plants Article Three Novel Biphenanthrene Derivatives and a New Phenylpropanoid Ester from Aerides multiflora and Their a-Glucosidase Inhibitory Activity May Thazin Thant 1,2, Boonchoo Sritularak 1,3,* , Nutputsorn Chatsumpun 4, Wanwimon Mekboonsonglarp 5, Yanyong Punpreuk 6 and Kittisak Likhitwitayawuid 1 1 Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand;
[email protected] (M.T.T.);
[email protected] (K.L.) 2 Department of Pharmacognosy, University of Pharmacy, Yangon 11031, Myanmar 3 Natural Products for Ageing and Chronic Diseases Research Unit, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand 4 Department of Pharmacognosy, Faculty of Pharmacy, Mahidol University, Bangkok 10400, Thailand;
[email protected] 5 Scientific and Technological Research Equipment Centre, Chulalongkorn University, Bangkok 10330, Thailand;
[email protected] 6 Department of Agriculture, Kasetsart University, Bangkok 10900, Thailand;
[email protected] * Correspondence:
[email protected]; Tel.: +66-2218-8356 Abstract: A phytochemical investigation on the whole plants of Aerides multiflora revealed the presence of three new biphenanthrene derivatives named aerimultins A–C (1–3) and a new natural Citation: Thant, M.T.; Sritularak, B.; phenylpropanoid ester dihydrosinapyl dihydroferulate (4), together with six known compounds Chatsumpun, N.; Mekboonsonglarp, (5–10). The structures of the new compounds were elucidated by analysis of their spectroscopic W.; Punpreuk, Y.; Likhitwitayawuid, data. All of the isolates were evaluated for their a-glucosidase inhibitory activity. Aerimultin C K. Three Novel Biphenanthrene (3) showed the most potent activity. The other compounds, except for compound 4, also exhibited Derivatives and a New stronger activity than the positive control acarbose.