Fermentation of hydrolysate detoxified by pervaporation through block copolymer membranes

Graphical abstract: Fermentation of hydrolysate detoxified by pervaporation through block copolymer membranes

Fermentation of hydrolysate detoxified by pervaporation through block copolymer membranes


The large-scale use of lignocellulosic hydrolysate as a fermentation broth has been impeded due to its high concentration of organic inhibitors to fermentation. In this study, pervaporation with polystyrene-block-polydimethylsiloxane-block-polystyrene (SDS) block copolymer membranes was shown to be an effective method for separating volatile inhibitors from dilute acid pretreated hydrolysate, thus detoxifying hydrolysate for subsequent fermentation. We report the separation of inhibitors from hydrolysate thermodynamically and quantitatively by detailing their concentrations in the hydrolysate before and after detoxification by pervaporation. Specifically, we report >99% removal of furfural and 27% removal of acetic acid with this method. Additionally, we quantitatively report that the membrane is selective for organic inhibitor compounds over water, despite water’s smaller molecular size. Because its inhibitors were removed but its sugars left intact, pervaporation-detoxified hydrolysate was suitable for fermentation. In our fermentation experiments, Saccharomyces cerevisiae strain SA-1 consumed the glucose in pervaporation-detoxified hydrolysate, producing ethanol. In contrast, under the same conditions, a control hydrolysate was unsuitable for fermentation; no ethanol was produced and no glucose was consumed. This work demonstrates progress toward economical lignocellulosic hydrolysate fermentation.



Corresponding authors
Department of Chemical and Biomolecular Engineering, University of California, Berkeley, USA 
E-mail: nbalsara@berkeley.edu ;
Tel: +1 (510) 642-8937
Department of Bioengineering, University of California, Berkeley, USA 
E-mail: aparkin@lbl.gov ;
Tel: +1 (510) 643-5678
Energy Biosciences Institute, University of California, Berkeley, USA
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, USA
Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, USA
Green Chem., 2014, Advance Article

DOI: 10.1039/C4GC00756E











Received 28 Apr 2014, Accepted 24 Jun 2014
First published online 11 Jul 2014

Hydrolysate was pervaporated with a block copolymer membrane, removing inhibitors but leaving sugars, creating a viable fermentation broth.


Chiral Tin Participates in Radical Cyclizations


Chiral tin hydrides generate radicals and transfer chirality in the cyclization of aldehydes
This offers an insight for the future design of catalytic asymmetric radical reactions.

Read more


Rapid Wolff-Kishner reductions in a silicon carbide microreactor

Green Chem., 2013, Advance Article
DOI: 10.1039/C3GC41942H, Paper
Stephen G. Newman, Lei Gu, Christoph Lesniak, Georg Victor, Frank Meschke, Lahbib Abahmane, Klavs F. Jensen
Wolff-Kishner reductions are performed continuously in a silicon carbide microreactor. Short reactions times and safe operation are achieved, giving high yields without reactor corrosion issues using just 1.5 equivalents of hydrazine.

Rapid Wolff-Kishner reductions in a silicon carbide microreactor


Wolff–Kishner reductions are performed in a novel silicon carbide microreactor. Greatly reduced reaction times and safer operation are achieved, giving high yields without requiring a large excess of hydrazine. The corrosion resistance of silicon carbide avoids the problematic reactor compatibility issues that arise when Wolff–Kishner reductions are done in glass or stainless steel reactors. With only nitrogen gas and water as by-products, this opens the possibility of performing selective, large scale ketone reductions without the generation of hazardous waste streams

Branched Enynenynols

“Old MacDonald Named a Compound: Branched Enynenynols”

that was originally published in the J. Chem. Ed. 74 (1997) 782, about what would happen if ‘Old MacDonald’ were a chemist, and made molecules that have the shapes of animals. Some are shown below.


