nan Shagufta

Recent developments in steroidal and nonsteroidal aromatase inhibitors for the chemoprevention of estrogen-dependent breast cancer

Aromatase, a cytochrome P450 enzyme complex present in breast tissues, plays a significant role in the biosynthesis of important endogenous estrogens from androgens. The source of estrogen production in breast cancer tissues is intra-tumoral aromatase, and inhibition of aromatase may inhibit the growth stimulation effect of estrogens in breast cancer tissues. Consequently, aromatase is considered a useful therapeutic target in the treatment and prevention of estrogen-dependent breast cancer. Recently, different natural products and synthetic compounds have been rapidly developed, studied, and evaluated for aromatase inhibitory activity. Aromatase inhibitors are classified into two categories on the basis of their chemical structures, i.e., steroidal and nonsteroidal aromatase inhibitors. This review highlights the synthetic steroidal and nonsteroidal aromatase inhibitors reported in the literature in the last few years and will aid medicinal chemists in the design and synthesis of novel and pharmacologically-potent aromatase inhibitors for the treatment of breast cancer.

Recent insight into the biological activities of synthetic xanthone derivatives.

Xanthones are a class of oxygen containing heterocyclic compounds with a broad range of biological activities, and they have prominent significance in the field of medicinal chemistry. Xanthone is an attractive scaffold for the design and development of new drugs due to its promising biological activities, primarily as anticancer, antimalarial, antimicrobial, anti-HIV, anticonvulsant, anticholinesterase, antioxidant, anti-inflammatory, and as inhibitors of several enzymes like α-glycosidase, topoisomerase, protein kinase, aromatase, etc. In this review, we have compiled and discussed recent developments on the pharmacological profile of synthetic xanthone derivatives for different therapeutic targets. The review highlights the therapeutic significance of xanthones and offers support in the development of new xanthone derivatives as therapeutic agents.

A new example of a steroid–amino acid hybrid: construction of constrained nine membered D-ring steroids

A new archetype of steroid-amino acid hybrids containing a nine membered D-ring with hetero atoms has been synthesized for the first time from estrone and amino acids by using Yamaguchi coupling reactions.

Synthetic approach towards trisubstituted methanes and a chiral tertiary α-hydroxyaldehyde, a possible intermediate for tetrasubstituted methanes

A series of trisubstituted methanes containing aryl and heteroaryl rings, as well as a sulfur spacer between the central methano-carbon and benzene ring, is reported. In an approach towards asymmetric tetrasubstituted methane with high enantioselectivity, chiral tertiary α-hydroxyaldehyde has been synthesized through a Sharpless dihydroxylation on a disubstituted olefin, followed by the chemoselective oxidation of the primary alcohol.

Sulfonic Acid-Functionalized Solid Acid Catalyst in Esterification and Transesterification Reactions

The recent development of an environmentally benign solid acid catalyst has been a relatively cutting-edge area of research in the synthesis of value added esters and biodiesel. Solid acid catalysts are economically viable, effective, and environmentally amicable than conventional homogeneous catalysts and reusability of the catalyst is another advantage of these catalysts. The applicability of sulfonic acid-functionalized solid acid catalysts in the well-known esterification and transesterification reactions for the synthesis of esters and biodiesel, respectively along with their reusability aspect are discussed in this review.

Advances in asymmetric oxidative kinetic resolution of racemic secondary alcohols catalyzed by chiral Mn(III) salen complexes

Enantiomerically pure secondary alcohols are essential compounds in organic synthesis and are used as chiral auxiliaries and synthetic intermediates in the pharmaceutical, agrochemical, and fine chemical industries. One of the attractive and practical approaches to achieving optically pure secondary alcohols is oxidative kinetic resolution of racemic secondary alcohols using chiral Mn(III) salen complexes. In the last decade, several chiral Mn(III) salen complexes have been reported with excellent enantioselectivity and activity in the homogeneous and heterogeneous catalysis of the oxidative kinetic resolution of racemic secondary alcohols. This review article is an overview of the literature on the recent development of chiral Mn(III) salen complexes for oxidative kinetic resolution of racemic secondary alcohols. The catalytic activity of monomeric, dimeric, macrocyclic, polymeric, and silica/resin supported chiral Mn(III) salen complexes is discussed in detail.

Quest for steroidomimetics: Amino acids derived steroidal and nonsteroidal architectures

The chiral pool amino acids have been utilized for the construction of steroidal and non-steroidal architectures in the quest for steroidomimetics. Chirality derived from amino acid-based architectures provides new and easy to incorporate chiral chemical space, which is otherwise very difficult to introduce and comprised of several synthetic steps for asymmetric steroids. The different and exciting ligand-receptor interactions may arise from the use of each amino acid enantiomer that was introduced into the chiral steroidal backbone. The A and D rings of steroidal architectures can be mimicked by the phenyl group of the amino acid tyrosine. The Mitsunobu reaction, nucleophilic substitution and elimination, etc. were utilized for constructing diverse tri- and tetracyclic steroidal skeletons as well as benzofused seco-steroids from amino acids. These benzofused, amino acid-derived steroidal and nonsteroidal molecules had promising biological activity in hormonal related disorders.