Allylation of p-ketoaldehydes and functionalized imines by diallyltin dibromide: formation of skipped and conjugated dienes

Diallyltin dibromide reacts with β-keto-aldehydes possessing no aromatic side groups and with (hydroxy) aryl imines to afford the expected homoallyl alcohols or amines respectively. With β-ketoaldehydes having aromatic side groups, skipped or conjugated dienes are obtained depending on whether or not an aqueous work up procedure is used

Cyclic chlorophosphites as scaffolds for the one-pot synthesis of α-aminophosphonates under solvent-free conditions

New α-aminophosphonates of the type (OCH2CMe2CH2O)P(O)CH(NHCO2R)(R') [6a-i, 7a-e, and 8a-c] have been synthesized in high yields by a three-component reaction using (OCH2CMe2CH2O)PCl (3), benzamide (or urethane or benzyl carbamate), and an aldehyde without using any catalyst under solvent-free conditions. This route can be readily adapted for bis-aminophosphonates as well as optically active binaphthoxy α-aminophosphonates; it also tolerates the phenolic -OH group as shown by the synthesis of hydroxy functionalized aminophosphonates. Partial hydrolysis of compounds 7a-d leads to products in which the phosphorinane ring is cleaved first. Compounds (OCH2CMe2CH2O)P(O)CH[NHC(O)Ph](9-anthryl) (6f) and optically pure (R,S)-(-)-(C20H12O2)P(O)CH(NHCO2Et)(Ph) (14a) were characterized by X-ray crystallography

EFFECT OF GEMCITABINE ON FEMALE FERTILTY – AN ANIMAL MODEL STUDY

Background and objectives: Advances in cancer chemotherapy have led to improved survival rates and poses greater emphasis on preserving quality of life post-treatment. Gonadotoxicity is a well-recognized side effect of many cancer chemotherapeutic agents. This study was designed to evaluate the effects of gemcitabine, an antimetabolite anticancer drug, on oogenesis in Swiss albino mice and its reversibility. Methods: Thirty six inbred female Swiss albino mice in diestrous phase were selected and divided into three groups of twelve each. Groups were labelled as A, B and Control. Groups A and B received 40 mg/kg and 80 mg/kg of gemcitabine intraperitoneally. The control group received saline intraperitoneally. At the end of two weeks 6 mice were sacrificed from each group and the rest at the end of 2 months.  Ovaries were studied histologically. Results: After 2 weeks, the ovaries of experimental group mice showed more number of atretic follicles as compared to control group (p<0.01). The diameter of corpus lutea was more, though a reduction in number was recorded in experimental group (p<0.05).  Whereas after 2 months, both the experimental groups showed no difference in terms of atretic follicles, diameter and number of corpus lutea (p>0.05). Conclusions: These findings suggest that administration of gemcitabine may have profound effects on oogenesis and hence female fertility. This study also suggests that the effects are reversible. Keywords: Gemcitabine; Oogenesis; Swiss albino mice; atretic follicles; corpus luteum

Selenium biochemistry and its role for human health

Despite its very low level in humans, selenium plays an important and unique role among the (semi)metal trace essential elements because it is the only one for which incorporation into proteins is genetically encoded, as the constitutive part of the 21st amino acid, selenocysteine. Twenty-five selenoproteins have been identified so far in the human proteome. The biological functions of some of them are still unknown, whereas for others there is evidence for a role in antioxidant defence, redox state regulation and a wide variety of specific metabolic pathways. In relation to these functions, the selenoproteins emerged in recent years as possible biomarkers of several diseases such as diabetes and several forms of cancer. Comprehension of the selenium biochemical pathways under normal physiological conditions is therefore an important requisite to elucidate its preventing/therapeutic effect for human diseases. This review summarizes the most recent findings on the biochemistry of active selenium species in humans, and addresses the latest evidence on the link between selenium intake, selenoproteins functionality and beneficial health effects. Primary emphasis is given to the interpretation of biochemical mechanisms rather than epidemiological/observational data. In this context, the review includes the following sections: (1) brief introduction; (2) general nutritional aspects of selenium; (3) global view of selenium metabolic routes; (4) detailed characterization of all human selenoproteins; (5) detailed discussion of the relation between selenoproteins and a variety of human diseases

A spirocyclic tetraoxyphosphorane with an apically located chlorine in a trigonal bipyramid and its hydrolysis product