Department of Chemistry, Hofstra University, Hempstead, NY 11590
J. Chem. Educ., 1997, 74 (7), p 782
DOI: 10.1021/ed074p782
Publication Date (Web): July 1, 1997


Selection of boron reagents for Suzuki-Miyaura coupling

Selection of boron reagents for Suzuki-Miyaura coupling

Chem. Soc. Rev.
, 2014, Advance Article
DOI: 10.1039/C3CS60197H, Review Article

Alastair J. J. Lennox, Guy C. Lloyd-Jones
School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK
This review analyses the general physical and chemical properties of the seven main classes of boron reagent that have been employed for SM coupling
Suzuki–Miyaura (SM) cross-coupling is arguably the most widely-applied transition metal catalysed carbon–carbon bond forming reaction to date. Its success originates from a combination of exceptionally mild and functional group tolerant reaction conditions, with a relatively stable, readily prepared and generally environmentally benign organoboron reagent. A variety of such reagents have been developed for the process, with properties that have been tailored for application under specific SM coupling conditions. This review analyses the seven main classes of boron reagent that have been developed. The general physical and chemical properties of each class of reagent are evaluated with special emphasis on the currently understood mechanisms of transmetalation. The methods to prepare each reagent are outlined, followed by example applications in SM coupling.

Improved Continuous Flow Processing: Benzimidazole Ring Formation via Catalytic Hydrogenation of an Aromatic Nitro Compound


Improved Continuous Flow Processing: Benzimidazole Ring Formation via Catalytic Hydrogenation of an Aromatic Nitro Compound

Chemical Process Research and Development, Teva Pharmaceuticals, 383 Phoenixville Pike, Malvern, Pennsylvania 19355, United States
Org. Process Res. Dev., Article ASAP
Publication Date (Web): August 6, 2013 (Article)
DOI: 10.1021/op400179f
 In the development of a new route to bendamustine hydrochloride, the API in Treanda, the key benzimidazole intermediate 5 was generated via catalytic heterogeneous hydrogenation of an aromatic nitro compound using a batch reactor. Because of safety concerns and a site limitation on hydrogenation at scale, a continuous flow hydrogenation for the reaction was investigated at lab scale using the commercially available H-Cube. The process was then scaled successfully, generating kilogram quantities on the H-Cube Midi. This flow process eliminated the safety concerns about the use of hydrogen gas and pyrophoric catalysts and also showed 1200-fold increase in space–time yield versus the batch processing.






DR ANTHONY MELVIN CRASTO, Worlddrugtracker, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his PhD from ICT ,1991, Mumbai, India, in Organic chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with GLENMARK- GENERICS LTD, Research centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Prior to joining Glenmark, he worked with major multinationals like Hoechst Marion Roussel, now sSanofi, Searle India ltd, now Rpg lifesciences, etc. he is now helping millions, has million hits on google on all organic chemistry websites. His New Drug Approvals, Green Chemistry International, Eurekamoments in organic chemistry are some most read blogs He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 25 year tenure, good knowledge of IPM, GMP, Regulatory aspects, he has several international drug patents published worldwide . He gas good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, polymorphism etc He suffered a paralytic stroke in dec 2007 and is bound to a wheelchair, this seems to have injected feul in him to help chemists around the world, he is more active than before and is pushing boundaries, he has one lakh connections on all networking sites, He makes himself available to all, contact him on +91 9323115463, amcrasto@gmail.com

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Systematic name
Other names
1,3-dioxolane, 2-[2,5-bis(3,3-dimethyl-1-butyn-1-yl)-4-[2-(3,5-di-1-pentyn-1-ylphenyl)ethynyl]phenyl]
618904-86-2  cas

NanoPutians are a series of organic molecules whose structural formulae resemble human forms.[1] James Tour et al. (Rice University) designed and synthesized these compounds in 2003 as a part of a sequence of chemical education for young students.[2] The compounds consist of two benzene rings connected via a few carbon atoms as the body, four acetylene units each carrying an alkyl group at their ends which represents the hands and legs, and a 1,3-dioxolane ring as the head. Tour and his team at Rice University used the NanoPutians in their NanoKids educational outreach program. The goal of this program was to educate children in the sciences in an effective and enjoyable manner. They have made several videos featuring the NanoPutians as anthropomorphic animated characters.
Construction of the structures depends on Sonogashira coupling and other synthetic techniques. By replacing the 1,3-dioxolane group with an appropriate ring structure, various other types of putians have been synthesized, e.g. NanoAthlete, NanoPilgrim, and NanoGreenBeret. Placing thiol functional groups at the leg enables them to “stand” on a gold surface.
“NanoPutian” is a portmanteau of nanometer, a unit of length commonly used to measure chemical compounds, and lilliputian, a fictional population of humans in the novel Gulliver’s Travels.


