically rather than horizontally, the
groups of Steffen Leth Jørgensen
from the Centre for Geobiology at the
University of Bergen, Norway, and
Christa Schleper from the University of
Vienna, Austria, have profiled microbial
communities in correlation to their
geological context (Proc. Natl. Acad.
Sci. USA (2012) 109, E2846–E2855).
The authors analysed two drill cores,
each three metres long, from the Arctic
in neuropsychology at Swansea
University, UK, and then a PhD back
in Dublin which was completed while
working as a neuropsychologist in
Ireland’s then largest neurological and
neurosurgical hospital. In 1995 she
joined University College London, UK,
as a postdoc at the new Functional
Imaging Laboratory (FIL) where, after
a number of years, she set up her own
lab combining neuropsychology and
neuroimaging to study how spatial
and episodic memories are formed,
represented and recollected by the
human brain. Eleanor is a Fellow of the
Academy of Medical Sciences and has
won numerous prizes for outstanding
contributions to science including
the Royal Society Rosalind Franklin
Award, and also the Ig Nobel Prize for
Medicine which celebrated her work
on plasticity in the brains of London
taxi drivers.
While Milucka and colleagues
base their current analysis on just
one location, they believe that the
mechanisms may be widespread,
as similar sediments occur in many
parts of the sea floor. “Our cultures
originate from sediments of a marine
mud volcano, which represents a
typical habitat in which AOM is regularly mid-ocean ridge system that runs
found,” says Milucka. “Interestingly,
our observations, such as production
and accumulation of elemental sulphur,
have also been reported from so-called
sulphate–methane transition zones,
which represent another common
habitat of AOM.”
Globally, this biological degradation
of methane is an extremely important
factor for climate stability. “Under the
environmental conditions prevalent in
anoxic marine sediments methane is
very stable and unreactive,” Milucka
explains. “Therefore, microbial activity
is necessary for its breakdown.
parallel to the east coast of Greenland.
They obtained both cores at a distance
of 15 km from an active hydrothermal
vent field. In these locations, the
alternating depositions of sediments
carried by a river on Bear Island and
hydrothermal vent output leads to
strongly pronounced geological layer
structures within a modest depth range.
Studying 15 separate sediment
horizons and analysing the sequences
of around 60,000 microbial 16S rRNA
genes, Jørgensen and colleagues could
associate microbial communities with
specific types of sediments. They come
to the conclusion “that organic carbon
and mineral (iron and manganese)
content are key determinants of
What turned you on to biology, and
neuroscience in particular? From an
early age I had an insatiable thirst for
facts which was most acute in three
domains — archaeology, astronomy
and biology. When it came to making
choices for university, my parents
ruled out archaeology as they felt I
couldn’t make a decent living from it!
In Dublin in the late 1980s, studying
astronomy seemed like pie in the sky.
So I quite happily plumped for a career
in biology. Visits to the local university
arranged by my biology teacher
quickly confirmed that a wet lab was
not for me, and consequently I fell
into psychology. To be honest, I didn’t
really enjoy it at first, but then the
neuropsychology module started, and
I was hooked; the brain — here was
something tractable that challenged
and completely absorbed.
Microbially-mediated anaerobic
methane oxidation is a key process
regulating the flux of methane into the
water column. It is estimated that AOM
consumes up to 90% of the methane
diffusing from marine sediments, which
equals ca. 300 Tg per year. However,
it is the interplay between both the
aerobic and anaerobic oxidation of
methane in the water column and the
sediment, respectively, that protects
our atmosphere from the effects of this
greenhouse gas.”
microbial community structure.
Conversely, the community structure
is a likely determinant of the sulphate
concentration.”
Linking geology to ecology in this
way can help to form hypotheses about
less accessible habitats, the authors
say. Thus it may help to push back the
boundaries of those vast uncharted
territories remaining on our own
planet. As humanity is confronted with
planetary problems like climate change
and ocean acidification, our lack of
knowledge regarding the 72% of our
planet covered by oceans is becoming
downright dangerous.
Three dimensions of diversity
Apart from these surprising new
reactions and processes that need
to be explored in more depth, a
lot of the more mundane work of
mapping habitats and linking species
to geological context remains to
be done, as highlighted by recent
papers covering what would be basic
Michael Gross is a science writer based at
Oxford. He can be contacted via his web page
at www.michaelgross.co.uk
Who are your scientific heroes? I
should probably say something lofty

Current Biology Vol 22 No 24
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here, but as a young child in the late
1970s I was obsessed with Star Trek,
and so my first scientific hero was
fictional — Spock, science officer on
the starship Enterprise. He embodied
so much of what attracted me to
science; he was inquisitive, logical,
honest, meticulous, calm, fearless in
facing the unknown, innovative and
unafraid of taking risks; science was
exciting on board the Enterprise,
their cutting-edge technology to be
envied. And of course, they adhered
to ‘the prime directive’ which dictates
that there can be no interference
with the internal development of
alien civilizations. My research, while
obviously not concerned with aliens,
has been influenced by this. My desire
to study a cognitive phenomenon or
behaviour such that the examination
of it does not divert it from its natural
course or how it would occur in the
real world, owes much to Starfleet’s
General Order #1.
