Design and Synthesis of Novel Squaraine-Based Fluorescent Probe for Far-Red Detection of Chymotrypsin Enzyme.

Chymotrypsin, a crucial enzyme in human digestion, catalyzes the breakdown of milk proteins, underscoring its significance in both health diagnostics and dairy quality assurance. Addressing the critical need for rapid, cost-effective detection methods, we introduce a groundbreaking approach utilizing far-red technology and HOMO-Förster resonance energy transfer (FRET). Our novel probe, SQ-122 PC, features a unique molecular design that includes a squaraine dye (SQ), a peptide linker, and SQ moieties synthesized through solid-phase peptide synthesis. Demonstrating a remarkable quenching efficiency of 93.75% in a tailored H2O:DMSO (7:3) solvent system, our probe exhibits absorption and emission properties within the far-red spectrum, with an unprecedented detection limit of 0.130 nM. Importantly, our method offers unparalleled selectivity towards chymotrypsin, ensuring robust and accurate enzyme detection. This pioneering work underscores the immense potential of far-red-based homo-FRET systems in enabling the sensitive and specific detection of chymotrypsin enzyme activity. By bridging the gap between cutting-edge technology and biomedical diagnostics, our findings herald a new era of enzyme sensing, promising transformative advancements in disease diagnosis and dairy quality control.

Anti-cancer activity of heteroaromatic acetals of andrographolide and its isomers.

Acetals (2a-d, 3a-d, and 6a-d) of andrographolide (1), 14-deoxy-12-hydroxyandrographolide (4), and isoandrographolide (5) were synthesized using benzaldehyde and heteroaromatic aldehydes. All the synthesized derivatives were characterized using 1H-NMR, 13C-NMR, mass spectrometry, UV, and IR. The compound 6d was characterized via a single-crystal X-ray diffraction study. All the compounds were tested against 60 cell lines of NCI. The acetals (2a-d) of andrographolide (1) exhibited better activity than the acetals (3a-d, and 6a-d) of 12-hydroxyandrographolide (4) and isoandrographolide (5). Preliminary studies suggested that acetals synthesized using benzaldehyde improved anticancer activity. Compound 2a showed the highest growth inhibition of 90.97% against the leukaemia cancer cell line CCRF-CEM. Andrographolide and seven selected compounds were tested against the MDA-MB-231 breast cancer cell line. Compound 3b showed the best activity with an IC50 value of 3 µM among all the tested compounds. Furthermore, this compound 3b was subjected to cell cycle analysis and protein expression confirming apoptosis through the disruption of the mitochondrial potential membrane (Δψ m).

Synthesis of novel spirobibenzopyrans as potent anticancer leads inducing apoptosis in HeLa cells.

Spirobibenzopyrans are an unexplored class of therapeutics. We report the anticancer activity of novel spirobibenzopyrans, synthesized by a one-pot reaction and extensively characterized. Structure of one of the spirobibenzopyran has been determined by the single crystal XRD technique. The in vitro anticancer activity of these derivatives across the NCI 60-cell line panel was evaluated and for the first time their mechanism of action against HeLa cells was probed via cell morphology analysis and cell cycle analysis. They were determined to be apoptosis inducers with cell cycle arrest in G0/G1 and S phase suggesting CDK-4 protein inhibition and the inhibition of DNA replication. The DNA inhibition was studied and confirmed using the alkaline comet assay for the compound CHX-4MO-SAL showing S phase inhibition. Further, conformity with the in silico Lipinski's score signify the potential of spirobibenzopyrans as anticancer leads.