Total synthesis of orellinine,a minor toxic component of the fungusCortinarius orellanus fries

Summary The 3,3,4,4-tetrahydroxy-2,2-bipyridyl-N-oxide has been synthesized by dealkylation of the corresponding tetramethyl derivative. The chemical properties of this compound are identical to those reported for the minor fungal toxin ofCortinarius orellanus, orellinine.This work is part of the Tesi di Laurea of Miss Cinzia Pierucci.     

Occurrence of 3-epi-22-deoxy-20-hydroxyecdysone and its phosphoric ester in diapause eggs of the silkworm,Bombyx mori

Ecdysteroids in diapause eggs of the silkworm,Bombyx mori, were analyzed using high-performance liquid chromatography (HPLC) combined with radioimmunoassay (RIA). A relatively large amount of an unidentified free ecdysteroid and its phosphoric ester (conjugated form) were detected. These two compounds were isolated by a combination of column chromatography on silicic acid, thin-layer chromatography (TLC), and HPLC using a reverse-phase (RP) column. The purified compounds were identified as 3-epi-22-deoxy-20-hydroxyecdysone (22d20E) and 3-epi-22-deoxy-20-hydroxyecdysone 2-phosphate (22d20E2P) by means of mass spectrometry and nuclear magnetic resonance spectroscopy. to our knowledge, this is the first report of 22d20E and 22d20E2P.     

Microbiological assay of cyclic 3′, 5′-AMP

Zusammenfassung Es wird ein mikrobiologisches Testverfahren beschrieben, mit dem sehr geringe Mengen von zyklischem Adenosin 3, 5-monophosphat quantitativ nachgewiesen werden können.     

N,N′-di(piperidino-methyl)-3,3′-diindolyl-methane (DIM), a diindolylmethane derivative of neuroplegic action

Zusammenfassung Ein neues Diindolyl-methan-derivat, das N, N-di(piperidino-methyl)-3, 3-diindolyl-methan, wurde synthetisiert; es verursacht im Tierversuch schon in Dosen von 3–5 mg/kg einen langanhaltenden zentralen Depressoreffekt.     

Über das Vorkommen verschieden substituierter Chalkone während der Mikrosporogenese beiTulipa

Summary During the development of anthers inTulipa cv. Apeldoorn the following chalcones were isolated: 2, 3, 4, 4, 6-pentahydroxychalcone as the main component and 2, 4, 4, 6-tetrahydroxy-3-methoxychalcone as well as 2, 4, 4, 6-tetrahydroxychalcone in a very small amount.

---

---

Die Untersuchungen wurden mit Mitteln der Deutschen Forschungsgemeinschaft unterstützt.     

A new synthetic method of coumestan derivatives

Zusammenfassung Die Synthese von 7-Hydroxy-5,6-dimethoxybenzofurano[3,2:3,4]coumarin aus 7,2-Dihydroxy-oder 7-Benzyloxy-2-hydroxy-4,5-dimethoxyisoflavon wird beschrieben.     

Microbiological transformation of biflavone

Summary Incubation of 5,5-7,7-tetramethoxy-8,8-biflavone withAspergillus niger results in the formation of 4,4-dihydroxy-5,5-7,7-tetramethoxy-8,8-biflavan.Part of this work was done at Allahabad University, Chemical Laboratories.     

Polyhydroxylated metabolites oftrans-stilbene in the rat

Zusammenfassung Nach Eingabe vontrans-Stilben bei Ratten wurden die grössten Mengen im Harn als 3,4,4-Trihydroxystilben, 3,4,4-Trihydroxybibenzyl und 3,3, 4,4-Tetrahydroxybibenzyl nachgewiesen. Die Bibenzylderivate werden nachscheinlich nach Ausscheidung in der Galle von Darmbakterien metabolisiert.     

Effect of urochordamines on larval metamorphosis of ascidians

Two pteridine-containing bromophysostigmine alkaloids, urochordamine A and B, which were isolated from ascidians as larval metamorphosis promoters, were converted to more polar compounds, urochordamine A and B, respectively, when left standing in protic solvents. These four compounds promoted larval metamorphosis of the ascidianHalocynthia roretzi in the order A>A>B>B, and induced metamorphosis of the pediveliger larvae of the musselMytilus edulis galloprovincialis.     

The selective esterification of the 5′-hydroxyl of thymidine

Zusammenfassung Ein einfacher Weg zur selektiven Esterbildung mit der 5-Hydroxylgruppe von Thymidin wird beschrieben. Beispiele: Thymidin-5-phosphat, Thymidin-5-sulfat und Thymidin-5-trichloracetat.     

The syntheses of axillarin and its related compounds

Zusammenfassung Axillarin (5, 7, 3, 4-Tetrahydroxy-3,6-dimethoxyflavon). 5,3,4-Trihydroxy-3,6,7-trimethoxyflavon und 5,7,3,4-Tetrahydroxy-3,8-dimethoxyflavon wurden synthetisiert.     

