New Azafluorenone Derivative and Antibacterial Activities of Alphonsea cylindrica Barks

Abstract

− A phytochemical study of Alphonsea cylindrica King (unreported) has led to the isolation of six alkaloids. The compounds were identified as kinabaline (1; azafluorenone alkaloid), muniranine (2), O-methylmoschatoline (3; oxoaporphine alkaloid), lysicamine (4), atherospermidine (5) and N-methylouregidione (6; 4, 5-dioxoaporphine alkaloid). The structures of the isolated compounds were determined based on the spectroscopic techniques and by comparison with data reported in the literature. Alkaloid 2 was isolated as a new derivative of azafluorenone while alkaloids 1, 3 -6 were isolated for the first time from Alphonsea species. In addition, alkaloid 3 and 4 showed inhibition zone against Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus in disc diffusion test. The minimum inhibition concentration (MIC) values of lysicamine (4) against S. aureus, B. cereus and P. aeruginosa were found to be smaller than O-methylmoschatoline (3). Therefore, the reported antibacterial activity showed the potential of this plant as natural antibacterial agent and supported the documented traditional use of Alphonsea sp. in the treatment of diarrhea and fever.

Morphinan Alkaloids from the Leaves of Alphonsea cylindrica and Their Antibacterial Properties

“…11. References: "Its distributed in the lowland of Southeast Asia [1,2],". It is not clear, why [2] (Two new isoquinoline alkaloids from the bark of Alphonsea cylindrica King and their antioxidant activity) is cited here as it does not seem to present any data on the geographic distribution of the plant.…”

“…Also, correct "its". "Its distributed in the lowland of Southeast Asia [1,2], including Malaysia [2,3,4], Thailand [5], Singapore [6], and so on [5,6]". Please do not write "and so on" if there is no logical sequence.…”

“…cylindrica [1,3,18]. These studies reported the isolation of aporphine, azafluorenone [1,3] and isoquinoline alkaloids [3], and steroids [18] from the bark of A. cylindrica.…”

“…1 H (500 MHz) and13 C (125 MHz) NMR data of compounds 1-3.J-values are in parentheses and reported in Hz; chemical shifts are given in ppm; assignments were confirmed by DEPT, COSY, HMQC, and HMBC experiments. All data measured in CDCl 3 .…”

Isolation of a Morphinan Alkaloid and a Methoxybenzoic Acid with The Investigation on The Antibacterial Effect of Alphonsea cylindrica King Leaves

“…Currently, extensive phytochemical and pharmacological studies on A. cylindrica are still lacking with only limited studies had been done on the plant [13,14]. Talip et al [14] had successfully isolated different types of alkaloids from the bark of A. cylindrica, known as azafluorenone (kinabaline), oxoaporphine (O-methylmoschatoline), and 4, 5dioxoaporphine (N-methylouregidione) alkaloids. The isolated compounds have shown inhibition ability against bacteria such as S. aureus, P. aeruginosa, and B. cereus.…”