Sulfur-Containing Aristoloxazines and Other Constituents of the Roots of Aristolochia orbicularis

Abstract

Six new compounds, aristoloxazine A (1), aristoloxazine B (2), 7-methoxytaliscanine (3), humul-7-en-1,4,11-triol (4), 8-hydroxy-β-logipinene (5), and 1β-hydroxy-4(14)-eudesmene (6), corresponding to two sulfur-containing aristoloxazines (1 and 2), an aristolactam (3), and three sesquiterpenes (4-6) were isolated, along with 26 known compounds, from the roots of Aristolochia orbicularis. The structures of the new compounds were established based on their spectroscopic and spectrometric data and in the case of aristoloxazine A (1) by single-crystal X-ray crystallography. This is the first report of sulfur-containing aristoloxazines from a natural source. Furthermore, aristoloxazine A (1) was found to possess potent in vitro antimicrobial activity against all resistant Staphylococcus aureus and several fungal strains in which it was evaluated.

Asaroidoxazines from the Roots of Asarum asaroides Induce Apoptosis in Human Neuroblastoma Cells

“…Asaroidoxazines A ( 1 ) and B ( 2 ) represent the third and fourth examples, respectively, of aristolochic acid derivatives that contain oxazinone on the phenanthrene nucleus. They are related to the previously reported aristoloxazines A and B, which were the first aristolochic acid derivatives with an oxazinone moiety isolated from the genus Aristolochia . A plausible biosynthetic pathway for 1 and 2 is suggested in Scheme .…”

“…They are related to the previously reported aristoloxazines A and B, which were the first aristolochic acid derivatives with an oxazinone moiety isolated from the genus Aristolochia. 22 A plausible biosynthetic pathway for 1 and 2 is suggested in Scheme 1. Nitroreduction and intramolecular nucleophilic acyl substitution reaction of aristolochic acid derivatives, which can be biosynthesized from L-tyrosine through benzylisoquinoline alkaloids, 23,24 should give N-hydroxydihydrooxazinone intermediates (i).…”

Phenanthrene Derivatives from Asarum heterotropoides Showed Excellent Antibacterial Activity against Phytopathogenic Bacteria

“…This kind of phenanthrene derivative is extremely scarce in nature; only two (aristoloxazine A and B) were isolated from Aristolochia orbicularis in 2017. 37 This study offers the first report on phenanthrene derivatives with this structural feature isolated from genus Asarum. Table 3 shows that phenanthrene derivatives are the main active components of the A. heterotropoides extract.…”

“…Comparing the 13 C and 1 H NMR data of compound 1 with aristoloxazine A (2) 37 (Figure 1) demonstrates that they have the same skeleton. The main difference is that the signals for the methoxy groups at C-1 and C-2 in aristoloxazine A were substituted by signals for a methylenedioxy group (δ H : 6.46, 6.55) in 1 from the HMBC cross-peaks from H-dioxymethylene to C-1 and C-2 (Figure 2).…”

Unprecedented Reactivity of β‐Iodovinyl Sulfones: An Efficient Synthesis of β‐Keto Sulfones and β‐Keto Thiosulfones

“…Organosulfur compounds have paid significant attention due to a large number of natural products[1a], [1g] and indispensable bioactive compounds;[1d], [1e], [1h] they also widely used in materials chemistry. [1c] Among them, the β‐keto sulfones are the privileged class of compounds in various biological activities, such as antibacterial, antifungal, and nonnucleoside inhibitors Extensive efforts have been devoted to the synthesis of β‐keto sulfones and also used in several promising synthetic transformations . Among these approaches, searching for alternative metal‐free efficient methods to construct of β‐keto sulfones is still desirable.…”