on how they performed a task, can
provide valuable insights into their
priorities and strategies. Some people
frown upon introspection and regard
experiences. Knowing what research
question to ask is vital. This may seem
obvious, but in cognitive neuroscience
sometimes people can’t see the wood
this information as unreliable, while I on for the trees, and don’t always ask the
the other hand am disappointed when
experimenters don’t include it.
Overall, these ‘heroes’ represent for
me the importance of not being afraid
to address your research question
directly, of availing of information
at multiple levels, combining the
quantitative and the qualitative,
the creative with the assiduously
controlled.
important, the ‘big’ questions. Also, as
alluded to, being brave and trying to
think around the question in new and
interesting ways can be exciting and
illuminating.
For me, and this may not be very
helpful for aspiring researchers, a
key element has been good luck.
The start of my postdoc career
coincided with the rise of functional
neuroimaging, the establishing of the
FIL in London, which also happened to
be recruiting — right place, right time.
I now had starship-like technology to
work with and the chance to apply it to
my research questions. This was only
possible because of the Frith-factor.
Chris Frith hired me as a postdoc to
work on a schizophrenia project. An
administrative delay in accessing
patients saw me filling in time
Do you have a favourite paper? If I
had to pick one, it would be O’Keefe
and Nadel’s 1979 Behavioral and Brain
Sciences paper ‘Précis of O’Keefe
& Nadel’s The Hippocampus as a
Cognitive Map’, which is a summary
of their 1978 book, accompanied
by commentaries from other
neuroscientists. In the early 1990s I
Consequently, my interest in trying to was working as a neuropsychologist
understand how the brain allows us to
navigate in the world and to remember
what happens to us along the way is
underpinned in part by paradigms that
study these behaviours directly. This is
challenging, particularly in the context
of neuroimaging, where people cannot
move their head while being scanned,
and yet we want them to navigate
through the streets and through their
life’s experiences. It requires inventive
approaches such as the use of virtual
reality environments, of multi-voxel
pattern analysis of functional magnetic
resonance imaging (fMRI) data to
detect neural signatures of specific
autobiographical memories, and
careful control conditions to deal with
the complexity of the cognition under
scrutiny. Nevertheless, the judicious
use of naturalistic protocols, where
key neuroscience questions cannot be
addressed effectively in other ways, is
a rewarding and effective pursuit.
My second hero is Wilhelm Wundt,
often regarded as the ‘father of
with patients who were undergoing
temporal lobectomy for the relief of
intractable epilepsy. I was about to
start a PhD studying this cohort, but
was unsure what to focus on. I read
this paper and it cemented everything.
First, it contacted with something
personal, my complete inability to
find my way around, something that
plagues me to this day. Second,
navigation problems were prevalent
among these patients in their everyday
lives, thus affording the opportunity
to study something meaningful. And
third, it opened up the wondrous
world of the hippocampus, with its
exquisite anatomy and physiology, its
clear importance for navigation but
also for episodic memory and, as we
now know, for imagining fictitious and
future experiences. How it manages to
achieve all of this remains the central
question of my research programme.
John O’Keefe was subsequently the
examiner of my PhD, and when I
moved to UCL we had the chance to
collaborate. I’ve benefitted a lot from
his advice (and wonderful anecdotes!),
in particular his encouraging me to
consider the physiological grounding
of the higher cognitive functions that I
continuing my PhD work and doing
a neuroimaging study of navigation. I
never did study schizophrenia. Chris’
generosity, the freedom he gave me to
pursue my own interests, his wisdom,
his diplomacy and the sense of delight
and fun with which he approaches
science were, and are, inspiring — he
should probably be in my heroes
category.
I was also fortunate in that
neuropsychology has numerous
female role-models, including Brenda
Milner, Elizabeth Warrington and Uta
Frith; all of them inspirational and who
meant that, for the most part, it never
occurred to me that gender would
ever be a barrier to success. Finally,
funding, the lifeblood of the research
scientist. Funders who are willing
to take risks, to provide long-term
funding, with a light and facilitatory
touch, who help to protect the scientist
from the rising tide of bureaucracy are
an invaluable ingredient — I have been
very fortunate to benefit from such a
funder in the Wellcome Trust.
modern psychology’. Wundt was
the first to adopt introspection, the
self-examination of one’s conscious
thoughts and feelings, as a legitimate
tool for research. Of course much is
hidden from our awareness, but what is investigate.
