Steroids classes

Steroid Antibiotics. The steroid antibiotics are a stmcturaHy diverse class of steroids that have a common biological function, ie, antibacterial, antifungal, antiviral, or antitumor activities. This group of compounds can overlap with other steroid classes Hsted above. Eusidic acid [6990-06-3] (67), helvohc acid [29400-42-8] (68), and cephalosporin [13258-72-5] (69) exemplify a set of antibacterial steroids that contain a prolanostane skeleton with an... 

True profile analysis requires scanning over the whole mass range for the acquisition of all data on excreted compounds. Quantitation has been more challenging on a quadrupole instrument because total ion current peaks are seldom a single component and extracted-ion chromatograms (EICs) when recovered from scanned data are of poor quality due to the lower sensitivity of scanning GC-MS. Thus, we developed profile analysis based on SIM of selected analytes but tried to ensure the components of every steroid class of interest were included. For ion traps the fundamental form of data collection (in non-MS/MS mode must be full -scans). Thus, the quantitative data produced are EICs obtained from scanned data. The EICs are of the same ions used for SIM in quadrupole instruments and the calibration external standards are the same. 

Hormones detected in milk include some from the peptide and steroid classes but none of the amino hormones. Prolactin, a protein of 199 amino acid residues, is normally present in a concentration of about 50 /tg/liter, and the hexapeptide gonadotropin-releasing hormone of the hypothalmus at about 1.5 g/liter. Steroid hormones from the adrenal cortex include the glucocorticoids cortisol and corticosterone, totaling 0.2-0.6 /tg/liter. Those from the ovary—progesterone, estrone, and estradiol—have concentrations of 10-30, 30, and 175 /ig/liter, respectively. Hormones in milk have been reviewed by Koldovsky (1980) and Pope and Swinburne (1980). The prolactin in milk is biologically active (Gala et al. 1980). 

One important synthesis of the steroid class of compounds (about which more later) requires a Grignard reagent with this structure ... 

Synonyms Male sex hormones Chemical/Pharmaceutical/Other Ceass Androgens are natural and synthetic congeners of the steroid class of compounds Chemical Structure ... 

Norethindrone 31a, the gestagenic component in the combination pill, is smoothly accessible from estrone-methylether by partial synthesis [71]. The reaction sequence begins with a dearomatization (Birch reduction) and ends with an ethynylation (Scheme 1-10), necessary for the oral applicability. Technical production of estrone 24 (or estradiol) from inexpensive steroids such as diosgenin or cholesterol by partial synthesis is also feasible. Pyrolytic aromatization (Inhoffen at Schering AG) assists the transition from the steroid to the 19-nor-steroid class (such as from androsta-1,4-dien-l 7/i-ol-3-one 32 to estradiol 33 [72]). 

However, the sex-hormones belong to the steroid class of compoimds and are produced in the gonads, i.e., testes in the male and ovaries in the female. In fact, their activity seems to be controlled and monitored by the hormones that are produeed in the anterior lobe of the pituitary glands. Perhaps beeause of this inherent characteristies the sex hormones are invariably termed as the secondary sex hormones and the hormones of the anterior lobe of the pituitary are called the primary sex-hormones. 

Because we know nothing about the potential pheromonal functions of the detected steroid classes (El, E2—3g, Etio) which induce ventilatory responses in Neogobius, the biological significance of the similar discriminatory abilities demonstrated by EOG and behavioural cross-adaptation is not clear. In particular, it is not known whether these be-haviourally active steroids are sex pheromones and, if they are, whether they function as a pheromonal mixture, or whether each steroid class functions as a distinct pheromone. It is also not known what role the ventilation rate response plays in pheromonal function. If the ventilation response serves only as a means to prolong exposure to a putative pheromone, novel individual compounds may evoke a ventilation increase, but a combination of steroidal odours may be necessary to activate a reproductive behaviour or physiological process. However, if encoding of the components of a steroid mixture occurs in and... 

Even when adopting a targeted approach, the coverage of lipids in a specific class can still be restricted by the dominance of a few very abundant lipids. This may be the case for steroid analysis where cholesterol is often the most abundant steroid by two orders of magnitude. This problem can be minimized by subdivision of the steroid class according to hydropho-bicity where cholesterol and more hydrophobic steroids represent one class, and oxysterols (oxidized forms of cholesterol and its precursors) and less hydrophobic metabolites represent a second class [45]. This is an approach we adopted for the analysis of steroid sulphates and bile acid/ alcohol conjugates by shotgun steroidomics, and in our LC-ESl-MS/MS work on oxysterols and cholestenoic acids in brain [46,47], plasma [48], and cerebrospinal fluid (CSF) [49]. 

In the steroid class, an angulated saturated steroid with carbonyl groups is highly active. Terpenes with saturated rings containing a carbonyl group are also active. 

The steroid class of compounds was studied intensively for the relation of structure to inducing function because, of all the inducing compounds known, only the steroids are derived from physiological sources [65,66]. In addition, certain clinical observations, reviewed by DeMatteis [2], suggested that during puberty, pregnancy, and menstruation—that is, when steroid production changed markedly—the symptoms of hepatic porphyria in patients with this disease were exacerbated or diminished. 

Topical steroids (class I steroid bid to affected area for... 

The reader may have noticed in the general structures for the steroid classes that a 5a often precedes the steroid name. In many classes of natural products,... 

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