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Development and validation of an HPTLC method for estimation of coronarin D in Hedychium coronarium rhizome

Ray A., Dash B., Sahoo S., Sahoo A., Jena S., Kar B., Chatterjee T., Ghosh B., Nayak S.

Acta Chromatographica

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2017

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Vol. 29, no. 3

415--426

EN

Rhizome extracts of Hedychium coronarium are widely used as phytotherapeutics. As of date, there is no documented study on the standardization of H. coronarium extract, and the following research is an effort in this direction. Coronarin D is an important bioactive compound present in H. coronarium which shows chemopreventive activity against cancer. H. coronarium extracts were assessed for coronarin D content for the first time. The extraction was checked using different solvents: n-hexane, acetone, and methanol. Coronarin D was separated on silica gel 60F254 high-performance thin-layer chromatography (HPTLC) plates by isocratic gradient method using n-hexane-ethyl acetate (80:20 v/v) as mobile phase. Densitometric quantification was performed at 231 nm in absorption mode. This method gave a well-defined peak at Rf 0.20 corresponding to coronarin D. The method was validated using International Conference on Harmonization (ICH) guidelines in terms of precision, repeatability, and accuracy. Linearity range of coronarin D was 200–1000 ng spot−1 with a correlation coefficient of R2 ± SD = 0.9987 ± 2.62% in the concentration range of 200–1000 ng spot−1. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 35 and 115 ng, respectively. Accuracy of the method was checked by recovery studies conducted at three different concentration levels, and the average percentage recovery was found to be 98.22 % for coronarin D. Among the different solvents, acetone produced maximum extraction efficiency of coronarin D. The proposed HPTLC method can be applied for robust identification and quantitative determination of coronarin D in H. coronarium extracts.

2

A complex measure for linear grammars

Chattopadhyay I., Ray A.

Demonstratio Mathematica

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2005

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Vol. 38, nr 3

761--775

EN

The signed real measure of regular languages, introduced and validated in recent literature, has been the driving force for quantitative analysis and synthesis of discrete-event supervisory (DES) control systems dealing with finite state automata (equivalently, regular languages). However, this approach relies on memoryless state-based tools for supervisory control synthesis and may become inadequate if the transitions in the plant dynamics cannot be captured by finitely many states. From this perspective, the measure of regular languages needs to be extended to that of non-regular languages, such as Petri nets or other higher level languages in the Chomsky hierarchy. Measures for non-regular languages has not apparently been reported in open literature and is an open area of research. As a step toward achieving this goal, this paper introduces a complex measure of linear context free grammars (LCFG) that belong to the class of non-regular languages. The proposed complex measure becomes equivalent to the signed real measure, reported in recent literature, if the LCFG is degenerated to a regular grammar.

3

Optimal supervisory control of regular languages

Ray A., Fu J., Lagoa C.

Demonstratio Mathematica

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2004

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Vol. 37, nr 4

991--1013

EN

This paper presents an algorithm for optimal control of regular languages, realized as deterministic finite state automata (DFSA), with (possible) penalty on event disabling. A signed real measure quantifies the behavior of controlled sublanguages based on a state transition cost matrix and a characteristic vector as reported in an earlier publication. The performance index for the proposed optimal policy is obtained by combining the measure of the supervised plant language with the cost of disabled controllable event(s). Synthesis of this optimal control policy requires at most n iterations, where n is the number of states of the DFSA model generated from the unsupervised regular language. The computational complexity of the optimal control synthesis is polynomial in n. The control algorithms are illustrated with an application example of a twin-engine surveillance aircraft.

4

Measure of regular languages

Surana A., Ray A.

Demonstratio Mathematica

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2004

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Vol. 37, nr 2

485--503

EN

This paper reviews and extends the recent work on signed real measure of regular languages within a unified framework. The language measure provides total ordering of partially ordered sets of sublanguages of a regular language to allow quantitative evaluation of the controlled behavior of deterministic finite state automata under different supervisors. The paper presents a procedure by which performance of different supervisors can be evaluated based on a common quantitative tool. Two algorithms are provided for computation of the language measure and their equivalence is established along with a physical interpretation from the probabilistic perspective.