P. Ramachandra Reddy

Synthesis, antimicrobial and cytotoxic activities of pyrimidinyl benzoxazole, benzothiazole and benzimidazole.

A variety of pyrimidinyl benzoxazoles, benzothiazoles and benzimidazoles linked by thio, methylthio and amino moieties were prepared and studied their antimicrobial and cytotoxic activities. The compound pyrimidinyl bis methylthio benzimidazole 22 was a potent antimicrobial agent particularly against Staphylococcus aureus (29 mm, MIC 12.5 μg/mL) and Penicillium chrysogenum (38 mm, MIC 12.5 μg/mL). The amino linked pyrimidinyl bis benzothiazole 24 exhibited cytotoxic activity on A549 cells with IC50 value of 10.5 μM.

INVOLVEMENT OF METHYL FARNESOATE IN THE REGULATION OF MOLTING AND REPRODUCTION IN THE FRESHWATER CRAB OZIOTELPHUSA SENEX SENEX

Abstract The influence of methyl farnesoate (MF) in the regulation of molt and gonad development in the crab Oziotelphusa senex senex was investigated. Injection of methyl farnesoate into female and male crabs significantly (P < 0.0001) increased mean oocyte diameter (236.37%) and testicular follicle diameter (25.72%) as well as mean gonad indices (females 1304.35%; males 38.00%) and also accelerated the molting (females 80%; males 100%). These results provide strong evidence that methyl farnesoate is involved in the control of both molting and reproduction in crabs.

In vitro methyl farnesoate secretion by mandibular organs isolated from different molt and reproductive stages of the crab Oziotelphusa senex senex

Considerable evidences indicate that mandibular organ (MO) of crustaceans secrete terpenoid hormone (methyl farnesoate [MF]), which regulates molting and reproduction. In the freshwater south Indian rice field crab Oziotelphusa senex senex, MO isolated during premolt and vitellogenesis, secreted greater amounts of MF, which indicates that the regulation of the crustacean molt and reproduction is complex and also involves MF, besides steroid (ecdysteroid) and peptide (sinus gland peptide) hormones.

Mandibular organ: it's relation to body weight, sex, molt and reproduction in the crab, Oziotelphusa senex senex Fabricius (1791)

The dynamics of the mandibular organ (MO) in the edible fresh water field crab Oziotelphusa senex senex was studied as a function of sex, weight, reproduction, molting and eyestalk ablation (ESX). The weight of the mandibular organ exhibited a positive correlation with the body weight. In general, male crabs possess larger mandibular organs when compared to female crabs. The weight of the mandibular organ increased with ovarian index, molting and as the crab progressed towards reproduction. Bilateral eyestalk ablation resulted in a significant increase in mandibular organ weight. The methyl farnesoate (MF) content of the mandibular organ increased with increase in organ weight. The results presented strongly support a potential role of the mandibular organ in regulating both molting and reproduction.

Impairment of male reproduction in adult rats exposed to hydroxyprogesterone caproate in utero

Hydroxyprogesterone caproate is one of the most effective and widely used drugs for the treatment of uterine bleeding and threatened miscarriage in women. Hydroxyprogesterone caproate was administered to pregnant rats in order to assess the effect of intraperitoneal exposure to supranormal levels of hydroxyprogesterone caproate on the male reproductive potential in the first generation. The cauda epididymal sperm count and motility decreased significantly in rats exposed to hydroxyprogesterone caproate during embryonic development, when compared with control rats. The levels of serum testosterone decreased with an increase in follicle stimulating hormone and luteinizing hormone in adult rats exposed to hydroxyprogesterone caproate during the embryonic stage. It was suggested that the impairment of male reproductive performance could be mediated through the inhibition of testosterone production.

Purification of molt-inhibiting hormone-like peptides with hyperglycemic activity from the eyestalks of the crab Scylla serrata

In the present study, putative molt-inhibiting hormone (MIH)-like peptides from the sinus glands of Scylla serrata (S. serrata) were characterized by high-performance liquid chromatography, followed by immunoassay and bioassay (inhibition of ecdysteroid synthesis by Y-organs). Results of double immunodiffusion demonstrated the cross-reactivity of Homarus americanus MIH antiserum with the S. serrata MIH-like peptides, indicating the existence of close immunological relationship between crab and lobster peptides. Of the three molt-inhibiting immuno-reactive peptides, two also possess significant hyperglycemic activity.