NanoKids Educational Outreach Program]

While there are no chemical uses for the NanoKid or any of its subsidiaries, James Tour has turned the NanoKid into a lifelike character to educate children in the sciences. The goals of the outreach program, as described on the NanoKids website, are:
  • “To significantly increase students’ comprehension of chemistry, physics, biology, and materials science at the molecular level.”
  • “To provide teachers with conceptual tools to teach nanoscale science and emerging molecular technology.”
  • “To demonstrate that art and science can combine to facilitate learning for students with diverse learning styles and interests.”
  • “To generate informed interest in nanotechnology that encourages participation in and funding for research in the field.”[3]
To accomplish these goals, several video clips, CDs, as well as interactive computer programs were created. Tour and his team invested over $250,000 into their project. In order to raise the funds for this endeavor, Tour used unrestricted funds from his professorship and small grants from Rice University, the Welch Foundation, the nanotech firm Zyvex, and Texas A&M University. Tour also received $100,000 in 2002 from the Small Grants for Exploratory Research program, a division of the National Science Foundation.[4]
The main characters in the videos are animated versions of the NanoKid. They star in several videos and explain various scientific concepts, such as the periodic tableDNA, and covalent bonding.
Rice conducted several studies into the effectiveness of using the NanoKids materials. These studies found mostly positive results for the use of the NanoKids in the classroom. A 2004-2005 study in two schools districts in Ohio and Kentucky found that using NanoKids led to a 10-59% increase in understanding of the material presented. Additionally, it was found that 82% of students found that NanoKids made learning science more interesting.[5]

ChemSpider 2D Image | Nanokid | C39H42O2

Synthesis of NanoKid

Upperbody of NanoKid

To create the first NanoPutian, dubbed the NanoKid, 1,4-dibromobenzene was iodinated in sulfuric acid. To this product, “arms”, or 3,3-Dimethylbutyne, were then added through Sonogashira coupling. Formylation of this structure was then achieved through using the organolithium reagent n-butyllithium followed by quenching with N,N-dimethylformamide (DMF) to create the aldehyde. 1,2-Ethanediol was added to this structure to protect the aldehyde using p-toluenesulfonic acid as a catalyst. Originally, Chanteau and Tour aimed to couple this structure with alkynes, but this resulted in very low yields of the desired products. To remedy this, the bromide was replaced withiodide through lithium-halogen exchange and quenching by using 1,2-diiodoethane. This created the final structure of the upper body for the NanoKid.[1]

Lowerbody of NanoKid

The synthesis of NanoPutian’s lower body begins with nitroaniline as a starting material. Addition of Br2 in acetic acid places two equivalents of bromine on the benzene ring. NH2 is an electron donating group, and NO2 is an electron withdrawing group, which both direct bromination to the meta position relative to the NO2 substituent. Addition of [[NaNO2]], [[H2SO4]], and EtOH removes the NH2¬ substituent. The Lewis acid SnCl2, a reducing agent in THF/EtOH solvent, replaces NO2 with NH2, which is subsequently replaced by iodine upon the addition of NaNO2, H2SO4, and KI to yield 3,5-dibromoiodobenzene. In this step, the Sandmeyer reaction converts the primary amino group (NH2) to a diazonium leaving group (N2), which is subsequently replaced by iodine. Iodine serves as an excellent coupling partner for the attachment of the stomach, which is executed through Sonogashira coupling with trimethylsilylacetylene to yield 3,5-dibromo(trimethylsilylethynyl)benzene. Attachment of the legs replaces the Br substituents with 1-pentyne through another Sonogashira coupling to produce 3,5-(1′-Pentynyl)-1-(trimethylsilylethynyl) benzene. To complete the synthesis of the lower body, the TMS protecting group is removed by selective deprotection through the addition of K2CO3, MeOH, and CH2Cl2 to yield 3,5-(1′-Pentynyl)-1-ethynylbenzene.[1]

Attachment of Upperbody to Lowerbody of NanoKid

To attach the upper body of the NanoKid to the lower body, the two components were added to a solution of bis(triphenylphosphine)palladium(II) dichloridecopper(I) iodide,TEA, and THF. This resulted in the final structure of the NanoKid.[1]

Derivatives of NanoKid

Synthesis of NanoProfessionals[]

