ÌÇÐÄvlog¹Ù·½Èë¿Ú

Graphical abstract:

Graphical abstract:

Biorefineries play a vital role in reducing dependence on fossil fuels and addressing global warming concerns. Unfortunately, investment in biorefineries remains limited due to economic sustainability concerns. One approach to enhance the economic viability of biorefineries is by fully utilizing the potential of feedstocks, particularly lignocellulosic biomass, which is commonly used in these processes. Traditional processing methods often alter the lignin portion of biomass, making it unsuitable for further utilization. However, when retained in its native form, lignin can serve as a valuable source of chemicals that contribute to the economic sustainability of biorefineries.

The lignin-first approach, which removes lignin from the cellulosic portion before biofuel conversion, allows for the recovery of value-added chemicals from lignin and enhances the sustainability of biorefineries. One common method for implementing this approach is organosolv, which removes the lignin from biomass. This research developed an organosolv pretreatment method to isolate syringaresinol (S-β-β'-S), a lignin-derived dimer with various biomedical and industrial applications, from oak sawdust as the source biomass. The method incorporated a heat treatment step to increase syringaresinol yields, and key treatment parameters were optimized for maximum output. This approach was then applied to other biomass types: hardwood, softwood, and grass. Poplar and hemp were identified as alternative sources of syringaresinol. The method also revealed the presence of several other potential value-added compounds in the biomass types investigated.

Additionally, this research established a linear retention index (LRI) for the gas chromatographic (GC) analysis of 25 common lignin-derived monomers and dimers, which are frequently detected in biomass chromatograms after pretreatments like organosolv. LRI values are independent of column characteristics, enabling unambiguous identification of analytes and ensuring reproducibility in experimental results. These calculated values were validated with a second GC system. The LRI facilitates the identification and confirmation of compounds without the need for mass spectrometric (MS) analysis, allowing for comparison of chromatographic results across multiple GC systems and aiding in the prediction of retention times for these compounds.

While extracting value-added compounds like syringaresinol from biomass is the first step, recovering them from complex reaction mixtures presents additional challenges. This study explored the use of cyclodextrins (CDs) as potential recovery materials for syringaresinol. CDs are conical molecules with a hydrophilic exterior and a hydrophobic cavity, which can selectively capture lignans through guest-host complex interactions. Initial high-performance liquid chromatography (HPLC) analysis with a commercial β-CD column revealed that lignans, particularly syringaresinol and pinoresinol interact more strongly with β-CD than with most other monomeric lignin decomposition products. Furthermore, the study suggested that γ-CD might be a better recovery material for syringaresinol compared to β-CD. To test this hypothesis, a modified frontal analysis continuous capillary electrophoresis (FACCE) method was developed and validated as an inexpensive, simple approach to estimate the binding constants of lignans to CDs. The FACCE method provided insights into the interactions between lignans and CDs, facilitating the selection of the potentially suitable CD-type for recovery.

Biorefineries play a vital role in reducing dependence on fossil fuels and addressing global warming concerns. Unfortunately, investment in biorefineries remains limited due to economic sustainability concerns. One approach to enhance the economic viability of biorefineries is by fully utilizing the potential of feedstocks, particularly lignocellulosic biomass, which is commonly used in these processes. Traditional processing methods often alter the lignin portion of biomass, making it unsuitable for further utilization. However, when retained in its native form, lignin can serve as a valuable source of chemicals that contribute to the economic sustainability of biorefineries.

The lignin-first approach, which removes lignin from the cellulosic portion before biofuel conversion, allows for the recovery of value-added chemicals from lignin and enhances the sustainability of biorefineries. One common method for implementing this approach is organosolv, which removes the lignin from biomass. This research developed an organosolv pretreatment method to isolate syringaresinol (S-β-β'-S), a lignin-derived dimer with various biomedical and industrial applications, from oak sawdust as the source biomass. The method incorporated a heat treatment step to increase syringaresinol yields, and key treatment parameters were optimized for maximum output. This approach was then applied to other biomass types: hardwood, softwood, and grass. Poplar and hemp were identified as alternative sources of syringaresinol. The method also revealed the presence of several other potential value-added compounds in the biomass types investigated.

Additionally, this research established a linear retention index (LRI) for the gas chromatographic (GC) analysis of 25 common lignin-derived monomers and dimers, which are frequently detected in biomass chromatograms after pretreatments like organosolv. LRI values are independent of column characteristics, enabling unambiguous identification of analytes and ensuring reproducibility in experimental results. These calculated values were validated with a second GC system. The LRI facilitates the identification and confirmation of compounds without the need for mass spectrometric (MS) analysis, allowing for comparison of chromatographic results across multiple GC systems and aiding in the prediction of retention times for these compounds.

