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Chromatographic identification of two biologically important triterpenoids from the chloroform extract of Rhizophora mucronata

Hridya V. K, Godson P. S, Chandrasekar N.

Acta Chromatographica

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2012

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Vol. 24, no. 1

123--129

EN

Mangroves are the source of several bioactive secondary metabolites and have proven activity against human, animal and plant pathogens. Rhizophora mucronata is a mangrove species belonging to the family Rhizophoraceae. Betulin and lupeol are two naturally occurring pentacyclic triterpenoids having excellent biological properties. Chloroform extract of R. mucronata, collected from Pitchavaram, Muthupett and Manakudy regions of Tamilnadu, was chromatographed on silica gel 60F254 plates with nhexane and ethyl acetate (80:20) (v/v) as the mobile phase. Derivatizations were done using anisaldehyde and sulfuric acid reagents. The triterpenoids such as betulin and lupeol were identified through HPTLC method. This is the first report for the thin layer chromatographic (TLC) identification of triterpenoids such as betulin and lupeol from R. mucronata, which will be the most valuable information to identify the antimalarial and antiviral activities.

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Appraisal of tsunami inundation and run-up along the coast of Kanyakumari District, India - GIS analysis

Chandrasekar N., Immanuel J.L., Sahayam J.D., Rajamanickam M., Saravanan S.

Oceanologia

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2007

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No. 49 (3)

397-412

EN

On 26 December 2004, a tsunami severely affected almost all the coastal villages of Kanyakumari District, India. It was one of the worst affected coastal sectors of South India. An attempt has been made here to assess the impact of the tsunami hazard on coastal landforms and the level of inundation using GIS techniques. The areas of inundation were surveyed and mapped by fixing regular transects along the coastal regions. The percentage of inundated area in the total area was estimated. It was found that inundation was higher on low-lying coasts and relatively less on elevated coasts. In some cases, the extent of inundation was a few kilometres in relation to other coasts, but the percentage of inundated area in the total coastal area was high. The extent of inundation along the study area varied from 50 m to 450 m. Inundation was minimal in coastal villages like Kanyakumari, Agastheeswaram, Madhysoodhanapuram and Dharmapuram, but extensive at Colachel. The percentage of inundated area in the total area ranges from 8% (Dharmapuram) to 39% (Colachel). The degree of inundation was controlled by coastal geomorphological features such as sand dunes, cliffs, coastal vegetation, nature and configuration of the beach, not to mention the angle and velocity of the invading tsunami surge.

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Light minerals of beach sediments from Southern Tamilnadu, south east coast of India

Cherian A., Chandrasekar N., Rajamanickam V.

Oceanologia

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2004

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No. 46 (2)

233-252

EN

A brief investigation of light minerals along the beaches between Valinokkam and Tuticorin has been carried out for the first time along the Southern Tamilnadu coast in order to discover the provenance of the sediments. The study spotlights a wide variation in light mineralogy along the three zones of the investigated area (Valinokkam, Vaippar and Tuticorin). A higher percentage of quartz is reported from the Valinokkam (48.34 to 68.63%) and Tuticorin zones (55.66 to 73.05%) than from the Vaippar zone (40.24 to 60.77%). The trend with regard to the maturity index is similar, with appreciably higher values in Valinokkam (1.15 to 1.89) and Tuticorin (1.61 to 1.94) than Vaippar (0.79 to 1.39). Morphological analysis of quartz grains shows a higher order of sphericity and roundness values in Valinokkam and Tuticorin as compared to Vaippar. Moreover, the surface texture of quartz grains observed with the aid of scanning electron microscope (SEM) photographs reveals the presence of different depositional environments and the multiple origin of beach sediments in the study area. From the present study of the light mineralogy of beach sediments, it is inferred that the source of the sediments is a mixed type: igneous and metamorphic crystalline rocks, together with palaeosediments.