A new synthesis of dehydromunduserone

Zusammenfassung Eine einfache Synthese von Dehydromunduseron aus 7,2,4,5-Tetramethoxy-isoflavon wird beschrieben.     

Hotspots of homologous recombination

Homologous recombination occurs at higher than average frequency at and near hotspots. Hotspots are special nucleotide sequences recognized by proteins that promote, directly or indirectly, a rate limiting step of recombination. This review focuses on two well-studied examples, the Chi sites of the bacteriumEscherichia coli and the M26 site of the fission yeastSchizosaccharomyces pombe. Chi, 5 G-C-T-G-G-T-G-G 3, is recognized by the RecBCD enzyme, which nicks the DNA near Chi and produces a 3-ended single-stranded DNA tail; this tail is a potent substrate for homologous pairing by RecA and single-stranded DNA binding proteins. M26, 5 A-T-G-A-C-G-T 3, is recognized by a heterodimeric protein and stimulates, by an as-yet-unknown mechanism, meiotic recombination at and near theade6 gene. Additional hotspots in bacteria, fungi, and mammals enhance recombination directly or indirectly via a variety of mechanisms. Although hotspots are widespread among organisms, the biological role of their localized enhancement of recombination remains a matter of speculation.     

Chromosomes and giemsa-bands of the Idaho spotted ground squirrel,Spermophilus brunneus (Howell)

-Spermophilus brunneus . , 13 18 ,S. brunneus S. townsendii mollis (2n=38) , , ; ;S. brunneus . S. brunneus , Spermophilus.

---

---

Supported by National Science Foundation Grants No. GB32114X and No. GB 29131X, and the Sprague Foundation. We thankD. Pozin for technical assistance.     

Synthesis of 5′-deoxypyridoxal derivatives

Summary A convenient synthesis of 5-deoxypyridoxal derivatives is described. The method involves catalytic hydrogenolysis of the corresponding 5-phosphorylated derivatives; products are obtained in high yields.Supported by PHS Grant No. 5429-16-9.     

Effect of dipyridamole on glomerular mesangial cell ecto-5′-nucleotidase expression

Although dipyridamole has been extensively studied as an anti-aggregating agent, its mechanism of action has not been elucidated. Cultured mesangial cells were treated with dipyridamole 1–100 M from 6–72 h. Ecto-5-nucleotidase activity approximately doubled (from 115±11 to 226±14 nmol/min/mg) after treatment with 100 M dipyridamole for 72 h. This effect was concentration- and time-dependent. Cycloheximide, an inhibitor of protein synthesis, did not alter basal 5-nucleotidase activity. However, it prevented stimulation by 5 M dipyridamole. Adenosine availability at the receptor sites was increased by dipyridamole and S-(p-nitrobenzyl)-6-thioinosine (NBTI), which inhibit adenosine uptake into the cell. Addition of dipyridamole or NBTI to the adenosine-treated mesagial cells produced an additive increase in ecto-5-nucleotidase activity. Dipyridamole, through its effect on extracellular adenosine and ecto-5-nucleotidase, may have an influence upon regulation of the glomerular microcirculation.     

Enhancement of anaphylaxis of isolated smooth muscle by adenosine phosphates and inhibition of anaphylactic mechanisms by adenosine-3′,5′-cyclic monophosphate

Zusammenfassung Zyklisches 3,5-Adenosinmonophosphat hindert in vitro die Anaphylaxis des glatten Muskels vom Meerschweinchenuterus, während Adenosin und Adenosin-5-Monophosphat die anaphylaktische Reaktion erhöhen.     

The oxidation of N-2-Fluorenamine and 4-Aminobiphenyl by peracetic acid

Zusammenfassung Im Gegensatz zu neueren Befunden von anderen Autoren finden wir, dass die Oxydation von 2-Fluorenamin oder 4-Aminodiphenyl mit Peressigsäure keine Nitrosoderivate bildet, sondern die Azoverbindungen 2,2-Azoxybisfluoren und 4,4-Azobisdiphenyl.p-Nitroanilin wird zu einem Gemisch oxydiert, aus dem manp, p-Dinitroazoxybenzol undp, p-Dinitroazobenzol durch Chromatographie an Kieselgel isolieren kann.

---

---

Supported by a grant (C-2571) from the National Cancer Institute, U.S. Public Health Service.     

Induction of ingestive responses by cAMP applied into the rat hypothalamus

Riassunto L'applicazione stereotassica di microdosi di dibutirril-adenosin-3 5 monofosfato nell'area ipotalamica laterale zona incerta di ratti sazi causa un netto aumento nell'ingestione di acqua. L'aumento è molto simile a quello causato dalla carbamoilcolina posta nella stessa zona.