Harnessing the anti-cancer potential of linamarin: A computational study on design and hydrolysis mechanisms of its derivatives.

Cassava extracts containing cyanogenic compounds demonstrate anticancer properties. The cyanogenic glucoside linamarin found abundantly in cassava can release hydrogen cyanide (HCN) upon hydrolysis, a potent cytotoxin. However, linamarin's hydrolysis mechanism by human enzymes is poorly delineated and constitutes a bottleneck for therapeutic development. This study aimed to investigate linamarin's hydrolysis mechanism by human ß-glucosidase and identify structural derivatives with enhanced hydrolytic potential using density functional theory calculations. Results revealed α-anomeric derivatives as promising, with leaving group ability and steric bulk strongly governing hydrolysability. We identified several linamarin analogs with predicted rapid hydrolysis kinetics that may enable swift cytotoxic HCN release against cancer cells. This investigation enriches understanding of cyanogenic glycoside reactivity to facilitate their development as targeted antineoplastic agents. The identified derivatives set the groundwork for experimental evaluation of enhanced linamarin-inspired compounds as innovative cancer therapeutics.

Practical and scalable synthesis of beclomethasone dipropionate.

Beclomethasone dipropionate (1) is a synthetic corticosteroid with anti-inflammatory, antipruritic, and anti-allergy properties. It is widely used to treat asthma, allergic rhinitis, and dermatoses. However, existing synthetic routes to this active pharmaceutical ingredient (API) contain steps resulting in low and/or inconsistent yields, and use obsolete reagents. Such inconsistencies coupled with a lack of reliable experimental data makes laboratory-scale and large-scale synthesis of this API difficult and time-consuming. In this paper, we report a practical and scalable approach to synthesize 1 from the readily available steroidal intermediate, 16ß-methyl epoxide (3, DB-11). A gram-scale to kilogram-scale synthesis of 1 was achieved with 82% yield, using a cost-effective and scalable methodology. Selective propionylation of the hydroxyl groups at C17 and C21 demonstrate the fact that this approach can be conveniently implemented in fine chemical industries.

Updating Levothyroxine Synthesis for the Modern Age.

Synthesis of levothyroxine sodium, the sodium salt of a synthetic levoisomer of thyroxine, revolutionized the management of hypothyroidism and related symptoms. However, the primary synthetic route to this active pharmaceutical ingredient (API) is more than 70+ years old with low-yielding steps and obsolete reagents. It lacks experimental data on intermediates, making laboratory and large-scale synthesis of this API difficult and time-consuming. Here, we describe an improved synthesis of levothyroxine using commonly available modern reagents. By modifying and replacing low yielding and/or unproductive steps of Chalmers synthesis, we were able to achieve higher overall yields (39-51%) consistently. Key modifications include an alternative path to the selective N-acetylation step that yielded 5 in a pure and consistent fashion. Our improved methodology, coupled with detailed experimental data, provides a practical alternative to existing methods that can be conveniently implemented to synthesize Levothyroxine sodium in fine chemical settings.

An efficient and high-yielding method for extraction and purification of linamarin from Cassava; in vitro biological evaluation.

During the last three decades, studies of linamarin extracted from cassava have received increased attention due to the presence of high cyanogenic compounds in these extracts. The methods that are utilized to isolate linamarin are either tedious or use acidic conditions resulting in poor yields. In this study, a novel cryocooled method of extraction has been developed to isolate linamarin from Cassava root peel. Approximately 18 g of linamarin was isolated from 1 kg of fresh Cassava root peel, which is the highest amount reported to date. Linamarin was fully characterized using NMR, IR and LCMS. The anti-cancer properties of pure linamarin and Cassava crude extract were evaluated by a comprehensive cytotoxic assay, using MCF-7, HepG2, NCI H-292, AN3CA and MRC-5 cell lines. The crude extract showed higher cytotoxicity compared to pure linamarin. The results of the biological evaluation are comparable to other reported studies in the literature.

Mature leaf concentrate of Sri Lankan wild type Carica papaya Linn. modulates nonfunctional and functional immune responses of rats.

