Two new diterpenoid acids, pinusenocarp (1) and pinusenoid (2), were isolated from the pine cone of Pinus koraiensis. All the compounds were characterized on the basis of spectral analysis, viz. 1 H NMR, 13 C NMR, IR, UV, ESI-MS, and elemental analysis. Pinus koraiensis is an economically important conifer and is indigenous to the northeast region of China [1]. Plants of the genus Pinus (Pinaceae) contain diterpenoids [2, 3], triterpenoids [4], flavonoids [5], and lignans [6]. Some of them are used in folk medicine as anti-asthmatic [7], anti-cancer [8], and anti-virus agents [9]. We have focused our attention on the biologically active compounds of the cones of coniferous trees treated as wastes in the forestry industry.We have recently reported volatile oil [10] and diterpenes [11,12] from the pine cone of the Pinaceae plant.Herein we report the isolation of diterpene acids from this plant and their physicochemical properties. Diterpene acids in alcohol (DAA) were first isolated from the raw material (4.5 kg) by ethanol extraction. The EtOH fraction (780 g, 17.3%) dominated in the pine cone of P. koraiensis, which was separated by silica gel column chromatography eluted with petroleum ether (145 g), ethyl acetate (280 g), acetone (165 g), and methanol (82 g).The EtOAc fraction (35.9%) dominated in the EtOH fraction, which was subjected to silica gel column chromatography eluted with CH 3 Cl, CH 3 Cl-MeOH (9:1; 8:2; 7:3; 1), and MeOH, and six fractions (A-F) were colleted on the basis of TLC.During the investigation of the chemical constituents of this plant, two new diterpenoid acids from fraction D in the EtOAc extract of the cone of P. koraiensis have been isolated for the first time. In this paper, we present the isolation and structural elucidation of two new diterpenoid acids.Column chromatography of various fractions of the ethanol extract isolated two new diterpenoid acids, which we called pinusenocarp (1) and pinusenoid (2).Pinusenocarp (1). Elemental analysis agrees with the molecular formula C 17 H 24 O 4 , mp 175-176qC. This molecular formula was confirmed by ESI-MS, m/z at 315 [M + Na]. The UV and IR spectra of 1 showed the presence of hydroxyl groups 1)
A new type of CO 2 laser resonator with hole-coupling output is presented in this paper. The laser beam in the resonator is focused into the reflector assembly system composed of a reflector with a small central hole and an output mirror with a central coupling hole. According to the theory of diffraction optics, the laser optical field distribution in the cavity and the far-field distribution are analyzed by numerical calculation. In the experiment, the variations of the laser output power with continuous current discharged is measured. The maximum laser output power is 14.5W at the discharge current 12mA. The laser power distribution of the output beam at the distance of 1m is measured, and the result is in good accordance with numerical calculation. The laser cavity with hole-coupling can be used in intracavity pumped THz laser output and other types of intracavity pumped lasers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.