While extracting value-added compounds like syringaresinol from biomass is the first step, recovering them from complex reaction mixtures presents additional challenges. This study explored the use of cyclodextrins (CDs) as potential recovery materials for syringaresinol. CDs are conical molecules with a hydrophilic exterior and a hydrophobic cavity, which can selectively capture lignans through guest-host complex interactions. Initial high-performance liquid chromatography (HPLC) analysis with a commercial β-CD column revealed that lignans, particularly syringaresinol and pinoresinol interact more strongly with β-CD than with most other monomeric lignin decomposition products. Furthermore, the study suggested that γ-CD might be a better recovery material for syringaresinol compared to β-CD. To test this hypothesis, a modified frontal analysis continuous capillary electrophoresis (FACCE) method was developed and validated as an inexpensive, simple approach to estimate the binding constants of lignans to CDs. The FACCE method provided insights into the interactions between lignans and CDs, facilitating the selection of the potentially suitable CD-type for recovery.

The Department of ÌÇÐÄvlog¹Ù·½Èë¿Ú hosts an annual Graduation Celebration and Awards Ceremony to recognize the outstanding achievements of our students on an annual basis.

We invite families and friends of graduates and award winners to join us in celebrating the success of these outstanding students. A reception will be held after the ceremony. 

To view this year's brochure, click here. For past events, click here.

College of Arts and Sciences Awards

Outstanding Teaching Assistant in the Department of ÌÇÐÄvlog¹Ù·½Èë¿Ú | Shuvo Deb Nath

Graduate Student Awards

100% Plus Award | Lateefat Jimoh

Outstanding Graduate Student Research Award | Kathryn Pitton

Outstanding Teaching Assistant Award | Md Tawabur Rahman & Motunrayo Oladele

William D. Ehmann Graduate Award Fund in ÌÇÐÄvlog¹Ù·½Èë¿Ú | Shickshitha Dissanayake

C.H.H. Griffith Outstanding General ÌÇÐÄvlog¹Ù·½Èë¿Ú TA Award | Deborah Adeyemi-Alabi & Alexander Igwebuike

Fast Start Award | Joy Jerome

Undergraduate Student Awards

100% Plus Award | Lauren Gravatte

Hammond Undergraduate Service Award | Walter Kunnmann

Hammond Leadership Award | Shasanka Lamichhane

Nancy J. Stafford Award | Mason Marrs

Willard R. Meredith Memorial Award | Marissa Harris

First-Year ÌÇÐÄvlog¹Ù·½Èë¿Ú Major Award | Isabella Soon

General ÌÇÐÄvlog¹Ù·½Èë¿Ú Excellence Award (Spring 2024) | Thomas Lockhart, Elizabeth Scheetz & Caralea Vest

General ÌÇÐÄvlog¹Ù·½Èë¿Ú Excellence Award (Fall 2024) | Harsh Patel & Lauren Marksbury

Undergraduate Scholarships

Wilbur L. Price Scholarship | Daani Karim

The Department of ÌÇÐÄvlog¹Ù·½Èë¿Ú hosts an annual Graduation Celebration and Awards Ceremony to recognize the outstanding achievements of our students on an annual basis.

We invite families and friends of graduates and award winners to join us in celebrating the success of these outstanding students. A reception will be held after the ceremony. 

To view this year's brochure, click here. For past events, click here.

College of Arts and Sciences Awards

Outstanding Teaching Assistant in the Department of ÌÇÐÄvlog¹Ù·½Èë¿Ú | Shuvo Deb Nath

Graduate Student Awards

100% Plus Award | Lateefat Jimoh

Outstanding Graduate Student Research Award | Kathryn Pitton

Outstanding Teaching Assistant Award | Md Tawabur Rahman & Motunrayo Oladele

William D. Ehmann Graduate Award Fund in ÌÇÐÄvlog¹Ù·½Èë¿Ú | Shickshitha Dissanayake

C.H.H. Griffith Outstanding General ÌÇÐÄvlog¹Ù·½Èë¿Ú TA Award | Deborah Adeyemi-Alabi & Alexander Igwebuike

Fast Start Award | Joy Jerome

Undergraduate Student Awards

100% Plus Award | Lauren Gravatte

Hammond Undergraduate Service Award | Walter Kunnmann

Hammond Leadership Award | Shasanka Lamichhane

Nancy J. Stafford Award | Mason Marrs

Willard R. Meredith Memorial Award | Marissa Harris

First-Year ÌÇÐÄvlog¹Ù·½Èë¿Ú Major Award | Isabella Soon

General ÌÇÐÄvlog¹Ù·½Èë¿Ú Excellence Award (Spring 2024) | Thomas Lockhart, Elizabeth Scheetz & Caralea Vest

General ÌÇÐÄvlog¹Ù·½Èë¿Ú Excellence Award (Fall 2024) | Harsh Patel & Lauren Marksbury

Undergraduate Scholarships

Wilbur L. Price Scholarship | Daani Karim

The Department of ÌÇÐÄvlog¹Ù·½Èë¿Ú hosts an annual Graduation Celebration and Awards Ceremony to recognize the outstanding achievements of our students on an annual basis.

