Synthesis and Pharmacological Properties of Modified A- and D-Ring in Dehydroepiandrosterone (DHEA): A Review.

Dehydroepiandrosterone (3β-hydroxyandrost-5-en-17-one) (DHEA) is a naturally occurring steroid hormone primarily produced in the zona reticularis of the human adrenal glands. It serves as a crucial precursor for sex hormones, such as testosterone, estradiol, and androstenedione. Recent findings indicate that DHEA serves as the primary source of sex steroids in women during both pre- and postmenopausal stages.

Inhibition of protein misfolding and aggregation by steroidal quinoxalin-2(1H)-one and their molecular docking studies.

A series of D-ring fused 16-substituted steroidal quinoxalin-2(1H)-one attached to an electron-releasing (ER) or electron-withdrawing (EW) groups via steroidal oxoacetate intermediate were synthesized to investigate their protein aggregation inhibition potential using human lysozyme (HLZ). The influence of the type of substituent at the C-6 positions of the quinoxalin-2(1H)-one ring on the protein aggregation inhibition potential was observed, showing that the EW moiety improved the protein aggregation inhibition potency. Of all the evaluated compounds, NO-substituted quinoxalin-2(1H)-one derivative 13 was the most active compound and had a maximum protein aggregation inhibition effect.

Microwave-assisted one-pot multicomponent synthesis of steroidal pyrido[2,3-d]pyrimidines and their possible implications in drug development.

Protein misfolding can lead to fibrillar and non-fibrillar deposits which are the signs of countless human diseases. A promising strategy for the prevention of such diseases is the inhibition of protein aggregation, and the most crucial step toward effective prevention is the development of small molecules having the potential for protein-aggregation inhibition. In this search, a series of novel steroidal pyrido[2,3-d]pyrimidines have been synthesized employing steroidal ketone, substituted aldehydes, and 2,6-diaminopyrimidin-4(3H)-one through the microwave-assisted one-pot multicomponent methodology.

Investigating Chaperone like Activity of Green Silver Nanoparticles: Possible Implications in Drug Development.

Protein aggregation and amyloidogenesis have been associated with several neurodegenerative disorders like Alzheimer's, Parkinson's etc. Unfortunately, there are still no proper drugs and no effective treatment available. Due to the unique properties of noble metallic nanoparticles, they have been used in diverse fields of biomedicine like drug designing, drug delivery, tumour targeting, bio-sensing, tissue engineering etc.

Green synthesis of silver nanoparticles, its characterization, and chaperone-like activity in the aggregation inhibition of α-chymotrypsinogen A.

Consumption of silver nanoparticles (AgNPs) has been increased many folds due to its antimicrobial actions resulting in its widespread incorporation into a wide range of biomedical and consumer products. Still, enough research is needed to clearly understand the effect of these nanoparticles on the conformations of important macromolecules like proteins under different pathophysiological conditions. Pointing towards the situation, we carefully designed an in vitro study to elucidate the effect of green AgNPs on the aggregation pattern of α-chymotrypsinogen A at a human pathological body temperature.

Thermal unfolding of human lysozyme induces aggregation: Recognition of the aggregates by antisera against the native protein.

Protein aggregates are formed due to the inappropriate folding of polypeptides. Human lysozyme (HLZ) plays an important role in the innate immune response of the body and has been used extensively as a model protein to study aggregation. In this study, we showed that HLZ undergoes unfolding induced aggregation when heated by using spectroscopic and microscopic techniques.

A Biophysical and Computational Study of Concanavalin A Immobilized Zinc Oxide Nanoparticles.

Background: Con A, a lectin extract from jackbean Canavalia ensiformis is known for its agglutination activity. ZnO nanoparticles promote the faster electron transfer between the lectin immobilized and the target cells. Hence, Con A immobilized on ZnO nanoparticles will agglutinate cells more effectively than the native protein.

Serotonin abrogates dopamine induced aggregation of cytochrome c.

Importance of cytochrome c arises from its involvement in apoptosis, sequence homology and conserveness during molecular evolution. Dopamine at 25μM concentration for 30h resulted in cytochrome c aggregation as evident by increase in ANS and ThT binding, structural transition from α helix to β sheet and shift in congo red assay. Interestingly, serotonin at 25μM concentration incubated for 60h abrogates the aggregatory effect on cytochrome c.

Aloe emodin, an anthroquinone from Aloe vera acts as an anti aggregatory agent to the thermally aggregated hemoglobin.

Aggregation of proteins is a physiological process which contributes to the pathophysiology of several maladies including diabetes mellitus, Huntington's and Alzheimer's disease. In this study we have reported that aloe emodin (AE), an anthroquinone, which is one of the active components of the Aloe vera plant, acts as an inhibitor of hemoglobin (Hb) aggregation. Hb was thermally aggregated at 60°C for four days as evident by increased thioflavin T and ANS fluorescence, shifted congo red absorbance, appearance of β sheet structure, increase in turbidity and presence of oligomeric aggregates.

Peroxidase improves the activity of catalase by preventing aggregation during TFE-induced denaturation.

Catalase, a ubiquitous enzyme of the free radical scavenging machinery unfolds and aggregates in the presence of 2,2,2-triflouroethanol (TFE). Catalase molecule aggregates at 50% TFE as evident by high thioflavin T fluorescence, shifted congo red absorbance, change in circular dichroism and soret spectra. TEM images confirmed the nature of catalase aggregates to be oligomers.

Aggregation as a consequence of glycation: insight into the pathogenesis of arthritis.

Advanced glycation end products (AGEs) as a result of Maillard reaction are currently at the heart of the pathogenesis of several diseases and hence are the objective of numerous investigations. Glycation of proteins has been an implication in long-term complications. Collagen is the most abundant protein in the human body.