Development of micro total analysis system for detection of water pathogens

Master'sMASTER OF ENGINEERIN

Pentacyclic and hexacyclic cucurbitacins from Elaeocarpus petiolatus

Four undescribed cucurbitacins, designated as petiolaticins A–D, and four known cucurbitacins were isolated from the bark and leaves of Elaeocarpus petiolatus (Jack) Wall. Their chemical structures were elucidated based on detailed analyses of the NMR and MS data. The absolute configuration of petiolaticin A was also determined by X-ray diffraction analysis. Petiolaticin A represents a cucurbitacin derivative incorporating a 3,4-epoxyfuranyl-bearing side chain, while petiolaticin B possesses a furopyranyl unit fused to the tetracyclic cucurbitane core structure. Petiolaticins A, B, and D were evaluated in vitro against a panel of human breast, pancreatic, and colorectal cancer cell lines. Petiolaticin A exhibited the greatest cytotoxicity against the MDA-MB-468, MDA-MB-231, MCF-7, and SW48 cell lines (IC50 7.4, 9.2, 9.3, and 4.6 μM, respectively). Additionally, petiolaticin D, 16α,23α-epoxy-3β,20β-dihydroxy-10αH,23βH-cucurbit-5,24-dien-11-one, and 16α,23α-epoxy-3β,20β-dihydroxy-10αH,23βH-cucurbit-5,24-dien-11-one 3-O-β-D-glucopyranoside were tested for their ability to inhibit cell entry of a pseudotyped virus bearing the hemagglutinin envelope protein of a highly pathogenic avian influenza virus. Petiolaticin D showed the highest inhibition (44.3%), followed by 16α,23α-epoxy-3β,20β-dihydroxy-10αH,23βH-cucurbit-5,24-dien-11-one (21.0%), and 16α,23α-epoxy-3β,20β-dihydroxy-10αH,23βH-cucurbit-5,24-dien-11-one 3-O-β-D-glucopyranoside showed limited inhibition (9.0%). These preliminary biological assays have demonstrated that petiolaticins A and D possess anticancer and antiviral properties, respectively, which warrant for further investigations

A Bis-benzopyrroloisoquinoline Alkaloid Incorporating a Cyclobutane Core and a Chlorophenanthroindolizidine Alkaloid with Cytotoxic Activity from <i>Ficus fistulosa</i> var. <i>tengerensis</i>

Tengerensine (<b>1</b>), isolated as a racemate and constituted from a pair of bis-benzopyrroloisoquinoline enantiomers, and tengechlorenine (<b>2</b>), purified as a scalemic mixture and constituted from a pair of chlorinated phenanthroindolizidine enantiomers, were isolated from the leaves of <i>Ficus fistulosa</i> var. <i>tengerensis</i>, along with three other known alkaloids. The structures of <b>1</b> and <b>2</b> were determined by spectroscopic data interpretation and X-ray diffraction analysis. The enantiomers of <b>1</b> were separated by chiral-phase HPLC, and the absolute configurations of (+)-<b>1</b> and (−)-<b>1</b> were established via experimental and calculated ECD data. Compound <b>1</b> is notable in being a rare unsymmetrical cyclobutane adduct and is the first example of a dimeric benzopyrroloisoquinoline alkaloid, while compound <b>2</b> represents the first naturally occurring halogenated phenanthroindolizidine alkaloid. Compound (+)-<b>1</b> displayed a selective in vitro cytotoxic effect against MDA-MB-468 cells (IC₅₀ 7.4 μM), while compound <b>2</b> showed pronounced in vitro cytotoxic activity against all three breast cancer cell lines tested (MDA-MB-468, MDA-MB-231, and MCF7; IC₅₀ values of 0.038–0.91 μM)