We invite families and friends of graduates and award winners to join us in celebrating the success of these outstanding students. A reception will be held after the ceremony. 

To view this year's brochure, click here. For past events, click here.

College of Arts and Sciences Awards

Outstanding Teaching Assistant in the Department of ÌÇÐÄvlog¹Ù·½Èë¿Ú | Shuvo Deb Nath

Graduate Student Awards

100% Plus Award | Lateefat Jimoh

Outstanding Graduate Student Research Award | Kathryn Pitton

Outstanding Teaching Assistant Award | Md Tawabur Rahman & Motunrayo Oladele

William D. Ehmann Graduate Award Fund in ÌÇÐÄvlog¹Ù·½Èë¿Ú | Shickshitha Dissanayake

C.H.H. Griffith Outstanding General ÌÇÐÄvlog¹Ù·½Èë¿Ú TA Award | Deborah Adeyemi-Alabi & Alexander Igwebuike

Fast Start Award | Joy Jerome

Undergraduate Student Awards

100% Plus Award | Lauren Gravatte

Hammond Undergraduate Service Award | Walter Kunnmann

Hammond Leadership Award | Shasanka Lamichhane

Nancy J. Stafford Award | Mason Marrs

Willard R. Meredith Memorial Award | Marissa Harris

First-Year ÌÇÐÄvlog¹Ù·½Èë¿Ú Major Award | Isabella Soon

General ÌÇÐÄvlog¹Ù·½Èë¿Ú Excellence Award (Spring 2024) | Thomas Lockhart, Elizabeth Scheetz & Caralea Vest

General ÌÇÐÄvlog¹Ù·½Èë¿Ú Excellence Award (Fall 2024) | Harsh Patel & Lauren Marksbury

Undergraduate Scholarships

Wilbur L. Price Scholarship | Daani Karim

The Department of ÌÇÐÄvlog¹Ù·½Èë¿Ú hosts an annual Graduation Celebration and Awards Ceremony to recognize the outstanding achievements of our students on an annual basis.

We invite families and friends of graduates and award winners to join us in celebrating the success of these outstanding students. A reception will be held after the ceremony. 

To view this year's brochure, click here. For past events, click here.

College of Arts and Sciences Awards

Outstanding Teaching Assistant in the Department of ÌÇÐÄvlog¹Ù·½Èë¿Ú | Shuvo Deb Nath

Graduate Student Awards

100% Plus Award | Lateefat Jimoh

Outstanding Graduate Student Research Award | Kathryn Pitton

Outstanding Teaching Assistant Award | Md Tawabur Rahman & Motunrayo Oladele

William D. Ehmann Graduate Award Fund in ÌÇÐÄvlog¹Ù·½Èë¿Ú | Shickshitha Dissanayake

C.H.H. Griffith Outstanding General ÌÇÐÄvlog¹Ù·½Èë¿Ú TA Award | Deborah Adeyemi-Alabi & Alexander Igwebuike

Fast Start Award | Joy Jerome

Undergraduate Student Awards

100% Plus Award | Lauren Gravatte

Hammond Undergraduate Service Award | Walter Kunnmann

Hammond Leadership Award | Shasanka Lamichhane

Nancy J. Stafford Award | Mason Marrs

Willard R. Meredith Memorial Award | Marissa Harris

First-Year ÌÇÐÄvlog¹Ù·½Èë¿Ú Major Award | Isabella Soon

General ÌÇÐÄvlog¹Ù·½Èë¿Ú Excellence Award (Spring 2024) | Thomas Lockhart, Elizabeth Scheetz & Caralea Vest

General ÌÇÐÄvlog¹Ù·½Èë¿Ú Excellence Award (Fall 2024) | Harsh Patel & Lauren Marksbury