The series of NanoProfessionals were created using the NanoKid as the starting material. This was done by adding an excess amount of a 1,2- or 1,3- diol to the NanoKid in the presence of a catalytic amount of p-toluenesulfonic acid and microwave oven-irradiation. The use of microwave irradiation reduced the reaction times. These reactions resulted in an acetal exchange, which changed the structure of the head of the NanoKid to create the different head structures of the NanoProfessionals, which include: NanoAthlete, NanoPilgrim, NanoGreenBeret, NanoJester, NanoMonarch, NanoTexan, NanoScholar, NanoBaker, and NanoChef. By creating a series of different figures, the ultimate product was a recognizably diverse population of NanoPutians.[2]
Although the majority of the figures are depicted in their equilibrium conformations, some of the NanoPutians include nonequilibrium conformations in order to make them more recognizable to nonchemists. Many liberties were taken in the visual depiction of the head dressings of the NanoPutians.[2]
The entire population of NanoPutians (with the exception of the NanoChef) were generated in one microwave oven reaction and confirmed by mass spectrometry and 1HNMR.[1]
Below is a table listing the diols needed to convert the NanoKid into various NanoProfessionals. The diols used to create NanoPilgrim and NanoTexan were made through reductive pinacol coupling of the 1,4- and 1,5-diketones with SmI2 and Mg/TiCl4. To create the diols used to make the NanoMonarch and the NanoScholar, catalytic OsO4 was used to dihydroxylate the respective cycloalkenes. The diastereomeric ratios were determined through 1H NMR using the diastereotopic acetal protons.[1]

Synthesis of the NanoKid in Upright Form]

Stick Figure NanoPutian in its Energy Minimized Conformation. Determined Using Spartan.

3-Butyn-1-ol was reacted with methanesulfonyl chloride and triethanolamine to produce its mesylate. The mesylate was displaced to make thiolacetate. The thiol was coupled with 3,5-dibromo(trimethylsilylethynyl)benzene to create a free alkyne. The resulting product, 3,5-(4’-thiolacetyl-1’-butynyl)-1-(trimethylsilylethynyl)-benzene, had its trimethylsilyl group removed using tetra-n-butylammonium fluoride (TBAF) and AcOH/Ac2O in THF. The free alkyne was then coupled with the upper body product from the earlier synthesis. This resulted in a NanoKid with protected thiol feet.[1]
To make the NanoKid “stand’, the acetyl protecting groups were removed through the use of ammonium hydroxide in THF to create the free thiols. A gold-plated substrate was then dipped into the solution and incubated for four days. Ellipsometry was used to determine the resulting thickness of the compound, and it was determined that the NanoKid was upright on the substrate.[1]

Synthesis of NanoPutian Chain

Synthesis of the upper part of the NanoPutian chain begins with 1,3-dibromo-2,4-diiodobenzene as the starting material. Sonogashira coupling with 4-oxytrimethylsilylbut-1-yne produces 2,5-bis(4-tert-butyldimethylsiloxy-1′-butynyl)-1,4-di-bromobenzene. One of the bromine substituents is converted to an aldehyde through an SN2 reaction with the strong base, n-BuLi, and THF in the aprotic polar solvent, DMF to produce 2,5-bis(4-tert-butyldimethylsiloxy-1′-butynyl)-4-bromobenzaldehyde. Another Sonogashira coupling with 3,5-(1′-Pentynyl)-1-ethynylbenzene attaches the lower body of the NanoPutian. The conversion of the aldehyde group to a diether “head” occurs in two steps. The first step involves addition of ethylene glycol and trimethylsilyl chloride (TMSCl) in CH2Cl2 solvent. Addition of TBAF in THF solvent removes the silyl protecting group.[1]


  1. a b c d e f g h i Chanteau, S. H.; Tour, J. M. (2003). “Synthesis of Anthropomorphic Molecules:  The NanoPutians”The Journal of Organic Chemistry 68 (23): 8750–8766.doi:10.1021/jo0349227PMID 14604341edit
  2. a b c Chanteau, S. H.; Ruths, T.; Tour, J. M. (2003). “Arts and Sciences Reunite in Nanoput: Communicating Synthesis and the Nanoscale to the Layperson”Journal of Chemical Education 80 (4): 395. doi:10.1021/ed080p395edit
  3. ^ “Welcome to Nanokids.” Accessed May 6, 2013. http://nanokids.rice.edu/.
  4. ^ “C&EN: EDUCATION – ‘NANOKIDS’ TRY TO GET INTO MIDDLE SCHOOL.” Accessed May 10, 2013. http://pubs.acs.org/cen/education/8214/8214nanokids.html.
  5. ^ “NanoKids – Mission.” Accessed May 6, 2013. http://cohesion.rice.edu/naturalsciences/nanokids/mission.cfm?doc_id=3039.