BACKGROUND: The leaf concentrate of Carica papaya is a traditionally acclaimed immunomodulatory remedy against numerous diseases; nonetheless comprehensive scientific validation of this claim is limited. The present study thus investigated the immunomodulatory potential of Carica papaya mature leaf concentrate (MLCC) of the Sri Lankan wild type cultivar using nonfunctional and functional immunological assays. METHODS: Wistar rats (N = 6/ group) were orally gavaged with 3 doses (0.18, 0.36 and 0.72 ml/100g body weight) of the MLCC once daily for 3 consecutive days. Selected nonfunctional (enumeration of immune cells and cytokine levels) and functional (cell proliferation and phagocytic activity) immunological parameters, and acute toxic effects were determined using standard methods. Effect of the MLCC (31.25, 62.5, 125, 250, 500 and 1000 µg/ml) on ex vivo proliferation of bone marrow cells (BMC) and splenocytes (SC), and in vitro phagocytic activity of peritoneal macrophages (PMs), and their corresponding cytokine responses were evaluated. The phytochemical profile of the MLCC was established using liquid chromatography-mass spectrometry (LS-MS) and Gas chromatography-mass spectrometry (GC-MS). RESULTS: Counts of rat platelets, total leukocytes, lymphocyte and monocyte sub populations, and BMCs were significantly augmented by oral gavage of the MLCC (p < 0.05). The highest MLCC dose tested herein significantly reduced pro inflammatory cytokines, Interleukin 6 (IL-6) and Tumor Necrosis Factor α (TNF α) levels of rats (p < 0.05). The in vivo phagocytic index of rat PMs significantly increased by oral gavage of all three doses of the MLCC (p < 0.05). In vitro phagocytic activity of rat PMs were enhanced by the MLCC and triggered a Th1 biased cytokine response. The MLCC at low concentrations elicited ex vivo proliferation of BMC (31.25 µg/ml) and SC (31.25 and 62.5 µg/ml) respectively. Conversely, high concentrations (500 and 1000 µg/ml) exhibited cytotoxicity of both BMC and SC with significant modulation of cytokines. Chemical profile of the MLCC revealed the presence of several immunomodulatory compounds. The oral gavage of the MLCC was found to be safe in terms of both hepatic and renal toxicities. CONCLUSION: The present study established that the mature leaf concentrate (MLCC) of Carica papaya Sri Lankan wild type cultivar is orally active, safe and effectively modulates nonfunctional and functional immunological parameters of rats that unequivocally corroborate the traditional medical claims.

Mechanistic Insight into Receptor-Mediated Delivery of Cationic-ß-Cyclodextrin:Hyaluronic Acid-Adamantamethamidyl Host:Guest pDNA Nanoparticles to CD44(+) Cells.

Targeted delivery is a key element for improving the efficiency and safety of nonviral vectors for gene therapy. We have recently developed a CD44 receptor targeted, hyaluronic acid-adamantamethamidyl based pendant polymer system (HA-Ad), capable of forming complexes with cationic ß-cyclodextrins (CD-PEI(+)) and pDNA. Complexes formed using these compounds (HA-Ad:CD-PEI(+):pDNA) display high water solubility, good transfection efficiency, and low cytotoxicity. Spatial and dynamic tracking of the transfection complexes by confocal microscopy and multicolor flow cytometry techniques was used to evaluate the target specificity, subcellular localization, and endosomal escape process. Our data shows that cells expressing the CD44 receptor undergo enhanced cellular uptake and transfection efficiency with HA-Ad:CD-PEI(+):pDNA complexes. This transfection system, comprised noncovalent assembly of cyclodextrin:adamantamethamidyl-modified hyaluronic acid via host:guest interactions to condense pDNA, is a potentially useful tool for targeted delivery of nucleic acid therapeutics.

Effect of pendant group on pDNA delivery by cationic-ß-cyclodextrin:alkyl-PVA-PEG pendant polymer complexes.

We have previously shown that cationic-ß-cyclodextrin:R-poly(vinyl alcohol)-poly(ethylene glycol) (CD+:R-PVA-PEG) pendant polymer host:guest complexes are safe and efficient vehicles for nucleic acid delivery, where R = benzylidene-linked adamantyl or cholesteryl esters. Herein, we report the synthesis and biological performance of a family of PVA-PEG pendant polymers whose pendant groups have a wide range of different affinities for the ß-CD cavity. Cytotoxicity studies revealed that all of the cationic-ß-CD:pendant polymer host:guest complexes have 100-1000-fold lower toxicity than branched polyethylenimine (bPEI), with pDNA transfection efficiencies that are comparable to bPEI and Lipofectamine 2000. Complexes formed with pDNA at N/P ratios greater than 5 produced particles with diameters in the 100-170 nm range and ζ-potentials of 15-35 mV. Gel shift and heparin challenge experiments showed that the complexes are most stable at N/P ≥ 10, with adamantyl- and noradamantyl-modified complexes displaying the best resistance toward heparin-induced decomplexation. Disassembly rates of fluoresceinated-pDNA:CD(+):R-PVA-PEG-rhodamine complexes within HeLa cells showed a modest dependence on host:guest binding constant, with adamantyl-, noradamantyl-, and dodecyl-based complexes showing the highest loss in FRET efficiency 9 h after cellular exposure. These findings suggest that the host:guest binding constant has a significant impact on the colloidal stability in the presence of serum and cellular uptake efficiency, whereas endosomal disassembly and transfection performance of cationic-ß-CD:R-poly(vinyl alcohol)-poly(ethylene glycol) pendant polymer complexes appears to be controlled by the hydrolysis rates of the acetal grafts onto the PVA main chain.