Undergraduate Scholarships

Wilbur L. Price Scholarship | Daani Karim

Gold(I) complexes typically bond in a linear fashion; however, an increased valence can be achieved via ligand modulation. The most prevalent therapeutic gold complex, auranofin, contains a linear Au(I) center and has shown great potential in several diseases and conditions. On the other hand, the potential of three-coordinate Au(I) complexes have scarcely been probed as therapeutics. Reported here are the synthesis, characterization, and applications of novel three-coordinate Au(I) complexes. The degree of asymmetry varies between complexes depending on the Au-X ancillary ligands. This insight suggests that the degree of asymmetry influences the potency when incubated in various cancer cell lines. In addition, the coordination of bidentate phenanthroline ligand derivatives effect the symmetry by inducing varying degrees of distortion in the crystal structure. When the center Au(I) is bound to an N-Heterocyclic Carbene (NHC), the compound shifts from a distorted trigonal planar geometry to a distorted linear geometry. These complexes were used to probe glioblastoma, an aggressive head-and-neck cancer. When the center Au(I) is bound to biaryl dialkyl phosphine ligands, the geometry varies in symmetry, but the distorted trigonal planar geometry remains intact. Structure activity relationship studies were performed on these complexes in triple negative breast cancer cell lines. Previous research shows a disruption of mitochondrial dynamics when cancer cells were treated with three-coordinate Au(I) complexes, and the novel Au(I)-NHC library indeed disrupts mitochondrial dynamics. Mitochondria are the main energy production centers in the cell and are desirable therapeutic targets due to their implication in aging, inflammation, and cancer. The Au(I)-P library shows little mitochondrial disruption; instead, these complexes induce significant stress in the endoplasmic reticulum. The endoplasmic reticulum transports and folds proteins that allow the cell to function properly and synthesizes lipids and cholesterols. When the endoplasmic reticulum undergoes stress, the several signaling pathways, known as the unfolded protein response, activate, which can lead to lipid accumulation. Both a disruption of mitochondrial dynamics and an induction of endoplasmic reticulum stress can lead to apoptotic cell death. These effects were characterized by several in vitro and in vivo experiments. 

Carboranes are electron-delocalized clusters containing as few as five and as many as fourteen boron and carbon atoms, the majority of which contain two cage carbons. The carbons in the cluster can be easily functionalized with alkyl and aryl phosphines for coordination to metal complexes. Described here is the synthesis of phosphine-functionalized carborane (DPPCb) containing three-coordinate Au(I) complexes. Taken as a whole, this work expands on the current three-coordinate gold(I) libraries and evaluates their in vitro and in vivo biological efficacy.

Gold(I) complexes typically bond in a linear fashion; however, an increased valence can be achieved via ligand modulation. The most prevalent therapeutic gold complex, auranofin, contains a linear Au(I) center and has shown great potential in several diseases and conditions. On the other hand, the potential of three-coordinate Au(I) complexes have scarcely been probed as therapeutics. Reported here are the synthesis, characterization, and applications of novel three-coordinate Au(I) complexes. The degree of asymmetry varies between complexes depending on the Au-X ancillary ligands. This insight suggests that the degree of asymmetry influences the potency when incubated in various cancer cell lines. In addition, the coordination of bidentate phenanthroline ligand derivatives effect the symmetry by inducing varying degrees of distortion in the crystal structure. When the center Au(I) is bound to an N-Heterocyclic Carbene (NHC), the compound shifts from a distorted trigonal planar geometry to a distorted linear geometry. These complexes were used to probe glioblastoma, an aggressive head-and-neck cancer. When the center Au(I) is bound to biaryl dialkyl phosphine ligands, the geometry varies in symmetry, but the distorted trigonal planar geometry remains intact. Structure activity relationship studies were performed on these complexes in triple negative breast cancer cell lines. Previous research shows a disruption of mitochondrial dynamics when cancer cells were treated with three-coordinate Au(I) complexes, and the novel Au(I)-NHC library indeed disrupts mitochondrial dynamics. Mitochondria are the main energy production centers in the cell and are desirable therapeutic targets due to their implication in aging, inflammation, and cancer. The Au(I)-P library shows little mitochondrial disruption; instead, these complexes induce significant stress in the endoplasmic reticulum. The endoplasmic reticulum transports and folds proteins that allow the cell to function properly and synthesizes lipids and cholesterols. When the endoplasmic reticulum undergoes stress, the several signaling pathways, known as the unfolded protein response, activate, which can lead to lipid accumulation. Both a disruption of mitochondrial dynamics and an induction of endoplasmic reticulum stress can lead to apoptotic cell death. These effects were characterized by several in vitro and in vivo experiments. 

Carboranes are electron-delocalized clusters containing as few as five and as many as fourteen boron and carbon atoms, the majority of which contain two cage carbons. The carbons in the cluster can be easily functionalized with alkyl and aryl phosphines for coordination to metal complexes. Described here is the synthesis of phosphine-functionalized carborane (DPPCb) containing three-coordinate Au(I) complexes. Taken as a whole, this work expands on the current three-coordinate gold(I) libraries and evaluates their in vitro and in vivo biological efficacy.