The spirocyclic (chloro)tetraoxyphosphorane CH2(6-t-Bu-4-Me-C6H2O)2P(Cl)(1,2-O2C6Cl4) (2) and its hydrolysis product CH2(6-t-Bu-4-Me-C6H2O)2P(O)(OC6Cl4-2-OH) (3) have been synthesized and characterized by X-ray crystallography and solution state NMR. Unlike the previously reported spirocyclic chlorophosphoranes where chlorine occupies an equatorial position of a trigonal bipyramid (TBP), in 2 it is apical. The hydrolysis product 3 is a hydrogen bonded dimer. Compound CH2(6-t-Bu-4-Me-C6H2O)2P(Cl)[1,2-O2-3,5-(t-Bu)2C6H2] (4) was also synthesized in a manner analogous to that of 2. Attempts to isolate structurally characterizable pentacoordinate compounds by reacting CH2(6-t-Bu-4-Me-C6H2O)2PX [X=Cl (1), 2,6-Cl2C6H3O (5), cycl-C6H11NH (6)] with N-chlorodiisopropylamine were not successful, although in some cases a pentacoordinate species was detected; the corresponding oxidized products CH2(6-t-Bu-4-Me-C6H2O)2P(O)X [X=Cl (7), 2,6-Cl2C6H3O (8), cycl-C6H11NH (9)] were isolated by this route. Variable temperature (1H, 31P) NMR spectra of 2 have been recorded; at low temperatures, two 31P NMR signals of unequal intensity are seen in the pentacoordinate region. A probable intramolecular process involving equatorial-equatorial↔apical<->equatorial (for the eight-membered ring) has been invoked to explain the spectral features

A convenient route to aryl substituted chloro and bromo olefins

A wide range of aryl substituted chloro and bromo olefins has been prepared by treating α-chloro and α-bromophosphonates derived from 1-hydrido-5,5-dimethyl-1,3,2-dioxaphosphorinane with sodium hydride in THF at 0°C followed by an aldehyde

Study of clinical and aetiological pattern of anterior uveitis in middle Karnataka

Background and Objectives: Uveitis, a complex intraocular inflammatory disease results from several aetiological entities. The cause of inflammation might be infectious agent or trauma, but in most cases the underlying mechanism appears to be autoimmune in nature. Anterior uveitis is most common form of uveitis and accounts for an annual incidence rate of about 17 cases/1,00,000 population. Objective of this study is to evaluate the aetiological pattern, treatment and its outcome and complications of anterior uveitis. Methods: A prospective clinical study was done in the Department of Ophthalmology, Karnataka during December 2012 to May 2014. All patients between 20 and 80 years of age clinically presenting with anterior uveitis were studied. A thorough clinical evaluation followed by investigations was done to determined aetiology. Patients were put on specific and nonspecific treatment and were followed up for a period of 6 months. Complications were noted. Results: The aetiology of uveitis remained unknown in most cases (42%). Most common cause was observed to be blunt trauma (20%) followed by phacolytic (12%). Most cases responded well to treatment. Commonest complication was posterior persistent synechiae (23.64%), and cataract was the second common (14.54%). Interpretation and Conclusion: Aetiological diagnosis remains undetermined in majority of cases. A thorough examination and investigation are required in each case to facilitate a final diagnosis. Prompt treatment ensures good visual outcome. Ocular morbidity is common in chronic and recurrent cases

Characterization of stereoisomers of spirophosphoranes bearing an eight-membered ring: implications on apicophilicity in trigonal bipyramidal phosphorus

This article does not have an abstract

An easy access to trisubstituted vinyl chlorides and improved synthesis of chloro/bromostilbenes

The α-chlorophosphonates (OCH2CMe2CH2O)P(O)CHCl-C6H4-4-R [R=H (4), Me (5), OMe (6)], which are now readily accessible, react with ketones R'C(O)R" in the presence of NaH (without recourse to the more expensive t-BuLi) to afford trisubstituted vinyl halides R'C(R")=CCl(C6H4-4-R) in good yields. The corresponding α-bromophosphonates [R=H (7), Me (8)] failed to react with ketones and gave the symmetrical acetylenes 4-R-C6H4-C≡C-C6H4-4-R as isolable products in low yield. We have found that K2CO3 in refluxing xylene is a good base for the synthesis of chlorostilbenes; using this base the bromostilbenes ArCH=CBr(C6H4-4-R) can be prepared in significantly higher yields than by using NaH. The stereochemistry of two of the trisubstituted vinyl chlorides is unambiguously proven by X-ray structure determination. Thus for (Cl)PhC=CPh(Me), the isomer with the upfield NMR shift for the CH3 protons and for (Cl)PhC=C(Ph)(C6H4-4-Me), the isomer with the downfield NMR shift for the -C6H4-4-CH3 protons have Z stereochemistry

Direct synthesis of α-substituted phosphonates

The α-substituted phosphonates (OCH2CMe2CH2O)P(O)CH(X)(Ar) [X=Cl, OMe, NMe2 and OSiMe3], useful precursors for Horner-Wadsworth-Emmons reactions, are readily prepared by treating (OCH2CMe2CH2O)PX with an aromatic aldehyde. In the reaction of (OCH2CMe2CH2O)PCl with furfuraldehyde and cinnamaldehyde, the 5-chlorofurfurylphosphonate (OCH2CMe2CH2O)P(O)CH2(5-Cl-C4H2O) and the γ-chlorophosphonate (OCH2CMe2CH2O)P(O)CH=CH-CH(Cl)Ph, respectively, are formed in good yields