Four new cinnamoyl-phloroglucinols from the leaves of Xanthostemon chrysanthus

Chiral Isolation and Absolute Configuration of (+)‐ and (−)‐Xanchryones F and G from Xanthostemon chrysanthus

“…A comparison of the NMR data of (+)-1a with those of the known compound champanone A [10] suggested the presence of a cinnamoyltriketone unit (part A, Figure 3). This observation was further supported by the HMBCs between HÀ C(16) and C(1)/C(2)/C(3), between HÀ C(17)/HÀ C(18) and C(3)/C(4)/C(5), between OHÀ C(5) and C(5)/C(6)/C(7)/C (8), between HÀ C(8) and C (10) and between HÀ C(9) and C(7)/C(11), as well as the 1 H, 1 H-COSY spin systems of HÀ C(11) to HÀ C (15) and HÀ C(8) to HÀ C(9) ( Figure 3). The spin coupling systems from HÀ C(11') to HÀ C(15') and HÀ C(8') to HÀ C(9') established by the 1 H, 1 H-COSY spectrum as well as the HMBCs between OHÀ C(1') and C(1')/C(2')/ C(6'), between HÀ C(8') and C(7')/C(9') and between HÀ C(9') and C(11')/C(10') indicated the presence of a flavone unit (part B, Figure 3).…”

“…During our investigations on bioactive natural products from Myrtaceae plants, [3][4][5][6][7] several bioactive phloroglucinols were obtained from X. chrysanthus. [8,9] In our continuous research on this plant, the first examples of cinnamoyltriketone-flavone adducts with new skeleton, (+)-and (À )-xanchryones F and G ((+)-and (À )-1 and 2), were obtained by chiral HPLC. These compounds have the same planar structure, among which 1 and 2 are C-9' epimers, (�)-1 and (�)-2 are two pairs of enantiomers.…”

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]).…”

Xanthchrysones A–C: Rearranged Phenylpropanoyl–Phloroglucinol Dimers with Unusual Skeletons from Xanthostemon chrysanthus

“…In addition, taking account of the molecular formula, 2c was proposed to link with 2a through an ester bond. The esterification took place at the C-1 position according to the chemical shift of C-1 compared with xanchryone D, , as well as the presence of OH-4 and OH-5 in 1 . This conclusion was further confirmed by the fragment ion peak at m / z 423.1407 [C 24 H 23 O 7 + ] in the MS/MS that originated by C-1–O–C-6′ bond cleavage (Supporting Information).…”