Judul: Comparison of Apigenin, Luteolin, And Eriodictyol Contents of Indonesian and Japanese Plectranthus amboinicus (Lour) Spreng Using HPLC-MWD
Abstrak: Plectranthus amboinicus is a plant cultivated for culinary, medicinal, and decorative purposes in parts of Africa, Latin America, and Asia. Apigenin, luteolin, and eriodictyol are three examples of flavonoids identified in the plant that exhibit potential in combatting degenerative diseases, albeit the presence and concentration of said flavonoids could be impacted by cultivation conditions. With that being said, research on said flavonoids have been limited to merely identification without necessarily taking into consideration the impact of cultivation conditions on the plant. Using High-Performance Liquid Chromatography (HPLC), this research aims to compare the concentration of apigenin, luteolin, and eriodictyol of the leaves of the plant cultivated from two different areas: Indonesia and Japan. The total flavonoid content of the Japanese leaves was found to be greater than its Indonesian counterpart. Moreover, Japanese samples had a higher luteolin concentration but a lower apigenin concentration when compared to the Indonesian samples. Interestingly, eriodictyol was only present in Indonesian samples. Differences in total flavonoid content and the concentrations of apigenin, luteolin, and eriodictyol could be attributed to the differing climates of Indonesia and Japan, in which the tropical climate of Indonesia leads to greater precipitation and lower solar irradiance. With the exception of recovery, the method employed was found to have met all of the other parameters of validation. This shows the need for further optimization.
Keyword: torbangun, Plectranthus amboinicus, apigenin, luteolin, eriodictyol, flavonoid, HPLC-MWD

Judul: Chemometric Analysis of Plant Origin and Polarity Index on Total Phenolics, Flavonoids, and Antioxidant Activity of Caricature Plant (Graptophyllum pictum (L.) Griff.) Extract
Abstrak: Daun ungu (Graptophyllum pictum (L.) Griff.) adalah tumbuhan obat dari Papua Nugini dan Polinesia yang kemudian menyebar ke Indonesia. Asal tanaman, indeks polaritas pelarut, serta total fenolik dan flavonoid diduga memiliki korelasi terhadap aktivitas antioksidan daun ungu. Penelitian dilakukan bertujuan untuk mengetahui besarnya pengaruh asal tanaman, indeks polaritas pelarut, serta total fenolik dan flavonoid terhadap aktivitas antioksidan (DPPH) daun ungu menggunakan analisis PCA. Korelasi rendemen ekstrak daun ungu menghasilkan nilai korelasi Pearson sebesar 0.857 dan nilai p sebesar 0.063 serta nilai korelasi Spearman sebesar 0.872 dan nilai p sebesar 0.054. Dalam komparasi kandungan fitokimia daun ungu, sampel daun ungu asal Thailand tidak memiliki kandungan alkaloid dan glikosida. Berdasarkan kandungan fenolik, flavonoid, dan aktivitas antioksidannya, sampel daun ungu asal Indonesia dan Thailand terbagi menjadi dua jenis yang berbeda., Caricature Plant (Graptophyllum pictum (L.) Griff.) is a medicinal plant from Papua New Guinea and Polynesia which later spread to Indonesia. Plant origin, solvent polarity index, and total phenolics and flavonoids are thought to have a correlation to the antioxidant activity of purple leaves. The aim of this study was to determine the effect of plant origin, solvent polarity index, and total phenolic and flavonoid on the antioxidant activity (DPPH) of caricature plant using PCA analysis. The yield correlation of purple leaf extract resulted in a Pearson correlation value of 0.857 and a p-value of 0.063 and a Spearman correlation value of 0.872 and a p-value of 0.054. In comparison to the phytochemical content of caricature plants, caricature plant samples from Thailand did not contain alkaloids and glycosides. Based on the phenolic content, flavonoids, and antioxidant activity, caricature plant samples from Indonesia and Thailand were divided into two different types.
Keyword: Antioxidant, Flavonoid, Graptophyllum pictum, phenolic, origin, polarity index

Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik