On extremal properties for the polar derivative of polynomials

If p(z) is a polynomial of degree n having all its zeros on |z| = k, k ≤ 1, then it is proved[5] that max |z|=1 |p′(z)| ≤ kn1n + kn m|z|=ax1 |p(z)|. In this paper, we generalize the above inequality by extending it to the polar derivative of a polynomial of the type p(z) = cnzn + ∑n j=μ cn jzn j, 1 ≤μ≤ n. We also obtain certain new inequalities concerning the maximum modulus of a polynomial with restricted zeros.     

Biosynthesis of thalicarpine

The incorporation of (±)-, norlaudanosoline, ?nor-reticuline, ?N-methylcoclaurine and ?norlaudanidine into thalicarpine in Cocculus laurifolius DC has been studied and specific utilization of (±)- reticuline is demonstrated. The evidence supports that both the “halves” of thalicapine are derived from reticuline. Parallel feedings of (S)-, and (R)-, reticulines showed that the stereospecifity is maintained in the biosynthesis of thalicarpine from the 1-benzyl-tetrahydroisoquinoline precursor.A double-labelling experiment with (±)-[1-³H, 4′-O¹⁴CH₃] nor-reticuline has shown that the 4′OMe group of a nor-reticuline unit is lost in the biotransformation into thalicarpine. Feeding experiments also revealed that the plants can convert (S)-bolding and (S)-isoboldine into thalicarpine.     

EFFECT OF PHOTIC STIMULATION ON THE HUMAN MENSTRUAL CYCLE

To test the hypothesis that artificial light can be used to regularize the human menstrual cycle, 16 women with histories of menstrual irregularity and/or abnormally long cycles were studied. It was assumed that a 29-day cycle is the "normal" length. Thus, light exposure was begun on the evening of day 14, with the expectation that ovulation would be triggered by day 15 and menstruation on day 30. The light regimen was continued for 2-3 nights more. Temperature graphs indicated all subjects were ovulating. 41 control and 41 matching experimental cycle lengths were obtained. The experimental cycle lengths were less variable than the control lengths and showed a sharp peak at 29 days. In the 11 subjects exposed to light for more than 1 cycle, 9 showed a decrease in the range of cycle length (3.3% level of significance difference between control and experimental groups in terms of cycle length). It is concluded that these data provide evidence that photic stimulation can regularize menstrual cycle length and thus influence the time of ovulation, thereby facilitating use of the rhythm method of birth control. Further studies involving larger samples and more sophisticated measurements of ovulation in relation to photic stimulation are recommended.     

Correlation between topological features and surface tension of binary liquid mixtures

Summary The excess surface tension of a large number of binary liquid mixtures has been correlated with their topological features quantified in terms of the molecular connectivity indices. The agreement between the calculated and experimental ^E values is reasonably well for all the mixtures. A simple correlation has also been proposed between ^E and molar excess volume (V ^E ) of a binary mixture. The correlation is quite useful in correlating ^E data even for the mixtures where either one or both the components are associated in the pure state and/or there is interaction between them.

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Korrelation zwischen topologischen Gegebenheiten und Oberflächenspannung von binären flüssigen Mischungen

Zusammenfassung Die Exzeß-Oberflächenspannungen einer großen Anzahl von binären flüssigen Mischungen wurden mit der Topologie ihrer Komponenten in Form der molekularen Konnektivitätsindices korreliert. Die Übereinstimmung zwischen den ^E -Werten ist für alle Mischungen relativ gut. Es wurde ebenfalls eine einfache Korrelation zwischen ^E und den molaren Exzeß-Volumina (V ^E ) der binären Mischungen vorgeschlagen. Diese Korrelierung ist nützlich, um die ^E -Werte sogar dann für die Korrelation von Mischungen verwenden zu können, wenn entweder eine oder beide Komponenten im Reinzustand assoziiert sind und/oder eine Wechselwirkung zwischen ihnen besteht.

     

Late stages in the biosynthesis of abnormal erythrina alkaloids

The incorporation of (±)-, N-norprotosinomenine, N-nor-orientaline, N-nor-reticuline, norlaudanosoline, protosinomenine, and N-[2-(3-hydroxy-4-methoxyphenyl)ethyl]-2-(4-hydroxyphenyl) ethylamine into coccuvine has been studied, and the specific utilisation of the (±)-norprotosinomenine demonstrated. A double labelling experiment with (±)-[1-³H,4'-methoxy-¹⁴C]-N-norprotosinomenine showed that the 4'-O-Me group of the precursor is retained in the bioconversion and the erythrinan ring system is not formed by addition of secondary amino function onto an ortho-quinone system. Feeding of (±)-[1-³H, 7-methoxy-¹⁴C]norprotosinomenine established that O-demethylation is the terminal step in the biosynthesis of coccuvine. Feeding of labelled abnormal Erythrina alkaloids revealed that isococculidine is converted into coccoline via coccuvinine and isococculine into coccolinine via coccuvine.     

Biosynthesis of magnoflorine and laurifoline

The incorporation of (±)-, nor-laudanosoline, nor-protosinomenine, nor-orientaline, norreticuline and reticuline and reticuline methiodide into magnoflorine and laurifoline has been studied and specific incorporation of nor-reticuline and reticuline demonstrated. Parallel feeding experiments with (+)-S and (?)-(R)-reticulines demonstrated specific incorporation of (+)-(S)-isomer into these bases.     

Biosynthesis of tylophorine and tylophorinine

Administration of 3,4-dihydroxyphenyl[2-¹⁴C] alanine to young Tylophora asthmatica plants revealed that ring B and carbon atoms C₉ and C₇ of tylophorine and tylophorinine are derived from dopa. Tracer experiments with 6,7-diphenylhexahydroindolizines (1–7) and (26) demonstrated that compound 1 is efficiently and specifically incorporated into tylophorine (13) and tylophorinine (16). Compounds (3), (4) and (26) were not metabolized by the plants to form (13) and (16) whereas (5) and (6) were utilized to yield (13) and (16). Compound (2) was very poorly converted into (13) and (16) and thus is not on the major biosynthetic pathway of (13) and (16).     

A simple and efficient tetradentate Schiff base derived palladium complex for Suzuki–Miyaura reaction in water

A simple and efficient catalytic system based on Pd complex of tetradentate Schiff base ligands is found to be highly active (up to 99% isolated yield) for Suzuki–Miyaura reaction of aryl bromides with arylboronic acids in water at room temperature. Further the scope of this protocol has been extended to the Suzuki–Miyaura cross-coupling reaction of aryl chlorides with arylbronic acids in isopropanol.