External link


In 2003, there was a paper published which looked like it was going to be a good candidate for the Ig Nobel Prize. It was “Synthesis of Anthropomorphic Molecules: The NanoPutians” by Professor James Tour, a chemistry professor at Rice University’s Institute for Nanoscale Science and Technology. The word “NanoPutian” is a portmanteau of “nano”, which means a billionth and the “Lilliputian” from the novel Gulliver’s Travels.
The Tour group designed and synthesized a number of human-shaped organic molecules in this paper. Shown in Figure 1 is a molecule named NanoKid, which was chosen by the group as a basic skeleton. The 3-D model looks like the figure on the right and the structural formula used by chemists is shown on the left. The structural formula might look more human, since the oxygen atoms look kind of like the eyes.

Fig 1 NanoKid

The functional group used for the head part of NanoKid is called acetal. This group is easily exchangeable to make NanoPutians of various occupations (Figure 2). Let’s not be too picky about the bond angles of NanoMonarch and NanoTexan.

Fig 2 various NanoPutians

Unfortunately, NanoBalletDancer seems to be the only one having a different posture (Figure 3). Personally, I would be interested in making NanoPitcher or NanoGermanSuplex!

Fig 3 NanoBalletDancer

The Tour Group also synthesized NanoPutians standing on gold surface with thiol functional groups on their feet, a NanoPutian couple dancing (Figure 4), and even a polymer of NanoPutians (Figure 5).

Fig 4 NanoPutian Couple

Fog 5 NanoPutian polymer

NanoPutians aren’t actually the first example of human-shaped molecule. For example, the molecule shown in Figure 6 has appeared as a joke in a journal published on April Fool’s Day. The molecule shown in Figure 7 has been introduced once as Buddha molecule. Nevertheless, NanoPutians were probably the first case where human-shaped molecules were synthesized systematically(?) to be published as a full paper.

Fig 6 human-shaped molecule Fig 7 molecular Buddha

The Role of NanoPutians
Besides being human-shaped, the NanoPutian molecules have neither notable properties nor potential usefulness for future. The synthesis is also too straightforward to make any significant methodological contribution to chemical science.
Then how did this research get funded and get to be published on Journal of Organic Chemistry? It turns out that the synthesis was a part of the chemistry education program at Rice University aimed at introducing nanotechnology to young students. In fact, it has also been on the cover page of Journal of Chemical Education too. It’s funny though, to imagine the faces of the journal editors when they first read the paper.
But come to think of it, molecules like dodecahedrane and kekulene might not be so different in terms of not having much to appeal other than their structural beauty. Even “total synthesis of biologically active natural products”, the most respected subfield of organic chemistry, has been criticized on its meaning recently. In a way, the NanoPutian research seems to me as a voice saying “synthetic targets should be selected more freely” and almost as an antithesis against the state of organic chemistry today.

Anyway, this paper was introduced by general media and was also one of the topics that received most feedbacks on my homepage. There were those who dismissed it as a meaningless play by chemists, but in terms of directing public interest toward organic chemistry wasn’t it a hundred times more effective than ordinary researches? I think it was an excellent work for the education of young chemists as well.
Professor Tour’s playful sense of molecular design can be seen in his research of NanoCars too, which I will introduce in a separate column. This is a wonderful work which can impress both serious scientists and general public.




– See more at: http://organicchemistrysite.blogspot.in/#sthash.KDZiGxlJ.dpuf

Iodine-mediated arylation of benzoxazoles with aldehydes

A simple and efficient methodology for the arylation of benzoxazoles with aldehydes using iodine as the mediator has been developed. The reaction proceeded smoothly with a range of substrates to give the corresponding arylated products in moderate to good yields


Green Chem., 2013, 15,2365-2368
DOI: 10.1039/C3GC41027G, Communication
Corresponding authors
Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore
E-mail: ygzhang@ibn.a-star.edu.sg ;
Fax: (+65) 6478-9020

A simple and efficient methodology for the arylation of benzoxazoles with aldehydes using iodine as the mediator has been developed