A [2 + 2] Cycloaddition Dimer and a Diels–Alder Adduct fromAlpinia katsumadai

Abstract

An unusual katsumadain dimer via a [2 + 2] cycloaddition, katsumadain C (1), and a unique chalcone-diarylheptanoid adduct via a Diels-Alder reaction, calyxin Y (2) with novel carbon frameworks, were isolated from the seeds of Alpinia katsumadai. Their structures and relative configurations were determined by spectroscopic evidence.

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“…Chemical Constituents: Majority of the chemical compounds isolated from genus Alpinia has been shown multiple medical potentials and possess novel chemical structures 58,59 Other than above chemical constituents some glycosides 75 , lignins 76 , phenylpropanoids and volatile oils 77 were found in the genus Alpinia. A new katsumadain dimer named "katsumadain" has been isolated from Alpinia katsumadai 78 . A plant growth inhibitor named dihydro-5, 6dehydrokawain has been isolated from Alpinia speciosa leaves 79 .…”

Flavonoids: Classification, Biosynthesis and Chemical Ecology

“…Several species reported the presence of chalcone dimers bound by a cyclobutane (Figure 2) [29][30][31][32][33][34][35]. The phytochemical study of the roots of Dahlstedtia grandilora was observed, and for the irst time, the occurrence of dimerization in retrochalcones was noted [24].…”

“…The phytochemical study of the roots of Dahlstedtia grandilora was observed, and for the irst time, the occurrence of dimerization in retrochalcones was noted [24]. The mechanisms of [2 + 2] cycloaddition involved in the formation of these compounds are suggested [30,35]. In spite of the lack of biosynthetic studies of these natural products, much efort has been made in elucidating the biosynthetic pathways of lavonoids from a genetic perspective.…”

Bioinspired total synthesis of katsumadain A by organocatalytic enantioselective 1,4-conjugate addition

“…We recently reported the biomimetic total synthesis of katsumadain C [7], a natural product isolated from the same resource as katsumadain A and B [8]. As part of our continuous interest in the synthesis of bioactive 2-pyranone-derived natural products, we launched a project aiming to develop a highly efficient route for the synthesis of katasumadain A as well as its analogues, which would pave the way for their application in further biomedical investigations.…”