Phloroglucinol Derivatives with Unusual Skeletons from Cleistocalyx operculatus and Their in Vitro Antiviral Activity

Abstract

Four novel phloroglucinol derivatives (1-4) featuring a 2,4-dimethyl-cinnamyl-phloroglucinol moiety, along with their putative biosynthetic precursors 5 and 6, were isolated from the leaves of Cleistocalyx operculatus. Compounds 1 and 2 are two pairs of new enantiomeric phloroglucinol dimers possessing an unprecedented polycyclic skeleton with a highly functionalized dihydropyrano[3,2- d]xanthene tetracyclic core. Compounds 3 and 4 are two new phloroglucinol-terpene adducts (PTAs) with a novel carbon skeleton. The structures of 1-4 including their absolute configurations were unambiguously accomplished by combination of extensive spectroscopic analyses, X-ray crystallography, and quantum chemical ECD calculations. A hypothetical biosynthetic pathway for 1-4 was also proposed. Compound 1 exhibited a promising in vitro antiherpes simplex virus type-1 (HSV-1) effect.

Antimicrobial Chlorinated Carbazole Alkaloids from the Sponge‐Associated Actinomycete Streptomyces diacarniLHW51701

“…In the structure refinements, nonhydrogen atoms were refined anisotropically, and the hydrogen atom positions were geometrically idealized and allowed to ride on their parent atoms. [ 20 ] The crystallographic data of 1 and 4 have been deposited in Cambridge Crystallographic Data Center (CCDC 2050017 and 2050018, respectively). The data can be obtained freely from Cambridge Crystallographic Data Centre, 12, Union Road, Cambridge CB2 1EZ, UK (fax (+44) 1223 336 033; e‐mail: data_request@ccdc.cam.ac.…”

New Indole Diketopiperazine Alkaloids from Soft Coral‐Associated Epiphytic Fungus Aspergillus sp. EGF 15‐0‐3

“…The quantum chemical ECD calculations of 3 was performed according to the reported procedures . Briefly, 78 conformers were obtained under MMFF94s molecular force field by using SYBYL X 2.1.1 program and were subsequent subjected to Gaussion09 software for quantum chemical structural optimization and ECD calculations.…”

Structures and Bioactive Properties of Myrtucommulones and Related Acylphloroglucinols from Myrtaceae

“…The available literature concerning Myrtaceae also reports the existence of products that are not classifiable as acylphloroglucinol oligomers, and are hence not included in this review. Particularly, monomers of either acylphloroglucinol (e.g., callisalignene A–C [25], xanchryone A–D [55], operculatol A–B [56]) or syncarpic acid (e.g., myrtucommulone K [35,57], callistiviminene A–O [58]), and flavonoids conjugated to a syncarpic acid residue (e.g., kunzeanones A–C [59], myrtocummunines A–D [51]).…”