not shouldn’t be ignored. Introspecting
has helped me to decompose complex
thoughts and behaviours to make
them amenable to investigation. In
addition, debriefing subjects following
an experiment, having them introspect
Other than that, I have a small
research group; it suits my type of
work, and allows me to stay close to
the data. I also put a lot of effort into
preparing talks; I would say never
underestimate the value of giving a
good talk. This is the most direct way
to communicate one’s science, and be
it a seminar to high-school students,
a public lecture, or a presentation
to experts, everyone enjoys and
What are the ingredients of a
successful research career? Cooking
not being my strong point, I don’t have
a coherent recipe to offer, but merely a
few random observations from my own

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remembers a clear, uncluttered and
coherent story. The final, rather
obvious, ingredient that springs to
mind is hard work. My Mother is fond
of quoting Mark Twain: “Don’t go
around saying the world owes you a
living. The world owes you nothing. It
was here first”.
media/1121995). Horn continued
to study at night school and, after
National Service in the Royal Air
Force, took a medical degree at the
University of Birmingham. That this
was not a foregone conclusion is
illustrated by a rather stern letter
from ‘the Sub-Dean and Tutor’ of the
Medical School that Gabriel always
kept above his desk in his study:
“There is no possibility of you being
accepted here in the near future and
since you have no qualifications
for the medical profession and
competition is very keen, my advice
to you is to abandon the project
altogether for I feel it will only lead
to disappointment.” Thankfully, Horn
persisted, and much later, in 1999,
his alma mater redeemed itself by
awarding him an honorary doctorate.
As a medical student, he already
showed great interest in brain and
cognition, and during a year working
with Solly Zuckerman, Professor
of Anatomy at the University of
Birmingham, he wrote an essay on
‘The Neurological Basis of Thought’
(www.zoo.cam.ac.uk/zoostaff/
Obituary
Sir Gabriel Horn
(1927–2012)
Johan J. Bolhuis1
and Mark H. Johnson2
Do you have any regrets or bugbears?
Like many others I regret not knowing
more maths. Although perhaps I should
be careful what I wish for, as being
more mathematically-savvy might
prevent the occasional leaps of faith
that make the naturalistic aspects of
my research exciting.
In a research career spanning well
over 50 years, Sir Gabriel Horn, who
died on 2nd August this year, saw
the field of neuroscience grow from
infancy to the mature field that we
know today. In the year of his birth,
1927, neuroscience was still a young,
emerging field of rather specialist
interest — it was only 20 years earlier
that Cajal and Golgi had shared
the Nobel Prize for their work on
the basic structure of the nervous
system. Horn’s neuroscientific
contributions consistently pioneered
new approaches and areas of
investigation for others to follow.
Indeed, his work presaged several
active directions of contemporary
research in cognitive and
Bugbears: there’s definitely a few,
but for brevity’s sake I’ll mention
just two. Like everyone else, I find
the peer-review process frustrating
and imperfect, but I don’t have a
credible alternative to offer. Another
frustration is the media. I’m fortunate
that my work engages the interest
of the general public and the media
are a crucial conduit in this process.
However, I sometimes feel a bit like
an aging rock singer, I’m singing
new songs, but the media only want
to hear the old tunes — invariably
about London taxi drivers. I get a lot
of media inquiries and many of them
are lazy, unimaginative, and looking to
sensationalise. Of course this isn’t true
across the board and some science
journalists are well-informed and ask
important questions of academia,
science and scientists. It is vital
that science and the media engage,
but both sides have some way to
go in making it a more fulfilling and
productive relationship.
madingley/library/member_papers/
ghorn/Horn%20Neurological%
20basis%20of%20thought.pdf),
published in a student journal called
‘The Mermaid’. In this paper, Horn
laid the foundations of much of his
later work on the neural basis of
attention, habituation, memory, and
development, and he frequently
developmental neuroscience.
Gabriel Horn attended Handsworth
Technical School in Birmingham, but
he left at 16 to work in his parents’
tailoring business. He spoke very
warmly of his parents in a filmed
interview conducted by Sir Patrick
Bateson (see www.sms.cam.ac.uk/
What are the next big questions in
your field? The questions haven’t
changed. Learning and memory
are so fundamental to us, so
enmeshed throughout cognition,
that ‘solving’ memory, unpacking
its neural mechanisms and being
able to conceptualise it fully will, I
believe, result in revelations across
neuroscience. And once that’s done
(!), the whole point of this endeavour
and the real work, to improve the lot
of the memory-impaired in a rational
and principled way and to inform
education, can begin in earnest.
Wellcome Trust Centre for Neuroimaging,
Institute of Neurology, University College
London, 12 Queen Square, London WC1N
3BG, UK.
E-mail: e.maguire@ucl.ac.uk
Gabriel Horn in India in 1976. Photo courtesy of Lady Horn.