Synthesis and skin gene analysis of 4'-acetoxy-resveratrol (4AR), therapeutic potential for dermal applications.

Resveratrol (RV) 1, a plant polyphenol, has proven effective in commercial products yet drawbacks include low bioavailability due to rapid metabolism. Structural modifications have led to a 4'-acetoxy analog 2 (4AR) now produced using a selective one-step esterification reaction. The one-step synthesis is shown together with expression of skin genes using human dermal models to establish 4AR 2 benefits to skin health. 4AR 2 at 1% in qPCR experiments using a human skin model significantly increased gene expression of the anti-aging factor, SIRT 1 by over 3.3-fold, extracellular matrix proteins collagen III, IV, elastin and tissue inhibitors of metalloproteinases (TIMP 1, 2), anti-oxidants CAT, LOX, superoxide dismutase (SOD 1, 2), metallothioneins (MT1H, MT1H), skin aging biomarkers fibrillin (FBN1), laminin (LAMB1), proliferating cell nuclear antigen (PCNA), skin growth factors (HBEGF, IGF1, NGF and TGF). 4AR 2 also decreased gene expression of inflammatory and skin-aging molecules (IL-1, IL-6, IL-8, COX-2, TNGRSF) and S100 calcium binding proteins A8, A9. These findings suggest that 4AR 2 has potential for topically treatment and prevention of skin aging.

Gibbs Energy of Superoxide Dismutase Heterodimerization Accounts for Variable Survival in Amyotrophic Lateral Sclerosis.

The exchange of subunits between homodimeric mutant Cu, Zn superoxide dismutase (SOD1) and wild-type (WT) SOD1 is suspected to be a crucial step in the onset and progression of amyotrophic lateral sclerosis (ALS). The rate, mechanism, and ΔG of heterodimerization (ΔGHet) all remain undetermined, due to analytical challenges in measuring heterodimerization. This study used capillary zone electrophoresis to measure rates of heterodimerization and ΔGHet for seven ALS-variant apo-SOD1 proteins that are clinically diverse, producing mean survival times between 2 and 12 years (postdiagnosis). The ΔGHet of each ALS variant SOD1 correlated with patient survival time after diagnosis (R(2) = 0.98), with more favorable ΔGHet correlating with shorter survival by 4.8 years per kJ. Rates of heterodimerization did not correlate with survival time or age of disease onset. Metalation diminished the rate of subunit exchange by up to ∼38-fold but only altered ΔGHet by <1 kJ mol(-1). Medicinal targeting of heterodimer thermodynamics represents a plausible strategy for prolonging life in SOD1-linked ALS.

Voltage-Induced Misfolding of Zinc-Replete ALS Mutant Superoxide Dismutase-1.

The monomerization of Cu, Zn superoxide dismutase (SOD1) is an early step along pathways of misfolding linked to amyotrophic lateral sclerosis (ALS). Monomerization requires the reversal of two post-translational modifications that are thermodynamically favorable: (i) dissociation of active-site metal ions and (ii) reduction of intramolecular disulfide bonds. This study found, using amide hydrogen/deuterium (H/D) exchange, capillary electrophoresis, and lysine-acetyl protein charge ladders, that ALS-linked A4V SOD1 rapidly monomerizes and partially unfolds in an external electric field (of physiological strength), without loss of metal ions, exposure to disulfide-reducing agents, or Joule heating. Voltage-induced monomerization was not observed for metal-free A4V SOD1, metal-free WT SOD1, or metal-loaded WT SOD1. Computational modeling suggested a mechanism for this counterintuitive effect: subunit macrodipoles of dimeric SOD1 are antiparallel and amplified 2-fold by metal coordination, which increases torque at the dimer interface as subunits rotate to align with the electric field.

A new synthesis of 4'-resveratrol esters and evaluation of the potential for anti-depressant activity.

The 4'-ester analog of the disease preventative resveratrol 1 (RV), 4'-acetyl-RV 2 along with 4'-pivaloate 13 and benzoate 14 RV were synthesized. The previously developed palladium catalyzed decarbonylative Heck coupling was used to assemble the stilbene core together with 3,5-dibenzyl protected phenol intermediates that allowed for efficient coupling and deprotection using boron trifluoride etherate. Studies with Long-Evans rats were performed to establish safety, toxicity, and behavioral parameters. In addition, the Porsalt forced-swim test was used to demonstrate anti-depressant activity.