Commercial-scale biotherapeutics manufacturing facility for plant-made pharmaceuticals.

Rapid, large-scale manufacture of medical countermeasures can be uniquely met by the plant-made-pharmaceutical platform technology. As a participant in the Defense Advanced Research Projects Agency (DARPA) Blue Angel project, the Caliber Biotherapeutics facility was designed, constructed, commissioned and released a therapeutic target (H1N1 influenza subunit vaccine) in <18 months from groundbreaking. As of 2015, this facility was one of the world's largest plant-based manufacturing facilities, with the capacity to process over 3500 kg of plant biomass per week in an automated multilevel growing environment using proprietary LED lighting.

Determination of antiplasmodial activity and binding affinity of curcumin and demethoxycurcumin towards PfTrxR.

In our study, the inhibitory activity of curcuminoids towards Plasmodium falciparum thioredoxin reductase (PfTrxR) was determined using LC-MS-based functional assay and showed that only demethoxycurcumin (DMC) inhibited PfTrxR (IC50: 2 μM). In silico molecular modelling was used to ascertain and further confirm that the binding affinities of curcumin and DMC are towards the dimer interface of PfTrxR. The in vitro antiplasmodial activities of curcumin and DMC were evaluated and shown to be active against chloroquine (CQ)-sensitive (D6 clone) and moderately active against CQ-resistant (W2 clone) strains of Plasmodium falciparum while no cytotoxicity was observed against Vero cells.

Characterization of PfTrxR inhibitors using antimalarial assays and in silico techniques.

Background: The compounds 1,4-napthoquinone (1,4-NQ), bis-(2,4-dinitrophenyl)sulfide (2,4-DNPS), 4-nitrobenzothiadiazole (4-NBT), 3-dimethylaminopropiophenone (3-DAP) and menadione (MD) were tested for antimalarial activity against both chloroquine (CQ)-sensitive (D6) and chloroquine (CQ)-resistant (W2) strains of Plasmodium falciparum through an in vitro assay and also for analysis of non-covalent interactions with P. falciparum thioredoxin reductase (PfTrxR) through in silico docking studies.

Results: The inhibitors of PfTrxR namely, 1,4-NQ, 4-NBT and MD displayed significant antimalarial activity with IC50 values of < 20 μM and toxicity against 3T3 cell line.

Determination of antiplasmodial activity and binding affinity of selected natural products towards PfTrxR and PfGR.

In our study, the binding affinities of selected natural products towards PfTrxR, PfGR, human TrxR and human GR were determined using a mass spectrometry based ligand binding assay. The in vitro antimalarial activity and cytotoxicity of these ligands were also determined. Catharanthine, 11-(OH)-coronaridine, hernagine, vobasine and hispolone displayed antiplasmodial activity against PfK1 (IC50 = 0.

Development of liquid chromatography/mass spectrometry based screening assay for PfTrxR inhibitors using relative quantitation of intact thioredoxin.

Rationale: Plasmodium falciparum (Pf) thioredoxin reductase (TrxR) catalyzes the reduction of thioredoxin disulfide (Trx-S(2)) to thioredoxin dithiol (Trx-(SH)(2)) that is essential for antioxidant defense mechanism and DNA synthesis in the parasite and is a validated drug target for new antimalarial agents.

Methods: In this study, we have developed a liquid chromatography/mass spectrometry (LC/MS)-based functional assay to identify inhibitors of PfTrxR by quantifying the product formed (Trx-(SH)(2)) in the enzymatic reaction. Relative quantitation of the reaction product (intact Trx-(SH)(2)) was carried out using an Agilent 6520 QTOF mass spectrometer equipped with a positive mode electrospray ionization (ESI) source.

Identification of oleamide in Guatteria recurvisepala by LC/MS-based Plasmodium falciparum thioredoxin reductase ligand binding method.

Our current research on applications of mass spectrometry to natural product drug discovery against malaria aims to screen plant extracts for new ligands to Plasmodium falciparum thioredoxin reductase (PfTrxR) followed by their identification and structure elucidation. PfTrxR is involved in the antioxidant defense and redox regulation of the parasite and is validated as a promising target for therapeutic intervention against malaria. In the present study, detannified methanol extracts from Guatteria recurvisepala, Licania kallunkiae, and Topobea watsonii were screened for ligands to PfTrxR using ultrafiltration and liquid chromatography/mass spectrometry-based binding experiments.

Screening of natural compounds for ligands to PfTrxR by ultrafiltration and LC-MS based binding assay.

In our study, we have screened 133 structurally diverse natural compounds from the MEGx® collection of AnalytiCon Discovery and three synthetic hispolone analogs for binding affinity to Plasmodium falciparum thioredoxin reductase (PfTrxR) using an ultrafiltration (UF) and liquid chromatography (LC/MS) based ligand-binding assay newly developed in our laboratory. PfTrxR catalyzes the reduction of thioredoxin (PfTrx) protein. In reduced form, PfTrx is essentially involved in the antioxidative defense and redox regulation of P.